Digitized by the Internet Archive in 2007 with funding from IVIicrosoft Corporation 'w.archive.ora/details/demonstrationsofOOellirich 394 DISSECTION OF THE PERINiEUM. The anterior branch (') passes under the transverse muscle, and accom- panies the other to the scrotum.. Muscular otlsets are furnished by it to the levator ani and the other superficial muscles. The superficial perinatal branches communicate with one another, and the posterior is joined by the inferior pudendal nerve. At the scrotum they are distributed by long slender filaments, which reach as far as the under surface of the penis. In the female these nerves supply the labia pudendi. Other muscular branches of the pudic will be afterwards examined (p. 399). The inferior pudendal nerve (*) is a branch of the small sciatic. It pierces the ftiscia lata about one inch in front of the ischial tuberosity, and enters beneath the superficial fascia of the perinaeum, to end in the outer and fore parts of the scrotum. Communications take place between this nerve, the inferior liaRmorrhoidal, and the posterior of the two superficial perinaeal branches. In the female the inferior pudendal nerve is distri- buted to the labium. Dissection. For the display of the muscles, the fatty layer, as well as the vessels and nerves of the left side, must be taken aw^ay from the ante- rior half of the perinaeal space. Afterwards a thin subjacent aponeurotic layer is to be removed from the muscles. Along the middle line lies the ejaculator urinae ; and in cleaning it the student is to follow two fasciculi of fibres from it on the same side — one in front, the other behind. On the outer part of the space is the erector penis. And behind, passing obliquely between the other two, is the transverse muscle. The student should seek, on the right side, the branches of the two superficial perinaeal nerves to the underlying muscles ; and beneath the transversalis, an offset of the perinaeal branch which supplies the deep muscles and the urethra. Muscles (fig. 130). Superficial to the triangular ligament in the ante- rior half of the perinaeal space, are three muscles, viz., the erector penis, the ejaculator urinae, and the transversalis perinaei. Other muscles of the urethra are contained between the layers of the triangular ligament, and will be subsequently seen. Central point of the perinceum. Between the urethra and the rectum is a white fibrous spot, to which this term has been applied. It occupies the middle line, half an inch in front of the anus. In it the muscles acting on the rectum and the urethra are united ; and it serves as a common point of support to the space. The ERECTOR PENIS (fig. 130, ^) is the most external of the three mus- cles, and is narrower at each end than in the middle. It covers the crus penis; and its fibres arise horn, the ischial tuberosity farther back than the attachment of the penis, and from the bone on each side of the crus. Su- periorly the muscle is inserted into the inner and outer surfaces of the crus penis. It rests on the root of the penis and the bone. Action. The muscle compresses the crus penis against the subjacent bone, and retards the escape of the blood from that organ by the veins : in that way it will contribute to the continuance of distension. The EJACULATOR URiN^ muscle (fig. 130, ^) lies on the urethra. The muscles of opposite sides unite by a median tendon along the middle line and in the central point of the perinaeum (origin). The fibres are directed outwards, curving around the convexity of the urethra, and give rise to a thin muscle, which has the following insertion: — The most posterior fibres SUPERFICIAL MUSCLES OF URETHRA. 395 are lost on the front of the triangular ligament. The anterior fibres, which are the longest and best marked, are inserted into the penis on its outer aspect before the erector ; and, according to Kobelt,^ they send a tendinous expansion over the dorsal vessels of the penis. Whilst the middle or in- tervening fibres turn round the urethra, surrounding it for two inches, and join its fellow by a tendon. The ejaculator muscle covers the bulb and the urethra for three inches in front of the triangular ligament.^ If the muscle be cut through on the right side, and turned off the urethra, the junction with its fellow above that tube will be apparent. Action. The two halves, actino; as one muscle, can diminish the urethra, and eject forcibly its contents. During the flow of fluid in micturition the fibres are relaxed, but they come into use at the end of the process, when the passage has to be cleared. The action is involuntary in the emission of the semen. The TRANSVERSALS PERiN^T (fig. 130, ^) is a small thin muscle, which lies across the perinjeum opposite the base of the triangular ligament. Arising fvov[\ the inner surface of the pubic arch near the ischial tuberosity, it is inserted into the central point of the periniieum with the muscle of the opposite side, and with the sphincter ani and the ejaculator urinas. Be- hind this muscle the superficial fascia bends down to join the triangular ligament. Sometimes there is a second small fleshy slip, anterior to the transver- salis, which has been named transversalis alter ; this throws itself into the ejaculator muscle. Action. From the direction of the fibres the muscle will draw back- wards the central point of the perinjeum, and help to fix it, preparatory to the contraction of the ejaculator. The three muscles above described, when separated from each other by the dissection, limit a triangular space, of which the ejaculator urinre forms the inner boundary, the erector penis the outer side, and the trans- versalis perinaei muscle the base. In the area of this interval is the trian- gular ligament of the urethra, with the superficial perineeal vessels and nerves. Should the knife enter the posterior part of this space during the deeper incisions in the lateral operation of lithotomy, it will divide the transverse muscle and artery, and probably the superficial perinaeal vessels and nerves. Dissection (fig. 131). For the display of the triangular ligament, the muscles and the crus penis, which are superficial to it, are to be detached in the following way: — On the left side the ejaculator urinas is to be re- moved completely from the front of the ligament, and the erector muscle from the crus of the penis. Next, the crus penis is to be detached from the bone ; but this must be done with care so as not to cut the triangular ■ ligament, nor to injure, near the pubes, the terminal branches of the pudic artery and nerve to the penis. On the right side the dissector should trace out beneath the transversalis * Die Mannlichen und Weiblichen Wollust-Organe, von G. L. Kobelt, 1844. 2 Some of the deeper fibres which immediately surround the bulb, have been described as a separate stratum by Kobelt. These are separated from the super- ficial layer by thin areolar tissue, and join the corresponding part of the other muscle by a small tendon above the urethra. The name compressor hemisphcerium hulhi has been proposed for it by that anatomist. € DEMONSTRATIONS ANATOMY; GUIDE TO THE KNOWLEDGE OP THE HUMAN BODY DISSECTION. BY GEOEGE YINER /ELLIS, EMERITUS PROFESSOR OP ANATOMY IN UNIVERSITY COLLEGE, LOND'ON'. FROM THE EIGHTH AND REVISED ENGLISH EDITION. ILLUSTRATED BY TWO HUNDRED AND FORTY-NINE ENGRAVINGS ON WOOD. /S7? PHIL/A DELPHIA: HE\N"EY 0. LEA 1879. PREFACE The plan of this work is designed to teach the Anatomy of the Human Body by dissection in successive stages after the following manner : — In the dissection of a Part the attention of the Student is directed first to the superficial prominences of bone and muscle, and to the hollows that point out the situation of the subjacent vessels. Next the cutaneous structures, and the different* layers of muscles with their appertaining vessels and nerves are examined in succession, so that the several objects between the surface of the Body and the bones may be observed in much the same order as they would be met with in a Surgical operation. And, lastly, the joints and liga- ments receive due notice. In the dissection also of the viscera and the organs of the senses the manner in which the composition of each may be shown, is fully indicated for the guidance of the Student. The Anatomical description of the Part under examination is arranged in conformity with the dissection in regions, and each muscle, bloodvessel, nerve, or other structure, is described only to such an extent as it may be laid bare. Since the publication of the last edition great changes have been made in textural Anatomy; and the chief of these, for which I am indebted to Quain's Anatomy, I have introduced into my account of the microscopic structure of the diflferent organs. In this edition, as in the preceding ones, I have endeavored to make the work more complete by the correction of inaccuracies, and to render it morfe efficient as a guide to practical work. G. V. ELLIS. October, 1878. CONTENTS CHAPTER I. DISSECTION OF THE HEAD AND NECK, Section 1. External Parts of tlie Head 2. Internal Parts of the Head 3. The Face .... 4. The Orbit .... 5. The Neck, right side Posterior triangular space Front of the Neck Anterior triangular space 6. Pterygo-maxillary Region . 7. Submaxillary Region 8. Superior Maxillary Nerve and Vessels 9. Deep Vessels and Nerves of the Neck 10. Left side of the Neck 11. The Pharynx 12. The Mouth . "* . 13. Cavity of the Nose . 14. Spheno-palatine and Otic Ganglia, Facial Internal Maxillary Artery 15. The Tongue .... 16. The Larynx .... 17. Hyoid Bone, Cartilages and Ligaments of the Larnyx, Structure of the Trachea .... 18. Prevertebral Muscles and the Vertebral Vessels 19. Ligaments of the first two Cervical Vertebrae, and of the Clavicle and Nasal Nerves, and PAGE 17 24 34 50 61 63 67 69 87 97 103 105 118 122 132 133 138 146 151 158 163 166 CHAPTER II. DISSECTION OF THE BRAIN. Sectiox 1. Membranes and Vessels 2. Origin of the Cranial Nerves 3. Medulla Oblongata and Pons Varolii 172 177 182 VI CONTENTS. PAGE Section 4. The Cerebnim, or Great Brain . . . . .189 The under surface, or the Base . 190 The upper surface and lobes . . 193 Convolutions . . 195 The Interior . 199 Ventricles of the Brain . 200 Floor of the lateral Ventricle . . 203 Central Parts of the Cerebrum . 205 Structure of the Cerebrum 209 5. The Cerebellum, or little Brain Surfaces and Lobes 211 212 Structure of the Mass . 215 Fourth Ventricle , 217 CHAPTER III. DISSECTION OF THE UPPER LIMB. Section 1. The Wall of the Thorax .... The Axillary Space .... 2. Scapular Muscles, Vessels, Nerves, and Ligaments 3. The Front of the Arm .... Back of the Arm .... 4. The Front of the Forearm .... 5. The Palm of the Hand .... 6. The Back of the Forearm .... 7. Ligaments of the Shoulder, Elbow, Wrist, and Hand" 224 228 240 248 257 260 272 282 290 CHAPTER IV. DISSECTION OF THE THORAX. Section 1. Cavity of the Thorax ...... 305 The Pleurae . . . . . . .307 Connections of the Lungs ..... 308 The Pericardium ...... 310 The Heart and its large Vessels .... 312 Nerves of the Thorax ...... 329 The Trachea and the Characters and Structure of the Lung 333 •Parts in Front of the Spine, and the Cord of the Sympathetic 336 Parieties of the Thorax ..... 342 2. Ligaments of the Trunk ...... 343 Articulation of the Ribs to the Vertebrae . . . 343 Articulation of the Ribs to the Sternum . . . 346 Articulations of the Sternum ..... 346 Articulations of the Vertebrae .... 346 CONTENTS, vn CHAPTER V. DISSECTION OF THE BACK. First Layer of Muscles .... Second Layer of Muscles Third Layer of Muscles Fourth Layer of Muscles with Vessels and Nerves Fifth Muscular Layer, and the Sacral Nerves PAGE 354 358 359 361 369 CHAPTER VI. DISSECTION OF THE SPINAL CORD. Membranes of the Cord .... Roots of the Spinal Nerves .... Vessels of the Cord ..... Form and Divisions of .the Cord Structure of the Cord, and the deep Origin of the Nerves Intraspinal Vessels ..... 374 377 379 380 382 384 CHAPTER VII. DISSECTION OF THE PERINEUM. Section 1. Perinseum of the Male Posterior Half of the Space Anterior Half of the Space Lateral Operation of Lithotomy 2. Perinseum of the Female 386 387 391 399 400 CHAPTER YIII. DISSECTION OF THE ABDOMEN. Section 1. Wall of the Abdomen ...... 404 2. Hernia of the Abdomen . . . . . .420 3. Cavity of the Abdomen . . . . . .430 Connections of the Viscera ..... 431 Peritoneum and its Folds ..... 435 Mesenteric Vessels, and Part of the Sympathetic Nerve . 439 Connections of the Aorta and Vena Cava . . . 444 Connections of the Duodenum and Pancreas . . . 445 Coeliac Axis and Vena Portae ..... 446 Sympathetic and Vagus Nerves .... 450 4. Anatomy of the Abdominal Viscera .... 452 The Stomach . . . . . . .452 The Small Intestine . . . . . .456 The Large Intestine ...... 461 Vlll CONTENTS. Section 4. Anatomy of the Abdominal Viscera — continued. The Pancreas . The Spleen The Liver The Gall Bladder The Kidney and the Ureter The Suprarenal Body . The Testis and the Vas Deferens 5. Diaphragm with Aorta and Vena Cava Deep Muscles of the Abdomen 6. Lumbar Plexus and the Cord of the Sympathetic Nerve PAGE 464 465 466 472 473 478 479 484 492 495 DISSECTION OF THE PELVIS. Section 1. Fascia of the Cavity and the Muscles of the Pelvic Outlet 2. Connections of the Viscera in the Male 3. Connections of the Viscera in the Female . 4. Vessels and Nerves of the Pelvis . 5. Anatomy of the Viscera of the Male . . . The Prostate (Hand and the Seminal Vesicles The Urinary Bladder .... The Urethra and the Penis The Rectum ..... 6. Anatomy of the Viscera of the Female Genital Organs ..... The Vagina ..... The Uterus ..... Ovaries and Fallopian Tubes . Bladder, Urethra, and Rectum 7. Internal Muscles of the Pelvis Articulations of the Pelvis 499 503 509 513 520 521 524 526 532 533 533 535 537 539 541 542 543 CHAPTER IX. DISSECTION OF THE LOWER LIMB. Section 1. The Front of the Thigh . . . . * . .552 Femoral Hernia ...... 559 Scarpa's Space ....... 563 Deep Muscles, Vessels, and Nerves on the Front of the Thigh 565 Deep parts on the inner Side of the Thigh . . .574 2. The Buttock, or the Gluteal Region . . . .581 3. The Back of the Thigh . . . . . .592 The Popliteal Space . . . . . .593 Hamstring Muscles and Vessels .... 597 The Hip-Joint . . . . . . .600 4. The Back of the Leg . . . . . . 605 5. The Sole of the Foot . . . . . .614 6. The Front of the Leg and the Dorsum of the Foot . . 626 7. Ligaments of the Knee, Ankle, and Foot .... 634 CONTENTS. IX CHAPTER X. DISSECTION OF THE EYE. Sclerotic Coat and Cornea Clioroid Coat and Ciliary Processes Ciliary Muscle . The Iris Ciliary Vessels and Nerves Chamber of the Aqueous Humor The Retina and Jacob's Membrane Vitreous Body, and Hyaloid Membrane the Canal of Petit. Crystalline Lens and its Capsule with the Suspensory Ligament and PAGE 655 659 660 661 663 663 663 66Q 668 CHAPTER XI. DISSECTION OF THE EAK. The Auditory Canal The Tympanum, with its Vessels and Nerves Ossicles of the Tympanum andftheir Muscles The Osseous Labyrinth of the Inner Ear Vestibule .... Semicircular Canals Cochlea, its Septum and Passages Organ of Corti The Membranous Sacs, or Labyrinth . Utricle . . • . Saccule Bloodvessels of the Labyrinth . Nerves of the Cochlea and Membranous Sacs . . 670 . . 671 and Ligaments . 674 . . 679 . 679 . . 680 . 681 . . 684 . . . 685 . . 685 . . 686 . 687 . . . . 687 LIST OF ILLUSTRATIONS. FIG. 1. Extrinsic muscles of the ear . . 2. Cutaneous nerves and arteries of the scalp 3. Some of the sinuses of the skull 4. Cranial nerves in the base of the skull 5. Muscles of the nose 6. Muscles of the mouth 7. Lateral cartilages of the nose 8. Muscles on the outer and inner surface of the ear cartilage 9. Cutaneous branches of the fifth nerve in the face 10. First view of the orbit 11. Second view of the orbit . 12. Third view of the orbit 13. The eyelids and lachrymal apparatus 14. Part of the posterior triangle of the neck 15. View of the anterior triangular space of the neck 16. A vievv of the common carotid and subclavian arteries 17. External carotid and its superficial branches 18. Superficial view of the pterygoid region 19. Ligaments of the jaw — an inner view 20. A view of the interior of the compound temporo-maxillary joint 21. Deep view of the pterygoid region 22. Muscles of the tongue ..... 23. Deep view of the submaxillary region 24. Diagram of the upper maxillary nerve and its branches 25. Deep vessels and nerves of tlie neck 26. Diagram of the eighth nerve .... 27. Diagram of the ending of the lymj)h duct and the thoracic duct in the veins ..... 28. External view of the pharynx 29. Internal view of the pharynx 30. Muscles of the soft palate 31. Spongy bones and meatuses of the nasal cavity 32. Magnified vertical section of the mucous membrane of the nose 33. Nerves of the septum of the nose 34. Nerves of the nose and palate 35. Nerves joining the enlargement of the facial nerve 36. Inner view of the otic ganglion . 37. Muscles on the surface of the tongue 38. Intrinsic muscles of the tongue . 39. Front view of the larynx .... 40. Hinder view of the larynx 41. View of the internal muscles of the larynx Xll LIST OF ILLUSTRATIONS FIG. 42. 43. 44. 45. 46. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. Vocal apparatus, on a vertical section of the larynx Hyoid bone and the laryngeal cartilages View of the vocal cords and crico- thyroid ligaments Deep muscles of the front of the neck and the scaleni muscles External ligaments in front between the atlas and axis and the occipital bone ...... External ligaments behind between the atlas and axis and the occipital bone ........ Internal ligament between occipital bone and axis Internal ligaments between the occipital bone and the atlas and axis First vertebra with the odontoid process removed from the socket formed by the bone and the transverse ligament Ligaments of the inner end of the clavicle, and of the cartilage of the second rib .... . Arteries at the base of the brain . Origin of the cranial nerves Anterior view of the medulla oblongata and pons Hinder view of the medulla oblongata . Fibres of the medulla, pons, and crus cerebri Fibres of the lateral tract and of the olivary body Tranverse section of the medulla oblongata above the middle of the olivary body ..... Under surface of the brain Lobes of the hemisphere, and convolutions and fissures of the outer surface of the brain ..... View of the orbital lobule and the central lobe of the brain Convolutions and fissures on the inner face of the hemisphere of the brain ........ View of the lateral ventricles of the brain Second view of the dissection of the brain Connection posteriorly between the cerebrum, the medulla oblongata and cerebellum ....... Under part of the cerebellum, seen from behind View from behind of the under surface of the cerebellum View of the third and fourth ventricles of the brain View of the dissected axilla ..... Second view of the dissection of the thorax Diagram of the serratus magnus muscle .... View from behind of the attachments of the triangularis sterni muscle View of the subscapularis and the surrounding muscles View of the muscles of the dorsum of the scapula, and of the circumflex vessels and nerve ...... Ligaments of the clavicle and scapula, and of the shoulder joint Cutaneous veins and nerves at the bend of the elbow . Axillary and brachial arteries and their branches Muscles and deep vessels and nerves of the arm Dissection of the dorsal scapular vessels and nerve, and of the triceps muscle of the arm .... Superficial view of the forearm . Dissection of the deep layer of muscles of the forearm, and of the vessels and nerves between the two layers of muscles of the forearm 268 LIST OF ILLUSTRATIONS, Xlll FIG. 82. 83. 84. 87. 89. 90. 91. 92. 93. 94. 95. 96. 97. 99. 100. 101. 102. 103. 104. 105. 106. 107. 108. 109. 110a 110b 111. 112. 113. 114. 115. 116. 117. 118. 119. The extensor tendon of the finger with its accessory muscles and the sheatli of the flexor tendons ...... Dissection of the superficial vessels and nerves of the palm of the hand with some of the superficial muscles .... Deep dissection of the palm of the hand ... Three palmar interosseous muscles .... Four dorsal interosseous muscles .... Superficial layer of muscles on the back of the forearm, with some ves sols ........ Dissection of the deep layer of muscles, and the vessels and nerve on the back of tlie forearm ...... View of the interior of the shoulder-joint The ligaments of the elbow joint, and the shaft of the radius and ulna View of the orbicular ligament of the radius . Front view of the articulations of the wrist joint, and carpal and me tacarpal bones ....... The wrist joint opened to show the arch formed by the bones of the forearm with the uniting fibro-cartilage Articulations of the carpal bones .... Posterior ligaments of the wrist, and carpal and metacarpal bones Union of metacarpal bone and first phalanx Diagram to show the difi"erence in the anterior border of the right and left lung ....... Diagram showing the position of the heart to the ribs and sternum Back of the heart with the coronary sinus and its veins Diagram of the two cavities of the right side of the heart Diagram of the two cavities of the left side of the heart Muscular fibres of the auricles ..... A diagram of the arrangement of the fibres in layers in the left ven tricle ........ The formation of the septum ventriculorum by the fibres of both ven tricles ......... Arch of the aorta and its great vessels .... View of the thoracic duct, and the intercostal veins Scheme to illustrate the connection between the spinal and sympathetic nerves ........ Ligaments of the ribs and vertebra .... Anterior common ligament of the bodies of the vertebrje . View of the posterior common ligament of the vertebrae of the neck , View of the posterior common ligament of the vertebrae of the loin Intervertebral substance in the lumbar region ... Vertical section of the int,ervertebral substance A horizontal cut through an intervertebral fibro-cartilage An inner view of the neural arches of the vertebrae, with their inter posed ligaments ...... Ligaments of the processes of the vertebrae, and of the ribs . Muscles of the back . . . Part of the third layer of the back-muscles Dissection of the muscles underneath the splenius Deep dissection of the back of the neck 273 XIV LIST OF ILLUSTRATIONS FIG. 120. Dissection of sacral nerves ..... 121. Lower end of the dura mater, with its central and lateral processes 122. View of the membranes of the spinal cord 123. Roots of the spinal nerves ..... 124. Membranes of the spinal cord laid open 125. A section of the spinal cord, to show its composition, and its divisions 126. Tlie gray substance in the interior of tlie spinal cord . 127. Intraspinal arteries in the loins .... 128. Intraspinal veins in the loins .... 129. A view of the dissection of the rectal half of the perinaeum 130. Superficial dissection of the anterior half of the perinseum 131. Deep dissection of the perinaeum 132. The symphysis pubis seen from behind . 133. The female perinseum ..... 134. The muscles of the female perinseum 135. Dissection of the first lateral muscle in the wall of the belly 136. Internal oblique muscle of the abdominal wall 137. The lower part of the internal oblique with the Cremaster muscle and the testicle ...... 138. Dissection of the third lateral muscle in the wall of the belly 139. Rectus muscle of the abdomen .... 140. Dissection for inguinal hernia .... 141. View of the parts concerned in femoral hernia . 142. Connections of the liver, stomach, spleen, and large intestine 143. Superior mesenteric artery and its branches 144. The lower mesenteric artery, and the aorta 145. View of the coeliac axis, and of the viscera to which its branches are supplied ...... 146. Vena portae and the veins joining it . 147. Diagram representing the arrangement of the muscular fibres of the stomach ....... 148. Alveolar depressions of the mucous membrane of the stomach 149. Enlarged representation of the tubes of the stomach . 150. The. duodenum opened showing the valvulse conniventes, and the opening of the bile duct ..... 151a. Vessels of the villi in the mouse, injected by Gerlach 151b Lacteals and plexus of vessels in two villi, injected by Teichman 152a. Patch of Peyer's glands four times enlarged . 152b. Magnified representation of an injection of the vessels surrounding and penetrating the follicles in a patch of Peyer in the rabbit 153a. A piece of mucous membrane enlarged 153b. a piece of mucous membrane enlarged « . 154. Magnified view of the mucous membrane of the duodenum 155. Interior of the caecum dried and laid open 156a. Enlarged view of *' a solitary gland" . 156b. Enlarged view of " a solitary gland" . 157. A drawing of the trabecular structure of the spleen of the ox 158. Under surface of the liver .... 159. A magnified representation of the hepatic cells . 160a.. Lobules of the liver, magnified PAGE 372 375 375 380 LIST OP ILLUSTRATIONS XV FIG. 160b. Lobules of the liver, magnified .... 161. Vessels in a portal canal, and the lobules of the liver . 162. Gall-bladder and its duct ..... 163. Section through the kidney ..... 164. Plan of the arrangement of the uriniferal tubes 165. Plan of contorted urine tubes ending in Malpighlan corpuscles 166a. Plan of the vessels connected with the urine tubes 166b. Plan of the vessels connected with the urine tubes 167. Vertical section of the suprarenal body .... 168. The testis with the tunica vaginalis laid open . 169. Vertical and horizontal sections of the testis . 170. Under surface of the diaphragm ... . . 171. Deep view of the muscles, vessels, and nerves of the abdominal cavity 172. Dissection of the lumbar plexus and its branches 173. Side view of the muscles in the outlet of the pelvis 174. Side view of the dissected male pelvis .... 175. Side view of the female pelvis ..... 176. Dissection of the internal iliac artery .... 177. Dissection of the sacral nerves and plexus 178. View of the under part of the bladder with the vesiculae seminales and vasa deferentia ...... 179. Muscular fibres of the bladder, prostate, and urethra . 180. Section through the bladder, prostate, and urethra 181. View of the lower part of the bladder and of the urethra laid open 182. View of the fibres of the case of the corpus cavernosum 183. Pectiniform septum of the penis .... 184. Magnified view of the trabecular structure and arteries of the penis 185. RejDresentation of the clitoris ..... 186. Venous plexuses of the genital organs and opening of the vagina 187. Interior of the uterus, with a posterior view of the broad ligamen and the uterine appendages ..... 188. Ovary during the child-bearing period laid open 189. Irregular piece of cartilage in the sacro-iliac articulation 190. Sacro-sciatic ligaments ...... 191. Ligaments of the symphysis pubis, thyroid hole, and acetabulum 192. Cutaneous nerves on the front of the thigh 193. Dissection of the superficial parts of the thigh 194. Dissection of the crural sheath ..... 195. Dissection on Scarpa's triangular space 196. Surface view of the front of the thigh, the teguments and fascia being removed ....... 197. Deep part of the femoral artery and its branches, with muscles of the thigh ........ 198. Deep dissection of the adductor muscles with their vessels and nerves 199. Superficial view of the buttock of the left side 200. Second view of the dissection of the buttock 201. Third view of the dissection of the buttock 202. View of the popliteal space ..... 203. Dissection of the back of the thigh .... 204. Fore part of the capsule of the hip joint . . • PAGE 470 471 473 474 476 476 477 477 479 480 482 485 488 496 501 505 511 514 519 XVI LIST OF ILLUSTRATIONS, e patella thrown down tilages attached and the met a FIG. 205. Hinder part of the hip-joint capsule? 206. Hip joint opened 207. First view of the back of the leg 208. Second view of the back of the leg 209. Deep dissection of the back of the leg . 210. First view of the sole of the foot 211. Second view of the sole of the foot 212. Third view of the sole of the foot 213. Fourth view of the sole of the foot 214. Cutaneous nerves of the front of the leg and foot 215. Anterior tibial vessel and muscles 216. External ligament of the knee-joint 217. Internal ligament of the knee-joint ' . 218. The capsule of the knee-joint cut across, andtl to show the named folds of the synovial sac 219. Interarticular ligaments of the knee-joint 220. View of the head of the tibia with the fibro-ca 221. Internal lateral ligament of the ankle . 222. External lateral ligament of the ankle . 223. View of the dorsal ligaments of the tarsus 224. Plantar ligaments of the foot 225. View of the inferior ligaments of the tarsal bones 226. Dorsal ligaments uniting the tarsus to the metatarsus tarsal bones to each other behind 227. Diagram of a horizontal section of the eyeball 228. Vertical section of the cornea 229. Inner view of the front of the choroid coat 230. Pigment cells of the eyeball 231. View of the front of the choroidal coat and iris 232. Distribution of the nerves and vessels of the iris 233. Objects on the inner surface of the retina 234. Magnified vertical section of the retina 235. Enlarged representation of the parts of the eyeball on one side opposit the lens ..... 236. A representation of the laminae in hardened lens 237. Views of the lens fibres after Henle 238. Vertical section of the meatus auditorium and tympanum 239. View of the inner wall of the tympanum enlarged 240. Inner view of the membrana tympani in the foetus 241. The three ossicles of the tympanum 242. Plan of the ossicles in position in the tympanum 243. Jacobson's nerve in the tympanum 244. View of the vestibule obtained by cutting away the outer boundary of a foetus ..... 245. Representation of the semicircular canals enlarged 246. Section through the cochlea 247. A diagram of a section of the tube of the cochlea enlarged 248. Petrous bone partly removed to show the membranous labyrinth in place ...... 249. Distribution of nerves to the membranous labyrinth DEMONSTRATIONS OF ANATOMY, CHAPTEE I. DISSECTION OF THE HEAD AND NECK. Section I. EXTERNAL PARTS OF THE HEAD. Directions. In the dissection of the head and neck, the student should endeavor to learn the parts described in the first fifty-one pages, before the position of the body is changed ; but if want of time necessitates an omission of some part, the examination of the facial nerve (p. 47) can be best deferred till a subsequent stage. The orbit on one side, the poste- rior triangular space on both sides of the neck, and the exterior and the interior of the head, should be examined whilst the body lies in its first position on the Back. Position. The student begins with the dissection of the scalp and tlie muscles of the ear. To obtain the best position, raise the head to a suitable height, and turn the face to the right side. On the left side the muscles are to be seen, and on the opposite half the vessels and nerves are to be displayed. Extrinsic muscles of the Ear. Three muscles attach the ear to the side of the liead. Two are above it, one elevating, the other drawing it forwards ; and the third, a retrahent muscle, is behind the ear. There are other special or intrinsic muscles of the cartilage of the ear, which will be afterwards described. Dissection. When the ear has been drawn down by hooks, the position of the upper muscle will be indicated by a slight prominence between it and the head ; and the muscular fibres may be laid bare by means of the two following incisions, made no deeper than the skin : One is to be car- ried upwards on the side of the head, for about three inches, along the cutaneous ridge before mentioned ; and the other, about the same length, is to be directed from before backwards close above the ear, so that the two may join at a right angle. On carefully raising the flaps of skin from below upwards, and removing the subjacent tissue, a thin fan-shaped muscular layer will come into view — the more anterior fibres constituting the attrahens, and the posterior the attollens aurem muscle. On drawing forwards the ear a ridge marks the situation of the posterior muscle. To remove the integuments, let the scalpel be drawn about an inch behind the ear, from the transverse cut above as far as to a level with 2 18 DISSECTION OF THE HEAD. the lobule of the ear, and then forwards below the lobule. After the piece of skin included by those cuts has been reflected towards the ear, the retrahent muscle must be sought beneath the subcutaneous tissue ; it consists of rounded bundles of fibres, and is stronger and deeper than the others. The ATTRAiiENS AUREM (fig. 1, ^^) is a Small fan-shaped muscle, and, arises from the fore part of the aponeurosis of the occipito-frontalis. Its fibres are directed backwards, and are inserted into a projection on the front of the rim of the ear. Beneath it are the superficial temporal vessels and nerve. The ATTOLLENS AUREM (fig. 1 , ^^) has the same form as the preceding, though its fibres are longer and better marked. Arising also from the tendon of tlie occipito-frontalis, the fibres converge to their insertion into the inner or cranial surface of the pinna of the ear — into an eminence corresponding with a fossa (that of the anti-helix) on the opposite aspect. The RETRAiTENS AUREM (musculi rctrahcntes, Alb., fig. 1, ") consists of two or three roundish but separate bundles of fibres, which are stronger than those of the other muscles. The bundles arise from the root of the mastoid process, and pass almost transversely forwards to be inserted by aponeurotic fibres into the lower part of the ear (concha) at its cranial aspect. The posterior auricular artery and nerve are in contact with this muscle. Action. The three preceding muscles will move the outer ear slightly in the directions indicated by their names : the anterior drawing it upwards and forwards, the middle one upwards, and the posterior backwards. The OCCIPITO-FRONTALIS MUSCLK (fig. 1, ^) covcrs the arch of the skull, and consists of an anterior and a posterior fleshy part, with an intervening tendon. Dissection. On the same side of the head (the left) the occipito-frontalis is to be dissected. To bring this muscle into view, a cut may be made along the middle line of the skull, from tlie root of the nose to the occipital protuberance ; and it may be connected in front with the transverse incision on tlie side of the head. The flap of skin, thus marked out, is to be raised with the subjacent fat from before back; whilst doing this the dissector will meet first with the anterior fleshy part of the muscle, next with a white shining thin aponeurosis, and lastly with tlie posterior fleshy belly towards the lateral aspect of the cranium. Tlie aponeurosis of the muscle is easily taken away with the granular fat superficial to it ; and if the under surface of the flap of integuments presents a white instead of a yel- low appearance, the student may suspect he is removing that aponeurosis. The anterior or frontal part (^) is a thin muscular layer over the os frontis, which is said to take its origin below. Along the line of the eye- brow the fibres are blended with the following muscles, orbicularis palpe- brarum, corrugator supercilii, and pyramidalis nasi ; and tiiey are also fixed to the subjacent bone, viz., to the os nasi internally, and to the outer angular process of the frontal bone externally (Theile). From these at- tachments the fibres are directed upwards to the aponeurosis, and end in it rather below the level of tiie coronal suture. The posterior or occipital part (*) is stronger than the anterior ; it arises from the outer half or two-thirds of the upper curved line of the occipital bone, and from the mastoid portion of the temporal bone. The fibres are about one inch and a half in length, and ascend to the aponeurosis. The tendon^ or epicranial aponeurosis^ extends over the upper part of OCCIPITO-FRONTALIS MUSCLE. 19 the cranium, and is continuous across the middle line with the same struc- ture of the opposite half of the head. On the side it gives origin to the jiuricular muscles ; and a thin membrane is here prolonged from it over the fascia covering the temporal muscle, to be fixed to the side of the head. 15. Attollens atirem. 16. Attraheas aureni. Extrinsic Mcsci.es op the Ear. 17. Retrahens aurem, only partly seen. Posteriorly, the aponeurosis is attached to the superior curved ridge of the occipital bone between the fleshy parts of the muscles of opposite sides. Tiie aponeurotic expansion is closely united to the skin ; but it is connected to the pericranium only by a loose areolar tissue devoid of fat, so that it moves freely over the skull. Superficial to the occipito-frontalis are the cutaneous vessels and nerves of the scalp. In front the fleshy fibres of opposite sides are joined above tlie root of the nose. Action, When the anterior belly contracts it elevates the eyebrow, making smooth the skin at the root of the nose, and wrinkling transversely that of the forehead ; and continuing to contract, it draws forward the scalp. The posterior belly will move back the scalp ; and the bellies acting in succession will carry tlie hairy scalp forwards and backwards. Dissection. After the removal of the superior auricular muscles and the temporal vessels, together with the epicranial aponeurosis and its lateral prolongation, the attachment of the temporal fascia on the side of the head may be seen. The temporal fascia is a white, shining membrane, which is stronger tiian the epicranial aponeurosis, and gives attachment to the subjacent temporal muscle. Superiorly it is inserted into the curved line that limits the temporal fossa on the side of the skull ; and inferiorly, where it is nar- rower and thicker, it is fixed to the zygomatic arch. By its cutaneous 20 DISSECTION OF THE HEAD. surface the fascia is in contact with the muscles already examined, and with the superficial temporal vessels and nerves. An incision in the fascia, a little above the zygoma, will show it to con- sist there of two layers, whicli are fixed to the edges of the upper border of the zygomatic arch. Between the layers is some fatty tissue, with a small branch of the superficial temporal artery, and a slender twig of the orbital branch of the superior maxillary nerve with its artery. Dissection. The temporal fascia is now to be detached from the skull, and to be thrown down to the zygomatic arch, in order that the origin of the underlying temporal muscle may be examined. A soft areolar tissue which lies beneath it near the zygoma is to be taken away. The difference in thickness of parts of the fascia will be evident. The TEMPORAL MUSCLE is laid bare only in part. Wide and thin above, it becomes narrower and thicker at the lower end. The muscle arises from the temporal fascia, and from all the surface of the impression on the side of the skull, which is named the temporal fossa. From this origin tlie fibres descend, converging to a tendon, whicli is inserted into the under surface and fore part of the coronoid process of the lower jaw. On the cutaneous surface is the temporal fascia, with tiie parts superfi- cial to that membrane ; and concealed by the muscle are the deep tempo- ral vessels and nerves which ramify in it. The insertion of the muscle underneath the zygomatic arch will be afterwards followed. The temporal belongs to the group of masticatory muscles ; and its action will be referred to with the description of the pterygoid region. Dissection. For the dissection of the vessels and nerves, let the face be now turned to the left side, and let an incision be carried along the eyebrow and the zygomatic arch to a little behind the ear, so as to allow the skin on the right half of the head to be reflected. The flap of skin is to be raised from before backwards, but the subcutaneous fat should be left till the nerves are found. Behind the ear the skin should be raised as on the other side, to un- cover the posterior auricular vessels and nerve. Along the eyebrow seek the branches of vessels and nerves which come from the orbit (fig. 2), viz., the supra-orbital vessels and nerve opposite the middle, and the supra-trochlear nerve and frontal vessels near the inner part of the orbit ; they lie at first beneath the occipito-frontalis, and the muscular fibres must be cut through to find them. On the side of the head, in front of the ear, the superficial temporal vessels and nerve are to be traced to the vertex ; and above the zygomatic arch the branches of the facial which join an offset (^*') of the superior maxillary nerve, are to be sought. Behind the ear the posterior auricular vessels and nerve, and below it branches from the great auricular nerve to the tip and back of tiie ear, are to be found ; one or more offsets of the last should be followed to their junction with the posterior auricular nerve. At the back of the head the ramifications of the occipital vessels, also the large and small occipital nerves, should be denuded ; the former nerve lies by the side of tlie artery, and the latter about midway between this vessel and the ear. Cutaneous Arteries. The arteries of the scalp (fig. 2), are fur- nished by the internal and external carotid trunks, and anastomose freely over the side of the head. Only two small branches, the supra-orbital CUTANEOUS NERVES. 21 and frontal, come from the former ; whilst three, viz., the temporal, occi- pital, and posterior auricular, belong to the latter. The supra-orbital artery (c) leaves the orbit throucrh the notch in the margin of the orbit, and is distributed on the forehead. Some of its branches are superficial to the occipito-frontalis, and ascend to the top of the head ; whilst others lie beneath the muscle, and supply it, the peri- cranium, and the bone. The frontal branch (b) is close to the inner angle of the orbit, and is much smaller than tlie preceding. It ends in branches for the supply of the muscles, integuments, and pericranium. The superficial temporal artery {d) is one of the terminal branches of the external carotid. After ascending above the zygomatic arch for about two inches, the vessel divides on the temporal fascia into anterior and posterior : — The anterior branch runs forwards with a serpentine course to the fore- head, supplying muscular, cutaneous, and pericranial offsets, and anasto- moses with the supra-orbital artery : this is the branch that is opened when blood is taken from the temporal artery. The posterior branch is larger than the other, and arches backwards above the ear towards the occipital artery, with which it anastomoses. Its offsets to the parts around are similar to those of the anterior, and it communicates with the artery of the opposite side over the top of the liead. Occipital artery (a). The terminal part of this artery, after perforat- ing the trapezius, divides into large and tortuous branches, which spread over the back of the head and the occipito-frontalis muscle. Communi- cations take place with the artery of the opposite side, with the posterior part of the temporal, and with the following artery. Some offsets pass deeply to supply the occipito-frontalis muscle, the pericranium, and the bone. The posterior auricular artery ( f) appears in front of the mastoid I)rocess, and divides into two branches. One (mastoid) is directed back- wards to supply the occipito-frontalis, and anastomose with the occipital artery. The other (auricular) is furnished to the retrahent muscle and tlie back of the pinna of the ear ; and an offset from this pierces the pinna to be distributed on the opposite surface. The VEINS of the exterior of the head are so similar to the arteries, that a full notice of each is not required. All the veins corresponding with branches of the internal carotid artery enter the facial vein, whilst the rest open into the jugular veins. These superficial veins communi- cate both with the sinuses in the interior of the skull by means of small branches named emissary, and with the veins occupying the spongy sub- stance (diploe) of the cranial bones. 'The frontal vein is directed towards the inner angle of the orbit, where it receives the supra-orbital vein, the two giving rise to the angular vein of the face : near its ending it receives small veins from the eyebrow, and from the upper eyelid and the nose. Both the superficial temporal and posterior auricular veins open into the external jugular; and the occipital joins the internal jugular vein. Cutaneous Nerves (fig. 2). The nerves of the scalp are furnished from cutaneous offsets of both cranial and spinal nerves. The half of the head anterior to the ear receives branches from three trunks Oi" the fifth cranial nerve, and a few twigs from the facial nerve. All the rest of the 22 DISSECTION OF THE HEAD. head is supplied by spinal nerves (anterior and posterior primary branches), except close behind the ear, where there is an offset of the I'acial or seventh cranial nerve. The stipra-orhital nerve (fig. 2, *) comes from the first trunk of the fifth nerve, and escapes from tlie orbit with its companion artery ; whilst Fig. 2. COTAUEOUS Nerves of the Scalp. 5. Supra-trochlear. 1. Great auricular nerve. 2. Small occipital. .3. Great occipital. 4, I'osteiior auricular of the facial. Auriculo-temporal (not nuniberod) in front of the ear, by the side of the temporal ar- tery, d. Cutaneous Arteries of the Scalp. d. Superficial temporal 6. Supra-orbital. 10. Superficial temporal of the upper maxil- lary, and crossing it are the superficial temporal brandies of the temporal nerve. n. Occipital artery, h. Frontal. c. Supra-orbital. /. Posterior auricular. h. Lateral superficial temporal. beneath the occipito-frontalis muscle, the nerve gives offsets to it and tlie orbicularis palpebrarum, as well as to the pericranium. In the orbicularis CUTANEOUS NERVES. 23 a communication is established between this and the facial nerve. Fi- nally the nerve ends in two cutaneous branches, which ramify in the tegu- ments : — One of these (inner) soon pierces the occipito-fron talis, and reaches upwards as high as the parietal bone. The other branch (outer) is of larger size, and, perforating the muscle higher up, extends over the arch of the head as far as the ear. As the nerve escapes from the supra-orbital notch it furnishes some palpebral filaments to the upper eyelid. At the inner angle of the orbit is the small supra-trochlear branch (fig. 2, ^) of the same nerve. It ascends to the forehead close to the bone, and piercing the muscular fibres ends in the integument. Branches are given from it to the orbicularis and corrugp.tor supercilii, and some palpebral twigs enter the eyelid. The superficial temporal nerves are derived from the second and third trunks of the fifth nerve, and from the facial nerve. The temporal branch of the superior maxillary nerve (second trunk of the fifth) is usually a slender twig (fig. 2, ^®), which perforates the tempo- ral aponeurosis about a finger's breadth above the zygomatic arch. When cutaneous, the nerve is distributed on the temple, and communicates with the facial nerve, also sometimes with the next. The auricula-temporal branch (fig. 2 d) of the inferior maxillary nerve (third trunk of tlie fifth) lies near the ear, and accompanies the temporal artery to the top of the head. As soon as the nerve emerges from beneath the parotid gland, it divides into two terminal branches : — The more pos- terior is the smaller of the two, and supplies the attrahens aurem muscle and the integument above the ear. The other branch ascends vertically in the teguments to the top of the head. The nerve also furnishes an auricular branch (upper) to the anterior part of the ear above the audi- tory meatus. The temporal branches of the facial nerve are directed upwards over the zygomatic arch and the temporal aponeurosis to the orbicularis palpe- brarum muscle : they will be described with the dissection of the trunk of the facial nerve. The posterior auricular nerve (fig. 2, *) lies behind the ear with th(; artery of tlie same name. It arises from the facial nerve close to the stylo-mastoid foramen, and ascends in front of the mastoid process. Soon after the nerve becomes superficial it comm^unicates with the great auri- cular nerve, and divides into an occipital and an auricular branch, which are distributed as their names express : — The occipital branch is long and slender, and ends in the posterior belly of the occipito-fron talis muscle. It lies near the occipital bone, enveloped in dense fibrous structure, and furnishes ofl^'sets to the integu- ments. The auricular branch ascends to the back of the ear, supplying the retrahent muscle and tlie posterior surface of the pinna. The great auricular nerve of the cervical plexus (fig. 2, ^) is seen to some extent at the lower part of the ear, but its anatomy will be after- wards given with the description of the cervical plexus. The great occipital (fig. 2, ^) is the largest cutaneous nerve at the back of the head, and is recognized by its proximity to tlie occipital artery. Springing from the posterior primary branch of the second cervical nerve, it perforates the muscles of the back of the neck, and divides on the occi- 24 DISSECTION OF THE HEAD. put into numerous large offsets ; these spread over the posterior part of the occipito-frontalis muscle, ending mostly in the integument. As soon as the nerve pierces the trapezius, it is joined by an offset from the third cervical nerve ; and on the back of the head it communicates with the small occipital nerve. The small occipital nerve of the cervical plexus (fig. 2, '^) lies midway between the ear and the preceding nerve, and is continued upwards in the integuments higher than the level of the ear. It communicates with the nerve on each side, viz., the posterior auricular and the great occipital. Usually this nerve furnishes an auricular branch to the upper part of the ear at the cranial aspect, which supplies also the attoUens aurem muscle. Section II. INTERNAL PARTS OF THE HEAD. Dissection. The skull is now to be opened, but before sawing the bone the dissector should detach, on the right side, the temporal muscle nearly down to the zygoma, without separating the fascia of the same name from the fleshy fibres ; and all the remaining soft parts are to be divided by an incision carried around the skull, about one inch above the margin of the orbit at the forehead, and as low as the protuberance of the occiput. The cranium is to be sawn in the same line as the incision through the soft parts, but the saw is to cut only through the outer osseous plate. The inner plate is to be broken through with a chisel, in order that tlie subja- cent membrane of the brain (dura mater) may not be injured. The skull- cap is next to be forcibly detached by inserting the fingers between the cut surfaces in front, and the dura mater will then come into view. The DURA MATER is the most external of the membranes investing the brain. It is a strong, fibrous structure, which serves as an endosteum to the bones, and supports the cerebral mass. Its outer surface is rough, and presents, now the bone is separated from it, numerous small fibrous and vascular processes ; but these are most marked along the line of the sutures, where the attachment of the dura mater to the bone is the most intimate. Ramifying on the upper part of the membrane are branches of the large meningeal vessels. Small granular bodies, glands of Pacchioni, are also seen along the middle line. The number of these bodies is very variable ; they are found but seldom before the third year, but generally after the seventh, and they increase with age. Occasionally the surface of the skull is indented by these so-called glands. Dissection. For the purpose of seeing the interior of the dura mater, divide this membrane with a scissors close to the margin of the skull, except in the middle line before and behind where tlie superior longitudi- nal sinus lies. The cut membrane is then to be raised towards the top of the head ; and on the right side the veins connecting it with the brain may be broken through. The inner surface of the dura mater is smooth and polished ; and this appearance is due to an epithelial layer similar to that lining serous membranes. REMOVAL OF BRAIN. 25 This external envelope of the brain consists of white fibrous and elastic tissues so disposed as to give rise to two strata, viz., an external or en- dosteal, and an internal or supporting. At certain spots those layers are slightly separated, and form thereby the spaces or sinuses for the passage of the venous blood. Moreover, the innermost layer sends processes be- tween different parts of the brain, forming the falx, tentorium, etc. The falx cerebri is the process of the dura mater, in shape like a sickle, which dips in the middle line between the hemispheres of the large brain. Its form and extent will be evident if the right half of the brain is gently separated from it. Narrow and pointed in front, where it is attached to the crista galli of the ethmoid bone, it widens posteriorly, and joins a horizontal piece of the dura mater named the tentorium cerebelli. The upper border is convex, and is fixed to the middle line of the skull as far backwards as the occipital protuberance ; and the lower or free border, concave, is turned towards the central part of the brain (corpus callosum), with which it is in contact posteriorly. In this fold of the dura mater are contained the following sinuses : — the superior longitudinal along the convex border, the inferior longitudinal in the hinder part of the lower edge, and the straight sinus at the line of junction between it and the tentorium. The superior longitudinal sinus (fig. 3, 5) extends from the ethmoid bone to the occipital protuberance. Its position in the convex border of the falx will be made manifest by the escape of blood through numerous small veins, when pressure is made from before back with the finger along the middle line of the brain. When the sinus is opened it is seen to be narrow in front, and to widen behind, where it ends in a common point of union of certain sinuses (tor- cular Herophili) at the centre of the occipital bone. Its cavity is trian- gular in form, with the apex of the space turned to the falx ; and across it are stretched small tendinous cords — chordae Willisii — near the openings of some of the cerebral veins. Occasionally small glandulae Pacchioni are present in the sinus. The sinus receives small veins from the substance and exterior of the skull, and larger ones from the brain ; and the blood flows backw^ards in it. The cerebral veins open chiefly at the posterior part of the brain, and lie for some distance against the w^all of the sinus before they perforate the dura mater ; tlieir course is directed from behind forwards, so that the current of the blood in them is evidently opposed to that in the sinus : this disposition of the veins may be seen on the left side of the brain, where the parts are undisturbed. Directions. Before tlie rest of the dura mater can be examined, the brain must be taken from the head. To facilitate its removal, let the head incline backwards, whilst the shoulders are raised on a block, so that the brain may be separated somewhat from the base of the skull. For the division of the cranial nerves a sharp scalpel will be necessary ; and the nerves are to be cut longer on the one side than on the other. Removal of the brain. As a first step cut across the anterior part of the falx cerebri, and the different cerebral veins entering the longitudinal sinus ; raise and throw backwards the falx, but leave it uncut in the middle line behind. Gently raise with the fingers the frontal lobes and the olfactory bulbs of the large brain. Next cut through the internal car- otid artery and the second and third nerves, wiiich then appear; the large second nerve is placed on the inner, and the round third nerve on the 26 DISSECTION OF THE HEAD. outer side of the artery. A small branch of artery to the orbit sliould likewise be divided at this time. Tlie brain is now to be supported in the left hand, and the pituitary body to be dislodged wMtii the knife from the hollow in the centre of the sphe- noid bone. A strong horizontal process of the dura mater (tentorium cere- belli) comes into view at the back of the cranium. Along its free margin lies the small fourth nerve, wiiich is to be cut at this stage of the proceed- ing. Make an incision through the tentorium on each side, close to its attachment to the temporal bone, without injuring the parts underneath ; the following nerves, which will be then visible, are to be divided in suc- cession. Near the inner margin of the tentorium is the fifth nerve, consist- ing of a large and small root; whilst towards the middle line of the skull is the long slender sixth nerve. Below the fifth, and somewhat external to it, is the seventh nerve with its facial and auditory parts, the former being anterior and the smaller of the two. Directly below the seventh are the three trunks of the eighth nerve in one line : — of these, the upper small piece is the glosso- pharyngeal ; the flat band next below, the pneu- mogastric ; and the long round nerve ascending from the spinal canal, the spinal accessory. The remaining nerve nearer the middle line is the ninth, which consists of two small pieces. After dividing the nerves, cut through the vertebral arteries as they wind round the upper part of the spinal cord. Lastly, cut across the spinal cord as low as possible, as well as the roots of the spinal nerves that are attached on each side. Then on placing the first two fingers of the right hand in the spinal canal, the cord may be raised, and the whole brain may be taken readily from the skull in the left hand. Preservation of the hrain. After removing some of the membranes from the upper part, and making a few apertures through them on the under surface, the brain may be immersed in spirit to harden the texture ; and methylated spirit may be used on account of its cheapness. Placing the brain upside down on a piece of calico long enough to Avrap over it, put it in the spirit. Examination of the hrain. At the end of two or three days the dissec- tor should examine the other membranes, and the vessels. As soon as the vessels have been learnt, the membranes are to be carefully removed from the surface of tiie brain, without detaching the different cranial nerves at the under surface. The brain may remain in the spirit till the dissection of the head and neck has been completed, but it should be turned over occasionally to allow the spirit to penetrate its substance. The description of the brain and its vessels will be found after that of the head and neck. Directions. After setting aside the brain, the anatomy of the dura mater, and tlie vessels and nerves in the base of the skull should be proceeded with. For this purpose raise the head to a convenient height, and fasten the tentorium in its natural position with a few stitches. The dissector should be furnished with the base of a skull while studying the following parts. Dura mater. At the base of the cranium the dura mater is much more closely united to the bones than it is at the top of the skull. Here it dips into the different inequalities of the osseous surfaces ; and it sends processes througli the several foramina, wliich join for the most part the pericra- nium, and furnish sheatlis to tlie nerves. Beginning the examination in front, the membrane will be found to send SINUSES OF CRANIUM. 27 a prolongation into the foramen caecum, as well as a series of tubes tlirougli the a[)ertures in tlie cribriform plate of the ethmoid bone. Througli the sphenoidal fissure it joins the periosteum of the orbit ; and through the oi)tic foramen a covering is continued on the optic nerve to the eyeball. Behind the sella Turcica, the dura mater adheres closely to the basilar process of the occipital bone ; and it may be traced into the spinal canal through the foramen magnum, to the margin of which it is very firmly united. The tentorium cerehelli is the piece of the dura mater which is interposed in a somewhat horizontal position between the small brain (cerebellum), and the posterior part of the large brain (cerebrum). Its upper surface is i-aised along the middle, where it is joined by the falx cerebri, and is hollowed laterally for the reception of the back part of the cerebral hemispheres. Its under surface touches the little brain, and is joined by the falx cerebelli. The anterior concave margin is free, except at the ends where it is fixed by a narrow slip to each anterior clinoid process. The posterior or con- vex part is connected to the following bones : — occipital (transverse groove), inferior angle of the parietal, petrous portion of the temporal (upper border), and posterior clinoid process of the sphenoid. Along the centre of the tentorium is the straight sinus; and in the at- tached edge are the lateral and the superior petrosal sinus on each side. Falx cerebri. The characters of this fold have been given in page 25. The Falx cerehelli has the same position below the tentorium as the falx cerebri above that fold. It is much smaller than the falx of the cerebrum, and will appear on detaching the tentorium. Triangular in form, this fold is adherent to the middle ridge of the occipital bone below the pro- tuberance, and projects between the hemispheres of the small brain. Its base is directed to the tentorium ; and the apex reaches the foramen mag- num, to each side of which it gives a small slip. In it is contained the occipital sinus. The SINUSES are venous spaces between the layers of the dura mater, into which blood is received. All the sinuses open either into a large space named torcular Herophili, opposite the occipital protuberance; or into the two cavernous sinuses on the sides of the body of the sphenoid bone. A. The TORCULAR Herophili (fig. 3, a) is placed in the tentorium, opposite the centre of the occipital bone. It is of an irregular shape, and numerous sinuses open into it, viz., the superior longitudinal above, and the occipital below ; the straight in front, and the lateral sinus on each side. The superior longitudinal sinus has been already described (see p. 25). The inferior longitudinal sinus (fig. 3, c) resembles a small vein, and is contained in the lower border of the falx cerebri at the posterior part. This vein receives blood from the falx and the larger brain, and ends in the straight sinus {d) at the edge of tlie tentorium. The straight sinus (fig. 3, d) lies along the middle of the tentorium, and seems to continue the [)receding sinus to the common point of union. Its form is triangular, like the superior longitudinal. Joining it are the inferior longitudinal sinus, the veins of Galen from the interior of the large brain, and some small veins from the upper part of the cerebellum. The occipital sinus (fig. 3, g^ is a small space in the falx cerebelli, which reaches to the foramen magnum, and collects the blood from the occipital fossie. This sinus may be double. 28 DISSECTION OF THE HEAD. The lateral sinus (fig. 3, e) is the channel by which most of the blood passes from the skull. There is one on each side, right and left, which extends from the occipital protuberance to the foramen jugulare, where it ends in the internal jugular vein. In this extent tiie sinus occupies the winding groove in the interior of the skull between the two points of bone before mentioned : and the right is frequently larger than the left. Fig. 3. a. Torcular Herophili. h. Superior loQKUudinal sinus. c. Inferior longitudinal. d. Straight sinus. e. Lateral sinus. g. Occipital sinus. /. Superior, and h, inferior petrosal sinus. SOMK OF THE SiNUSES OP THE SkULL. Besides small veins from the brain, it is joined by the superior petrosal sinus (/), opposite the upper edge of the petrous portion of the temporal bone ; and by the inferior petrosal (h) at tlie foramen jugulare. Often- times it communicates with the occipital vein through the mastoid fora- men, and sometimes with veins of the diploe of the skull. The foramen jugulare is divided into three compartments by bands of the dura mater. Through the posterior interval the lateral sinus passes ; through the anterior the inferior petrosal sinus ; and through the central one the pieces of the eighth nerve. Dissection. To examine the cavernous sinus on the left side, cut through the dura mater by the side of the body of the sphenoid bone from the anterior to the posterior clinoid process, and internal to the position of the third nerve : behind the clinoid process, let the knife be directed in- wards for about half the width of the basilar part of tlie occipital bone. By placing the handle of the scalpel in the opening thus made, the extent of the space will be defined. A probe or a blow-pipe will be required, in order that it may be passed into the different sinuses joining the cavernous centre. B. The CAVERNOUS sinus, which has been so named from the reticu- late structure in its interior, is situate on the side of the body of the sphenoid bone. This space, resulting from the separation of the two layers of th(i dura mater, is of an irregular shape, and extends from the sphenoidal fissure to the tip of the petrous portion of the temporal bone. The piece of dura mater bounding the sinus externally is of some tliick- ness, and contains in its substance the third and fourtli nerves, with the ophthalmic trunk of the fifth nerve ; these lie in their numerical order from above down. The cavity of the sinus is larger behind than before, and in it are shreds of fibrous tissue with small vessels. Tiirough the space winds the MENINGEAL ARTERIES. 29 trunk of the internal carotid artery surrounded by the sympathetic, with the sixth nerve on the outer side of" the vessel ; but all these are shut out from the blood in tlie space by a thin lining membrane. The cavernous sinus receives the ophthalmic vein of the orbit, some inferior cerebral veins, and twigs from tlie pterygoid veins outside the skulL It communicates with its fellow on the opposite side by the circular and transverse sinuses ; and its blood is transmiited to the lateral sinus by the superior and inferior petrosal channels. The circular sinus lies around the pituitary body, and reaches from the one cavernous sinus to the other across the middle line. Besides serving as the means of communication between those sinuses, it receives small veins from the pituitary body. This sinus is usually destroyed by tlie removal of the pituitary body. Tlie transverse or basilar sinus crosses the basilar process of the occipi- tal bone, on a level with the petrous part of the temporal bone, and unites the opposite cavernous sinuses. A second transverse sinus is sometimes found nearer the foramen magnum. The superior petrosal siiius (fig. 3,/) lies in a groove in the upper edge of the petrous part of the temporal bone, and extends between the cavernous and lateral sinuses. A small vein from the cerebellum, and an- other from the internal ear, are received into it. The inferior petrosal sinus (fig. 3, h) extends between the same sinuses as the preceding, and lies in a groove along the line of junction of the petrous part of the temporal with the basilar process of the occipital bone; it is joined by a small vein from the outside of the skull, through the fora- men lacerum in the base of the cranium. This sinus passes through the anterior compartment of the jugular foramen, and ends in the internal jugular vein. Meningeal Arteries. These arteries supplying the cranium and the dura mater come through the base of the skull ; they have been named from their situation in the three fossae, anterior, middle, and posterior meningeal. The anterior meningeal are very small branches of the ethmoidal arteries (p. 56), which enter the skull by apertures between the frontal and eth- moid bones ; they are distributed to the dura mater over and near the ethmoid bone. The middle meningeal arteries are three in number : two, named large and small, are derived from the internal maxillary trunk ; and the third is an offset of the ascending pharyngeal artery. a. The large meningeal branch of the internal maxillary artery appears through the foramen spinosum of the sphenoid bone, and ascends towards the anterior inferior angle of the parietal bone. At this spot the vessel enters a deep groove in the cranium, and ends in ramifications which spread over the side of the head, some of them reaching to the top and the occiput, whilst others perforate the bone, and end on the exterior of the head. Two veins accompany the artery. Branches. As soon as the artery comes into the cranial cavity, it furnishes branches to the dura mater and osseous structure, and to the ganglion of the fifth nerve. One small offset, petrosal, enters the hiatus Fallopii, and supplies the surrounding bone (Hyrtl;. One or two branches pass into the orbit, and anastomose with the ophthalmic artery. 6. The small meningeal branch is an offset of the large one outside the 30 DISSECTION OF THE HEAD. skull, and is transmitted through the foramen ovale to the membrane lining the middle cranial fossa. c. Another meningeal branch from the ascending pharyngeal artery comes through the foramen lacerum (basis cranii). This is seldom in- jected, and is not often visible. The posterior meningeal branches are small, and are furnished by the occipital and vertebral arteries. That from the occipital, one on each side, enters the skull by the jugu- lar foramen ; and that from the vertebral arises opposite the foramen mag- num. Both vessels ramify in the posterior fossa of the skull. Meningeal Nerves. Offsets to the dura mater are said to be derived from the fourth, fifth, glosso-pharyngeal, and vagus, cranial nerves, and from the sympathetic nerve. To make these nerves apparent, it would be necessary to steep the dura mater in diluted nitric acid. Cranial Nerves (fig. 4). The cranial nerves pass from the encepha- lon through apertures in the base of the skull. As each leaves the cranium it is invested by processes of the membranes of the brain, which are thus disposed : — those of the dura mater and pia mater are lost on the nerve ; whilst that of the arachnoid membrane is reflected back, after a short dis- tance, to the interior of the skull. Some of the nerves, those in the middle fossa of the skull for instance, receive sheaths of the dura mater before they approach the foramina of transmission. The nerves will be referred to now as nine pairs, but notice will be subsequently taken of a different mode of enumerating them. Only part of the course of each nerve will be seen at this stage, the rest will be learnt in the dissection of the base of the brain. The FIRST NERVE (fig. 33) ends anteriorly in the enlargement of the olfactory bulb. This swelling lies on the cribriform plate of the ethmoid bone, and supplies about twenty branches to the nose through the small foramina in the subjacent bone. These delicate nerves are surrounded by prolongations of the membranes of the brain, and their arrangement will be noticed in the dissection of the nose. The SECOND NERVE (fig. 4, ^) diverging from its commissure to the eye- ball, enters the orbit through the optic foramen ; accompanying the nerve is the ophthalmic artery. Dissection, The third and fourth nerves, and the ophthalmic trunk of the fifth nerve, lie in the outer wall of the cavernous sinus ; and to see them, it will be necessary to trace them through the dura mater towards the orbit. Afterwards the student should follow outwards the roots of the fifth nerve into the middle fossa of the skull, as in fig. 4, taking away the dura mater from them, and from the surface of the large Gasserian ganglion which lies on the point of the petrous portion of the temporal bone. From the front of the ganglion arise other two large trunks besides the ophthalmic, viz., superior and inferior maxillary, and these should also be traced to their apertures of exit from the skull. If the dura mater is removed en- tirely from the bone near the nerves a better dissection will be obtained. The THIRD NERVE (fig. 4, ^) is destined for the muscles of the orbit. It enters the wall of the cavernous sinus near the anterior clinoid process, and is deprived at that spot of its tube of arachnoid membrane. In the wall of the sinus it is placed above the other nerves ; but when it is about to enter the orbit through the sphenoidal fissure, it sinks below the fourth and a part of the fifth, and divides into two branches. NERVES IN BASE OF SKULL, 31 Near the orbit the nerve is joined by one or two delicate filaments of the cavernous plexus (p. 33). The FOURTH nerve (fig. 4, *) courses forwards, like the preceding, to one muscle in the orbit. It is the smallest of the nerves in the wall of the sinus, and is placed below the third ; but as it is about to pass through the s[)henoidal fissure it rises higher than all the other nerves. Fig. 4. The dura mater has been remoyed iu the middle fossa, on the left side, to show the nerves in the wall of the cavernous sinus, and especially the ganglion, and the three trunks of the fifth nerve. Each nerve, except the first which is absent, is marked by its corresponding numeral. On the right side the dura mater is untouched, t Offsets to the dura mater from the fifth nerve. Cranial Nerves in the Base of the Skull. In the wall of the sinus the fourth nerve is joined by twigs of the sym- pathetic ; and it is sometimes united with the ophthalmic trunk of the fifth. Fifth Nerve (fig. 4, ^). This nerve is distributed to the face and head, and consists of two parts or roots — a large or sensory, and a small or motory. The large root of the nerve passes through an aperture in the dura mater into the middle fossa of the base of the skull, where it ends imme- diately in the Gasserian ganglion. The ganglion of the root of the fifth nerve (Gasserian ganglion), placed in a depression on the point of the petrous part of the temporal bone, is flattened, and is nearly as wide as the thumb-nail. The upper surface of the ganglion is closely united to the dura mater, and presents a semilunar elevation, wliose convexity looks forwards. Some filaments from the plexus of the sympathetic on the carotid artery join its inner side. Branches. From the front of the ganglion proceed the three following trunks: — The ophthalmic nerve, the first and highest, is destined for the orbit and forehead. Next in order is the su))erior maxillary nerve, which leaves the skull by the foramen rotundum, and ends in the face below the 32 DISSECTION OF THE HEAD. orbit. And the last, or the inferior maxillary nerve, passes through the fora- men ovale to reach the lower jaw, the lower part of the face, and the tongue. The smaller root, entering the same tube of the dura mater as the large one, passes beneath the ganglion, without communicating with it, and joins only one of the three trunks derived from the ganglion ; if the ganglion be raised, this root will be seen to enter the inferior maxillary nerve. Those branches of the ganglion which are unconnected with the smaller or motor root, viz., the ophthalmic and superior maxillary, are solely nerves of sensibility ; but the inferior maxillary, which is compounded of both roots, is a nerve of sensibility and motion. But the whole of the inferior maxillary nerve has not this double function, for the motor root is mixed almost exclusively with the part which supplies the muscles of the lower jaw ; and it is, therefore, chiefly that small piece of the nerve which pos- sesses a twofold action, and resembles a spinal nerve. The ophthalmic nerve is the only one of the three trunks which needs a more special notice in this stage of the dissection. It is continued through the sphenoidal fissure and the orbit to the forehead. In form it is a flat band, and is contained in the wall of the cavernous sinus below the third and fourth nerves. Near the orbit it divides into three branches (p. 51). In this situation it is joined by filaments of the cavernous plexus of the sympathetic, and gives a small recurrent filament (fig. 4, f) to that part of the dura mater which forms the tentorium cerebelli (Arnold). The SIXTH NERVE (fig. 4, ^) enters the orbit through the sphenoidal fis- sure, and supplies one of the orbital muscles. It pierces the dura mater behind the body of the sphenoid bone, and crosses the space of the caver- nous sinus, instead of lying in the outer wall with the other nerves. In the sinus the nerve is placed close against the outer side of the carotid artery ; and it is joined by one or two large branches of the sym- pathetic nerve surrounding that vessel. Seventh Nerve according to Willis (fig. 4, ^). This cranial nerve consists of two trunks, fascial and auditory, and both enter the meatus auditorius internus. In the bottom of the meatus they separate ; the facial nerve courses through the aqueduct of Fallopius to the face, and the audi- tory nerve is distributed to the internal ear. Eighth Nerve (fig. 4, *). 'Three trunks are combined in the eighth cranial nerve of Willis, viz., glosso- pharyngeal, pneumogastric, and spinal accessory. All three pass through the central compartment of the foramen jugulare, but all are not contained in one tube of the membranes of the brain. The glosso-pharyngeal nerve is external to the other two, being separated from them by the inferior petrosal sinus, and lias distinct sheaths of the dura mater and the arachnoid membrane ; but the pneumo-gastric and spinal accessory nerves are inclosed in the same tube of the dura mater,* only a piece of the arachnoid intervening between them. The NINTH nerve (fig. 4, ^) is the motor nerve of the tongue, and con- sists of two small pieces, which pierce separately the dura mater opposite the anterior condyloid foramen ; these unite after passing through that aperture. Dissection. The dissector may now return to the examination of the trunk of the carotid artery as it winds through the cavernous sinus. On the o[)posite side of the head, viz., that on which the nerves in the wall of the cavernous sinus are untouched, an attempt may be made to find two small plexuses of the sympathetic on the carotid artery, though in an injected body this dissection is scarcely possible. INTERNAL CAROTID ARTERY. 33 One of these (cavernous) is near the root of the anterior clinoid pro- cess ; and to bring it into view it will be necessary to cut off tliat piece of bone, and to dissect out with care the third, fourth, fifth, and sixth nerves, looking for filaments between them and the plexus. Another plexus (carotid), joining the fifth and sixth nerves, surrounds the artery as this enters the sinus. The INTERNAL CAROTID ARTERY appears in the base of the skull at the apex of the petrous part of the temporal bone. In its ascent to the brain the vessel lies in the space of the cavernous sinus, along the side of the body of the sphenoid bone, and makes two remarkable bends, so as to look like the letter S reclined. At first, the artery ascends to the posterior clinoid process ; it is then directed forwards to the root of the anterior process of the same name ; and lastly it turns upwards internal to this last point of bone, perforates the dura mater bounding the sinus, and divides into cerebral arteries at the base of the brain. In this course the artery is enveloped by nerves derived from the sympathetic in the neck. The hrmiches of the artery here are few. In the sinus there are some small arteries (arteriaa receptaculi) for the supply of the dura mater and the bone, the nerves, and the pituitary body ; and at the anterior clinoid process the ophthalmic branch arises. The terminal brandies of the carotid will be seen in the dissection of the base of the brain. Sympathetic Nerve. Around the carotid artery is a prolongation of the sympathetic nerve of the neck, which forms the following plexuses : — The carotid plexus is situate on the outer side of the vessel, at its en- trance into the cavernous sinus, and communicates with the sixth nerve and the Gasserian ganglion. The small cavernous plexus is placed below the bend of the artery which is close to the anterior clinoid process, and is connected with that offset of the upper cervical ganglion which courses along the inner side of the carotid artery. Filaments from the plexus unite with the third, fourth, and ophthalmic nerves. One filament is also furnished to the lenticidar ganglion in the orbit, either separately from, or in conjunction with, the nasal nerve. After forming those plexuses, the nerves surround the trunk of the carotid, and are lost chiefly in the cerebral membrane named pia mater ; but some ascend on the cerebral and ophthalmic branches of that vessel, and one offset is said to enter the eyeball with the central artery of the retina. Petrosal nerves (fig. 34). Beneath the Gasserian ganglion is the large superficial petrosal nerve (fig. 34, 2) entering the hiatus Fallopii to join the facial nerve. Externally to this is occasionally seen another- small petrosal nerve (fig. 34, *) (^external super jiciaV)^ which springs from the sym[)athetic on the middle meningeal artery, and enters the bone to join the facial nerve. A third, the small petrosal nerve (fig. 34, ^), is con- tained in the substance of the temporal bone. The source, and the desti- nation of those three small nerves will be afterwards learnt. It will suffice now for the student to note the two first, and to see that they are kept moist and fit for examination at a future time. Directions. Now the base of the skull has been completed, a preserva- tive fluid or salt should be applied, and the flaps of the teguments should be stitched together over all. 3 34 DISSECTION OF THE FACE. Section III. DISSECTION OF THE FACE. Directions. The left side of the face may be used for learning the mus- cles and vessels, and the right side is to be reserved for the nerves. Position. The previous position of the body for the examination of the base of the skull will require to be changed : — the head is to be lowered, and the side of the face to be dissected is to be placed upwards. Dissection. As a preparatory step, the muscular fibres of the apertures may be made slightly tense by inserting a small quantity of tow or cotton- wool between the eyelids and the eyeball, and between the lips and the teeth. First lay bare the sphincter muscle of the eyelids by a skin-deep circular incision over the margin of the orbit, and by raising the skin of the lids towards the aperture of the eye. Much care must be taken in detaching the skin from tlie thin and oftentimes pale fibres of the orbicular muscle in the lids, else they will be cut away in consequence of the little areolar tissue between the two. Next the integument is to be removed from the side of the face by one incision in front of the ear, from above the zygomatic arch to the angle of the jaw, and then along the base of the jaw to the chin ; and by another cut carried backwards horizontally from the corner of the mouth into the first. The flaps of skin are to be raised from behind forwards, and left adherent along the middle line. On the side of the nose the skin is closely united to the subjacent parts, and must be detached with caution. Around the mouth are many fleshy slips extending both upwards and downwards from the orbicular muscle, but they are all marked so distinctly as to escape injury, with the exception of the small risorius muscle which goes from the corner of the mouth towards the ramus of the lower jaw. While removing the fat from the muscles, each fleshy slip may be made tense with hooks. Tlie facial vessels and their branches will come into view as tlie muscles are cleaned ; but the nerves may be disregarded on this side. In front of the ear is the parotid gland, whose duct is to be preserved ; this is on a level with the meatus auditorius, and pierces the middle of the cheek. Muscles of the Face (fig. 6). The superficial muscles of tlie face are gathered around the apertures of the nose, eye, and mouth. An orbi- cular or sphincter muscle encircles the apertures of the eye and mouth ; and other muscles .are blended with each to enlarge the opening in the centre of the fibres. There are three distinct groups of muscles : one of the eyelids ; another of the nostril ; and a third of the aperture of the mouth. One of the muscles of mastication, viz., the masseter, is seen between the jaws. Muscles of the Nose. These muscles are the following : pyra- midalis nasi, compressor naris, levator alte nasi, dilator naris, and depressor alai nasi. The PYiiAMiDALis NASI (fig. 5, ^) is a small fleshy slip that covers the nasal bone, and is continuous above with the occipito-fron talis muscle. Over the cartilaginous part of the nose its fibres end in an aponeurosis, MUSCLES OF NOSE, 36 which joins that of the compressor naris. Along its inner border is the muscle of the opposite side. Action. Tliis muscle makes tijfht the skin over the nasal cartilages, but renders lax, and sometimes wrinkles transversely the skin towards the root of the nose. Compressor Naris. This muscle (fig. 5, ^) is not well seen till after the examination of tlie following one. Triangular in shape, it arises by its apex from the canine fossa of the u{)per maxillary bone. The fibres are directed inwards, spreading out at the same time, and end in an aponeurosis, which covers the cartilaginous part of the nose, and joins the tendon of the opposite muscle. This muscle is partly concealed by the next — the common elevator of the ala of the nose and the upper lip. Action. It stretches the skin over the cartilaginous part of the nose. The LEVATOR LABii suPERiORis AL^EQUE NASI (fig. 5, ^) is placed by the side of the nose, and arises from the top of the nasal process of the upper maxillary bone, internal to the attachment of the orbicularis. As the fibres descend from the inner part of the orbit the most internal are Fig. 5. 1. Pyramidalis nasi. 2. Common elevator of the nose and lip. 3. Compressor naris. 4 and 5. The two slips of the dilatator naris. 6. Depressor alse nasi. 7. Orbicularis oris, attached to the septum nasi. Muscles of the Nose. attached by a narrow slip to the wing of the nose, whilst tlie rest are blended inferiorly with the orbicularis oris. Near its origin the muscle is partly concealed by the orbicularis palpebrarum, but in the rest of its extent it is subcutaneous. Its outer border joins the elevator of the upper lip. Action. As the name expresses, it can raise the upper lip, and draw outwards the wing of the nose, dilating tlie aperture ; but when the mouth is shut it can enlarge the nostril independently of the lip. Dilatator Naris. In the dense tissue on the outer side of the nostril are a few muscular fibres, both at the fore and back part of that aperture (fig. 5,*, and *), to which the above name has been given by Theile: they are seldom visible without a lens. The anterior slip, *, j asses from the cartilage of the aperture to the integument of the margin of the nostril ; and the posterior^ °, arising from the upper jawbone and the small sesa- moid cartilages, ends also in the integuments of the nostril. 36 DISSECTION OF THE FACE. Action. The fibres enlarge the nasal opening by raising and everting the outer edge. The DEPRESSOR AL^ NASI (fig. 5, *) will be seen if the upper lip is everted, and the mucous membrane is removed from the side of the frtenum of the lip. It arises below the nose from a depression of the upper jaw- bone above the roots of the second incisor and canine teeth ; and ascends to be inserted into the septum nasi and the posterior part of the ala of the nose. Action. By drawing down and turning in the edge of the dilated nostril, it restores the aperture to its usual size. Muscles of the Eyelids. The muscles of the eyelids and eyebrow are four in number, viz., orbicularis palpebrarum, corrugator supercilii, levator palpebrfe superioris, and tensor tarsi :^ the two latter are dissected in the orbit, and will be described with it. The orbicularis palpebrarum (fig. 6, ^) is the sphincter muscle closing the opening between the eyelids. It is a flat and thin layer, which extends from the margin of the lids beyond the circumference of the orbit. From a difference in the characters of the fibres, a division has been made of them into two parts — outer and inner. The external fibres (orbital part), the best marked, are fixed only at one point, viz., the inner angle of the orbit. This attachment (origin) is connected with the surface and borders of the small tendo palpebrarum ; above that tendon with the nasal process of the upper maxillary, and the internal angular process of the frontal bone ; and below the tendon with the superior maxillary bone, and the margin of the orbit. From this origin the fibres are directed outwards, giving rise to ovals, which lie side by side, and increase in size towards the outer edge of the muscle where they project beyond the margin of the orbit. The internal, fibres (palpebral part), paler and finer than the outer, occupy the eyelids, and are fixed at both the outer and inner angles of the orbit. Internally (origin) they are united with the tendo palpebrarum, and externally (insertion) with the external tarsal ligament and the malar bone, and some few may blend with the orbital part. Close to the cilia or eyelashes the fibres form a small pale bundle, which is sometimes called ciliary. The muscle is subcutaneous ; and its circumference is blended above with the occipito-frontalis. Beneath the upper half of the orbicularis, as it lies on the margin of the orbit, is the corrugator supercilii muscle with the supra-orbital vessels and nerve ; and beneath the lower half is part of the elevator of the upper lip. The outer fibres are joined occasionally by slips to other contiguous muscles below the orbit. Action. The inner fibres cause the lids to approach each other, shut- ting tlie eye ; and in forced contraction the outer commissure is drawn inwards. In closure of the eye the lids move unequally — the upper being much depressed, and the lower slightly elevated and moved horizontally inwards. When the outer fibres contract, the eyebrow is depressed, and the skin over the edge of the orbit is raised around the eye, so as to protect the ball. Elevation of the upper lip follows contraction of the outer part of the orbicularis, in consequence of fibres being prolonged to the levator labii superioris. ' The tensor tarsi muscle (p. 59) is sometimes described as a part of the orbicu- laris. MUSCLES OF MOUTH 37 The CORRUGATOR suPKRCiLii IS beneath the orbicularis, near the inner angle of the orbit. Its fibres arise from the inner part of the superciliary ridge of the frontal bone, and are directed outwards to join the orbicular muscle about the middle of the orbital arch. It is a short muscle, and is distinguished by the closeness of its fibres. Action. It draws inwards and downwards the mid-part of the eyebrow, wrinkling vertically the skin near the nose, and stretching that outside its point of insertion. Muscles of the Mouth. The muscles of the aperture of the mouth consist of a S[)hincter ; an elevator of the upper lip and angle of the mouth ; ixn elevator and depressor of the lower lip and angle of the mouth ; and retractors of the corner. Lastly, a wide muscle of the cheek closes the space between the jaws. Fi2:. 6. 1. Occipito-frontalis, anterior belly. 4. Posterior belly. 2. Orbicularis palpebrarum. 3. Levator labii superioris alaeque nasi. 5. Compressor nasi. 6. Levator labii superioris. 7. Zygomaticus minor (too large). 8. Zygomaticus major. 9. Risorius. 10. Masseter. 11. Orbicularis oris. 12. Depressor labii inferioris. \'^. Depressor anguli oris. 14. Buccinator. •f Levator auguli oris. See fig. 1. The ORBICULARIS ORIS MUSCLE (fig. 6, ") suiTOunds the opening of the mouth, and is united \\\i\\ the several muscles acting on that aperture. It consists of two parts, inner and outer, which differ in the appearance and arrangement of the fibres, like the sphincter muscle of the eyelids. The iiiner part (fig. 5, ^), whose fibres are pale in color and fine in texture, forms a rounded thick fasciculus, which corresponds with the red margin of the lip. The fibres of this portion of the muscle, unattached to bone, blend with the buccinator at the corner of the mouth, and some pass from lip to lip. The outer part is thin, wide, and more irregular in form, and is con- nected with the subjacent bone, besides its union with the adjacent muscles. In the upper lip it is attached, on each side of the middle line, by one slip (naso-labial) to the back of the septum of the nose (fig. 5, ^) ; and by a thin stratum to the outer surface of the upper jaw, opposite the canine tooth, and external to the depressor of the wing of the nose. In the 38 DISSECTION OF THE FACE. lower lip it is fixed on each side into the inferior jawhone, opposite the canine tooth, external to the levator lahii inf'erioris musck\ To see these attachments the lip must be everted, and the mucous membrane carefully- raised. The inner margin of the muscle is free, and bounds the aperture of the mouth ; whilst the outer edge blends with the different muscles that ele- vate or depress the lips and the angle of the mouth. Beneath the orbicu- laris in each lip is the coronary artery, with the mucous membrane and the labial glands. Action. Both parts of the muscle contracting, the lips are pressed to- gether and projected forwards, and the aperture of the mouth is diminished transversely by the approximation of the corners towards each other. The inner fibres acting alone will turn inwards the red part of the lip, and diminish the width of the buccal opening. Tiie outer fibres press the lips against the dental arches, the free edges being protruded and somewhat everted. At the same time the centre part of the nose is depressed and the chin raised by means of tlie fleshy slips connected with those parts. The LEVATOR LABii SUPERIORJS (fig. 6, ^) cxteuds vertically from the lower margin of the orbit to the orbicularis oris. It arises from the upper maxillary and malar bones above the infra-orbital foramen, and blends inferiorly with the orbicularis oris. Near the orbit the muscle is overlapped by the orbicularis palpebrarum, but below that spot it is sub- cutaneous. By its inner side it joins the common elevator of the ala of the nose and upper lip ; and to its outer side lie the zygomatic muscles, the small one joining it. Beneath it are the infra-orbital vessels and nerve. Action. By the action of this muscle the upper lip is raised, and the skin of the cheek is bulged below the eye. The DEPRESSOR LABII iNFERiORis (fig. 6, ^'^) is Opposite the elevator of the upper lip, and has much yellow fat mixed with its fibres. The muscle has a wide origin from a depression on the front of the lower jaw, reaching backwards from near the symphysis to a little beyond the hole for the labial vessels and nerve ; ascending thence it is united with the orbicularis in the lower lip. Its inner border joins the muscle of the oppo- site side above, and its outer is overlapped below by the depressor anguli oris. Action. If one muscle contracts, the half of the lip of the same side is depressed and everted ; but by the use of both muscles, tlie whole lip is lowered and turned outwards, and rendered tense at the centre. The LEVATOR LABii INFERIORIS (levator menti) is a small muscle on the side of the frainum of the lower lip, which is opposite the depressor of the ala of the nose in the upper lip. When the lip has been everted and the mucous membrane removed, the muscle will be seen to arise from a fossa near the symphysis of the lower jaw, and to descend to its insertion into the integument of the chin. Its position is internal to the depressor of the lip and the attachment of the orbicularis. Action. It indents the skin of the chin opposite its insertion, and assists in raising the lower lip. The LEVATOR ANGULI ORIS (fig. G, f) has well-marked fibres, and is partly concealed by the levator labiisuperioris. Arising from the canine fossa beneath the infi-a-orbital foramen, its fibres spread out towards the angle of the mouth where they are superficial to the buccinator, and mix MUSCLES OF MOUTH. 39 with the rest of the muscles, but the greater number are continued into the depressor anguli oris and the lower lip. Action. This muscle elevates the corner of the mouth, and acts as an antagonist to the depressor. The DEPRESSOR ANGULI ORIS (fig. 6, ^*) is triangular in shape ; it arises from the oblique line on the outer surface of the lower jaw, and ascending to the angle of the mouth, its fibres are prolonged into the ele- vator of the angle. The muscle conceals the labial branch of the inferior dental vessels and nerve. At its origin the depressor is united with the platysma myoides, and near its insertion with the risorius muscle. Action. The angle of the mouth is drawn downwards and backwards by it, as is exemplified in a sorrowful countenance. The ZYGOMATIC MUSCLES (fig. 6) are directed obliquely from the arch of the same name towards the angle of the mouth and the upper lip. One is longer and larger than the other ; they are therefore named major and minor. The zygomaticus major ^ ^, arises from the outer part of the malar bone, and is inserted into the angle of the mouth. The zygomaticus misior, ', is attached to the malar bone anterior to the other, and blends with the fibres of the special elevator of the upper lip. Action. The large muscle inclines upwards and backwards the corner of the mouth ; and the small one assists the levator labii superioris in raising the upper lip. The RISORIUS MUSCLE (SantoHni) (fig. 6,^) is a thin and narrow bun- dle of fibres, sometimes divided into two or more parts, which arises externally from the fascia over the masseter muscle, and is connected in- ternally with the apex of the depressor anguli oris. Action. The use of this muscle is indicated by its name, as it retracts the corner of the mouth in laugliing. The BUCCINATOR (fig. 6, ^*) is the flat and thin muscle of the cheek, and occupies the interval between the jaws. The muscle arises from the outer surface of the alveolar borders of the upper and lower maxillie, as far forwards in each as the first molar tooth ; and in the interval between the jaws behind it is attached to a band of fascia — the pterygo-maxillary ligament. From the origin the fibres are directed forwards to the angle of the mouth, where they mix with the other muscles and with both parts of the orbicularis ; and as some of the central fibres descend to the lower lip whilst others ascend to the upper lip, a decussation takes place at the corner of the mouth. On the cutaneous surface of the buccinator are the different muscles converging to the angle of the mouth ; and crossing the upper part is the duct of the parotid gland, which perforates the muscle opposite the second upper molar teeth. Internally the muscle is lined by the mucous membrane of the mouth, and externally it is covered by a fascia (bucco- pliaryngeal) that is continued to the pharynx. By its intermaxillary origin the buccinator corresponds with the attachment of the superior constrictor of the pharynx. Action. By one muscle the corner of the mouth is retracted, and the cheek wrinkled. By the action of both tiie aperture of the mouth is widened transversely. In mastication the cheek is pressed by the muscular contraction against the dental arches, when the corner of the mouth is fixed by the sphincter. In the expulsion of air from the mouth, as in whistling, the muscle is 40 DISSECTION OF THE FACE. contracted so as to prevent bulging of the cheek ; but in the use of a blow-pipe it is distended over the volume of air contained in the mouth, and drives out a continuous stream of air by its contraction. The VESSELS OF THE FACE (fig. 17) are the facial and transverse facial arteries with their accompanying veins. The arteries are branches of the external carotid; and the facial vein is received into the internal jugular trunk. The facial artery (fig. 17, f), a branch of the carotid, emerges from the neck, and appears on the lower jaw anterior to the masseter muscle. From this point the artery ascends in a tortuous manner, near the angle of the mouth and the side of the nose, to the inner angle of the orbit, where it anastomoses with the ophthalmic artery. The course of the ves- sel is comparatively superficial in the mass of i'at of the inner part of the cheek. At first it is concealed by the platysma whilst crossing the jaw, but this thin muscle does not prevent pulsation being recognized during life; and near the mouth the large zygomatic muscle is sui)erficial to it. The vessel rests successively on the lower jaw, buccinator muscle, ele- vator of the angle of the mouth, and elevator of the upper lip. Accom- panying the artery is the facial vein, which is nearly a straight tube, and lies to the outer side. Branches. From the outer side of the vessel unnamed branches are furnished to the muscles and integuments, some of which anastomose with the transverse facial artery. From the inner side are given the following branches : — The inferior labial branch (t) runs inwards beneath the depressor anguli oris muscle, and is distributed between the lower lip and chin; it communicates with the inferior coronary, and with the labial branch of the inferior dental artery. Coronary branches (r and s). There is one for each lip (superior and inferior), which arise together or separately from the facial, and are di- rected inwards between the orbicular muscle and the mucous membrane of the lip, till they inosculate with the corresponding branches of the opposite side. From the arterial arches thus formed, offsets are supplied to the lips and labial glands. From the arch in the upper lip a branch is given to each side of the septum of the nose, — artery of the septum. The lateral nasal branch (p) arises opposite the ala nasi, and passes beneath the levator labii superioris aloeque nasi to the side of the nose, where it anastomoses with the internal nasal branch of the ophthalmic artery. The angular branch (o) is the terminal twig of the f^icial artery at the inner angle of the orbit, and joins with a branch (external nasal) of the ophthalmic artery. The facial vein commences at the root of the nose in a small vein named angular (p. 21). It then crosses over the elevator of the upper lip, and separating from the artery, courses beneath the large zygomatic mus- cle to the side of the jaw. Afterwards it has a short course in the neck to join the internal jugular vein. Branches. At the inner side of the orbit it receives veins from the lower eyelid (inferior palpebral), and from the side of the nose. Below the orbit it is joined by the infra-orbital vein, also by a large branch, anterior internal maxillary, that comes from the pterygoid region; and thence to its termination by veins corresponding with the branches of the artery in the face and neck. PAROTID GLAND. 41 The transverse facial artery (fig. 17) is a branch of the temporal, and appears in the face at the anterior border of tlie parotid gland. It lies by the side of the parotid duct, with branches of the facial nerve, and dis- tributes offsets to the muscles and integuments ; some branches anastomose with the facial artery. Dissection. The parotid gland in front of the ear may be next displayed. To see the gland, raise the skin from the surface towards the ear by means of a cut from the base of the jaw to the anterior border of the sterno-mas- toid muscle ; this cut may be united with that made for the dissection of tlie posterior muscle of the ear. A strong fascia covers the gland, and is connected above and behind to the zygomatic arch and the cartilage of the ear, but is continued over the face in front; this is to be removed, so that the gland may be detached slightly from the parts around. The great auricular nerve will be seen ascending to the lobe of the ear ; and one or two small glands rest on the surface of the parotid. The PAROTID (fig. 16, '^^) is the largest of the salivary glands. It occu- pies the space between the ear and the lower jaw, and is named from its position. Its excretory duct enters the mouth through the middle of the cheek. The shape of the gland is irregular, and is determined somewhat by the bounding parts. Thus inferiorly, where there is not any resisting struc- ture, the parotid projects into the neck, and comes into close proximity with the sub-maxillary gland, though separated from it by a process of the cervical fascia; a line from the angle of the jaw to the sterno-mastoid muscle marks usually the extent of the gland in this direction. Above, the parotid is limited by the zygomatic arch and the temporal bone. Along the posterior part the sterno-mastoid muscle extends; but anteriorly the gland projects somewhat on the face, and in this direction a small accessory part, socia parotidis^ is prolonged from it over the masseter. Connected with the anterior border is the excretory duct — duct of Sten- son (ductus Stenonis, fig. 17), which crosses the masseter below the socia parotidis, and perforates the cheek obliquely opposite the second molar tooth of the upper jaw. The duct lies between the transverse facial artery and some branches of the facial nerve, the latter being below it. A line drawn from the meatus auditorius to a little below the nostril would mark the level of the duct in the face ; and the central point of the line would be opposite the opening into the mouth. The length of the duct is about two inches and a half; and its capacity is large enough to allow a small probe to pass, but the opening into the mouth is much less. The cutaneous surface of the parotid is smooth, and one or two lymphatic glands are seated on it ; but from the deep part processes are sent into the inequalities of the space between the jaw and the mastoid process. Dissection. By removing with caution the parotid gland, the hollows that it fills wnll come into view : at the same time the dissector will see the vessels and nerves that pass through it. An examination of the pro- cesses of the gland, and of the number of important vessels and nerves in relation with it, will demonstrate the dangers attending any operation on it. The duct may be opened, and a pin may be passed along it to the mouth, to show the diminished size of the aperture. Two large processes of the gland extend deeply into the neck. One dips behind the styloid process, and projects beneath the mastoid process and sterno-mastoid muscle, whilst it reaches also tlie deep vessels and nerves of the neck. The other piece is situate in front of the styloid 42 DISSECTION OF THE FACE. process ; it passes into the glenoid hollow behind the articulation of the lower jaw ; and sinks beneath the ramus of" that bone along the internal maxillary artery. Passing through the middle of the gland is the external carotid artery, which ascends behind the ramus of the jaw, and furnishes the auricular, superficial temporal, and internal maxillary branches. Superficial to the artery lies the trunk formed by the junction of the temporal and internal maxillary veins, from which tlie external jugular vein springs ; and this common trunk, receiving some veins from the parotid, is connected with the internal jugular vein by a branch through the gland.^ Crossing the gland from behind forwards is the trunk of the facial nerve, which passes over the artery, and distributes its branches through the parotid. The superficial temporal branch. of the inferior maxillary nerves lies above the upper part of the glandular mass ; and offsets of the great auricular nerve pierce the gland at the lower part, and join the facial. The structure of the parotid resembles that of the other salivary glands. The glandular mass is divided into numerous small lobules by intervening processes of fascia ; and eacli lobule consists of a set of the fine closed sac- cular extremities of the excretory duct, which are lined by flattened and nucleated epithelium, and surrounded by capillary vessels. These little sacs form by their aggregation the mass of eacli lobule. From the lobules issue small ducts, which unite to form larger tubes, and finally all the ducts of the gland are collected into one. The common duct (duct of Stenson) is composed of an external fibrous coat, consisting of white and elastic fibres ; and of an internal mucous coat which is clothed with columnar epithelium. The parotid receives its arteries from the external carotid ; and its nerves from the sympathetic, auriculo-temporal of tlie fifth, facial, and great auri- cular. Its lymphatics join those of the neck. Two or three small molar glands lie along the origin of the buccinator, and open into the moutli near the last molar tooth by separate ducts. Cartilages of the Nose (fig. 7). These close the anterior nasal aperture in the skeleton, and form part of the outer nose and the septum. Tliey are five in number, two on each side — lateral cartilage and cartilage of the aperture ; together with a central one, or the cartilage of the septum of the nose. Only the lateral cartilages are seen in this stage of the dis- section. Dissection. The lateral cartilages will be seen when the muscular and fibrous structure of the left side of the nose, and the skin of the lower part of the nostril of the same side, have been taken away. By turning aside the lateral cartilages the septal one will appear in the middle line. The upper lateral cartilage (fig. 7, ^) is flattened, and is somewhat triangular in form. Posteriorly it is attached to the nasal and upper maxillary bones ; and anteriorly it meets the one of the opposite side for a short distance above, but the two are separated below by an interval, in which the cartilage of the septum appears. Interiorly the lateral cartilage • Oftentimes there is a different arrangement of these veins. In such case the external jugular is continued from the occipital (half or all) and posterior auri- cular veins ; whilst the temporal and internal maxillary veins unite to form a trunk (tempo-maxillarj), which receives the facial below the jaw, and opens into the internal jugular vein opposite the upper Imrder of the thyroid cartihage. When this condition exists, the temporo-maxillary vein accompanies the external carotid artery. APPENDAGES OF EYE. 43 is contiguous to the cartilage of the aperture, and is connected to it by fibrous tissue. The cartilage of the aperture (fig. 7) forms a ring around the opening of the nose except behind. It has not any attacliraent directly to bone ; but it is united above to the lateral cartilage by fibrous tissue, and below with the dense teguments forming the margin of the aperture of the nostril. Fig. 7. 1. Triangular septal cartilage. 2. Upper lateral cartilage. 3. Lower lateral, or the cartilage of the aperture, the outer part. 4'. Inner part of the cartilage of the aperture. 5. Nasal boue. Lateral Cartilages of the Nose. The part of the cartilage (^) which bounds the opening externally, is narrow and pointed behind, wliere it ends in two or three small pieces of cartilage — cartilagines minores vel sesamoidece ; but swells out in front where it touches its fellow, and forms the apex of the nose. Tiie inner part (*) projects backwards along the septum of the nose nearly to the superior maxillary bone ; it assists in the formation of the par- tition between the nostrils, and extends below the level of the septum nasi. The Appendages of the Eye include the eyebrow, the eyelid, and the lachrymal apparatus. Some of these can be examined now on the opposite side of tlie face. The apparatus for the tears will be dissected after the orbit lias been completed. The eyebrow (supercilium) is a curved eminence just above the eye, which is placed over the orbital arch of the frontal bone. It consists of thickened integuments, and its prominence is in part due to the subjacent orbicularis palpebrarum. It is furnished with long coarse hairs, which are directed outwards, and towards one another. The eyelids are two movable semilunar parts in front of the eye, which can be approached or separated over the eyeball. The upper lid is the largest and the most movable, and descends below the middle of the eye- ball when the two meet ; it is also provided with a special muscle to raise it. The interval between the open lids is named Jissura palpebrarum. Externally and internally tliey are united by a commissure or canthns. Tlie free margin is tliicker than the rest of tlie lid, and is semilunar in form ; but towards the inner side, about a quarter of an inch from the commissure, it becomes straighter. At the spot where the two parts join is a small white eminence (fig. 13, ^) the papilla lachrymalis : and in this is the punctum lachrymale, or the opening of tlie canal for the tears. This margin is provided anteriorly with the eyelashes, and near the posterior edge with a row of small ojjenings of the Meibomian glands ; but both the cilia and the glands are absent from the part of the lid which is internal to the opening of the punctum lachrymale. The free margin 44 DISSECTION OF THE FACE. of each lid is sharp at the anterior edge where it touches its fellow ; but is sloped at the posterior, so as to leave an interval between it and the eye- ball for the passage inwards of fluid. The eyelashes (cilia) are two or more rows of curved hairs, which are fixed into the anterior edge of the free border of the lid ; tliey are largest in the upper lid, and diminish in length from the centre towards the sides. Tiie cilia are convex towards one another, and cross when the lids are shut. The Structure of the Eyelids. Each lid consists fundamentally of a piece of cartilage attached to the bone by ligaments. Superficial to this framework are the integuments with a layer of fibres of the orbicularis palpebrarum, and beneath it the mucous lining of the conjunctiva. The upper lid includes also the tendon of the levator palpebras. Vessels and nerves are contained in the lids. Dissection. The student may learn the structure of the lids on the left side, on which the muscles are dissected. The bit of tow or wool may remain beneath the lids; and the palpebral part of the orbicularis muscle is to be thrown inwards by an incision around the margin of the orbit. In raising the muscle care must be taken of the thin membranous palpe- bral ligament beneath, and of the vessels and nerves of the lid. Orbicularis palpebrarum. The palpebral fibres of this muscle form a pale layer which reaches the free edge of the eyelids (p. 36). A thin stratum of areolar tissue without fat unites the muscle with the skin. The palpebral ligame^it is a stratum of fibrous membrane, which is continued from the margin of the orbit to join the lower or free edge of each tarsal cartilage. At the inner part of the orbit the ligament is thin and loose, but at the outer part it is somewhat thicker and stronger. The tarsal cartilages^ one for each eyelid, are elongated transversely, and give strength to the lids. Each is fixed internally by the ligament of the eyelids, and externally by a fibrous band — external tarsal ligament, to the outer part of the orbit. Tiie margin corresponding with the edge of the lid- is free, and thicker than the rest of the cartilage. On the inner surface each cartilage is lined by the mucous membrane or conjunc- tiva. The cartilages are not alike in the two lids. In the upper eyelid, where the cartilage is largest, it is crescentic in shape, and is about half an inch wide in the centre; and to its fore part the tendon of the levator [)al[)ebra3 is attached. In the lower lid the cartilage is a narrow band, about two lines broad, with borders nearly straigiit. Ligament of the eyelids (tendo palpebrarum, internal tarsal ligament) is a small fibrous band at the inner part of the oubit, which serves to fix the lids, and is attached to the anterior margin of the lachrymal groove in the upper jaw. It is about a quarter of an inch long, and divides into two processes, which are united with the tarsal cartilages, one to each. This ligament crosses the lachrymal sac, to which it gives a fibrous expan- sion ; and the fleshy fibres of the orbicularis palpebrarum arise from it. The Meibomian glands or follicles are placed in grooves on the ocular surface of the tarsal cartilages. They extend, parallel to one another, from the thick towards the op[)Osite margin of the cartilage ; and their number is about thirty in the upper, and twenty in the lower lid. The apertures of the glands open in a line on the free border of the lid near the pos- terior edge. Each gland is a small yellowish tube, closed at one end, and having AURICLE OF THE EAR. 45 minute lateral coRcal appendafi;es connected with it. Each contains a seba- ceous secretion, and is lined by flattened epithelium. If the j)alpebral ligament be cut through in the upper lid, the tendon of the levator palpebrce will be seen to be inserted into the fore part of the tarsal cartilage by a wide aponeurotic expansion. The conjunctiva, or the mucous membrane, lines the interior of the eyelids, and covers the anterior part of the ball of the eye. Inside the lids it is inseparably united to the tarsal cartilages, and has numerous fine papilla?. At the free margin of the lid this membrane joins the common integuments. Through the lachrymal canals and sac it is continuous with the pituitary membrane of the nose. At the inner commissure of the eyelids the conjunctiva forms a promi- nent and fleshy-looking body — caruncula lachrymalis (fig. 13, *), which contains a group of mucous follicles, and has a few^ minute hairs on its surface. External to the carimcle is a small vertical fold of the mucous membrane — plica semilunaris ; this extends to the ball of the eye, and represents the membrana nictitans of birds. Bloodvessels of the eyelids. The arteries of the eyelids are furnished by the ophthalmic artery, and come from the palpebral and lachrymal branches : — Tiie palpebral arteries, one for each eyelid, run outw^ards from the inner canthus, lying between the tarsal cartilage and the tendon of the special elevator in the upper lid, and between the cartilage and the palpebral liga- ment in the lower lid ; and they anastomose externally with the lachrymal artery. From the arch that each forms, branches are distributed to the eyelids. T!ie lachrymal artery furnishes an offset to each lid to form arches with the palpebral arteries, and then perforates the palpebral ligament at the outer part of the orbit to end in the upper lid. The veins of the lids open into the frontal and angular veins at the root of the nose (pp. 21, 40). The nerves of the eyelids are supplied from the ophthalmic and facial nerves. The branches of the ophthalmic nerve (of the fifth) which give offsets to the upper lid, are the following : lachrymal, near the outer part ; snpra" orbital, about the middle ; and supra-trochlear and infra-trochlear at the inner side (pp. 42, o4). In the lower eyelid, about its middle, is &. palpe- bral branch of the superior maxillary trunk of the fifth nerve. Branches of the facial nerve (p. 48) enter both lids at the outer part, and supply the orbicularis muscle ; they communicate with the offsets of the fiftli nerve. External Ear. The outer ear consists of a trumpet-shaped structure, named pinna or auricle, which receives the undulations of the air ; and of a tube — meatus auditorius, wiiich conveys them to the inner ear. The pinna may be examined on the left side of the head ; but the anatomy of the meatus will be described with tiie ear. The pinna, or auricle^ is fin uneven piece of yellow fibro-cartilag(s which is covered with integument, and is fixed to the margin of the meatus auditorius externus. It is of an oval form, with the margin folded and the larger end placed upwards. The surface next the head is generally convex ; but the opposite is ex- cavated, and presents the undermentioned elevations and depressions. In the centre is a deep hollow named concha, which is wide above but narrow 46 DISSECTION OF THE FACE. below ; it conducts to the meatus auditorius. In front of the narrowed part of the hollow is a projection of a triangular shape — the tragus, which has some hairs on the under surface ; and on the opposite side of the same narrow end, rather below the level of the tragus, is placed another projec- tion— the antitragus. The round rim-like margin of the ear, which extends into the concha, is called the helix; and the depression internal to it is the groove or fossa of the helix. Within the helix, between it and the concha, is the large Fiff. 8. Muscles on the Outer Surface of the Ear Cartilaoe, 1. Muscle.-! of the tragus. 3. Large muscle of the helix. 2. Muscles of the antitragus. 4. Small muscle of the helix. Muscles on the Inner Surface of the Ear Cartilage 6. Transverse muscle. 7. Oblique muscle (Tod) sometimes seen. eminence of the antihelix, which presents at its upper part a well-marked depression, ihoi fossa of the antihelix. Inferiorly the external ear is terminated by a soft pendulous part, the lobule. The special muscles of the piniia, which ex.tend from one part of the cartilage to another, are very thin and pale. Five small muscles are to be recognized ; and these receive their names for the most part from the several eminences of the external ear. Dissection. In seeking the small auricular muscles, let the integuments be removed only over the spot where each muscle is said to be placed. A siiarp knife and a good light are necessary ibr the display of the muscular fibres. Occasionally the dissector will not tind one or more of the number described below. The muscle of the tragus (fig. 8, ^) is always found on the external aspect of the process from wiiich it takes its name. The fibres are short, oblique, or transverse, and extend from the outer to the inner part of the tragus. The muscle of the antitragus (fig. 8, ^) is the best marked of all. It arises from the outer part of the antitragus, and the fibres are directed U[>wards to be inserted into the pointed extremity of tlie antihelix. The small muscle of the helix (fig. 8, *) is often indistinct or absent. It is placed on the part of the rim of the ear that extends into the concha. Tiie large muscle of the helix (fig. 8, ^) arises above the small muscle CARTILAGE OF AURICLE. 47 of the same part, and is inserted into the front of the helix, where this is about to curve backwards. It is usually present. The transiyerse muscle of the auricle (fig. 8, ^) forms a wide layer, which is situate at the back of the ear in the depression between the helix and the convexity of the concha. It arises from the convexity of the carti- lage forming the concha, and is inserted into the back of the helix. The muscle is mixed with much fibrous tissue, but it is well seen when that tissue is removed. Actions, These muscles are said to alter slightly the condition of the outer ear; the muscles of the helix assisting, and those of the tragus and anti tragus retarding the passage of sonorous undulations to the meatus. Dissection. The pinna may now be detached by cutting it close to the bone. When the integuments are entirely taken off, the cartilage of the pinna will be apparent ; but in removing the integuments, the lobule of the ear, which consists only of skin and fat, will disappear as in fig. 8. The cartilage of the pinna (fig. 8) resembles much the external ear in form, and presents nearly the same parts. The rim of the helix subsides posteriorly in the antihelix about the middle of the pinna ; whilst ante- riorly a small process projects from it, and there is a fissure near the pro- jection. The antihelix is divided about two-thirds down into two pieces ; one of these is pointed, and is joined by the helix, the other is continued into the antitragus. On the posterior aspect of the concha is a strong vertical process of cartilage. Inferiorly the cartilage is fixed to the margin of the external auditory aperture in the temporal bone, and forms part of the meatus auditorius ; but it does not give rise to a complete tube, for at the upper and outer part the canal is closed by fibrous tissue. In the piece of cartilage forming the under part of the meatus are two fissures (Santorini), one is at the base of the tragus, the other passes from before backwards. Some ligaments connect the pinna with the head, but others pass from one point of the cartilage to another. The external lignments are condensed bands of fibrous tissue, and are two in number, anterior and posterior. The anterior fixes the fore part of the helix to the root of the zygoma. The posterior passes from the back of the concha to the mastoid process. The chief special ligament crosses the interval between the tragus and the beginning of the helix, and completes the tube of the meatus. The FACIAL NERVE (portio dura, fig. 9), or the seventh cranial nerve, confers contractility on the muscles of the face. Numerous communica- tions take place between it and the fifth nerve ; the chief of these are found above and below the orbit, and over the body of the lower jaw. Dissection. The facial nerve is to be displayed on the right side of the face if there is time sufiicient before the body is turned, otherwise it is to be omitted for the present (see p. 17). Some of the nerve is concealed by the ])arotid gland, but the greater part is anterior to the glandular mass. To expose the ramification of the nerve beyond the parotid gland, let the skin be raised from the face in the same manner as on the left side. The different branches are then to be sought as they escape from beneath the anterior border of the gland, and are to be followed forwards to their termination. The highest branches to the temple have been already partly dissected above the zygomatic arch ; and their junctions with the temporal branch 48 DISSECTION OF THE FACE. of the superior maxillary and with the supra-orbital nerve have been seen. Other still smaller branches are to be traced to the outer part of the orbit, where they enter the eyelids and communicate with tlie other nerves in the lids ; as these cross the malar bone, a junction is to be found with the subcutaneous malar nerve of the fifth. AVith the duct of the parotid are two or more large branches, which are to be followed below the orbit to their junction with the infra-orbital, nasal, and infra-trochlear nerves. The remaining branches to the lower part of the face are smaller in size. One joins with the buccal nerve at the lower part of the buccinator muscle ; and one or two others are to be traced forwards to the lower lip, and to the labial branch of the inferior dental nerve. To follow backwards the trunk of the nerve through the gland, the in- teguments should be taken from the surface of the parotid as on the other side, and the gland should be removed piece by piece. In this proceeding the small branches of communication of the great auricular nerve with oiFsets of the facial, and the deep branches frora the facial to the auriculo- temporal nerve, are to be sought. Lastly, tlie first small branches of the facial to the ear and the digastric and stylo-hyoid muscles, are to be looked for close to the base of the skull before the nerve enters the parotid. The Nerve outside the Skull (fig. 9, ^'). The nerve issues from the stylo-mastoid foramen, after traversing the aqueduct of Fallopius, and furnishes immediately the three following small branches : — The posterior auricular branch (fig. 9, *) turns upwards in front of the mastoid process, where it communicates with an offset of the great auricu- lar, and is said to be joined by a branch to tiie ear from the pneumogastric (cranial) nerve ; it ends in auricular and mastoid offsets (p. 23). The branch to the digastric muscle generally arises in common with the next. It is distributed by many offsets to the posterior belly of the mus- cle near the skull. The branch to the stylo-hyoideus is a long slender nerve, which is directed inwards and enters its muscle about the middle. This branch communicates with the sympathetic nerve on the external carotid artery. As soon as the facial nerve has given off those branches, it is directed forwards through the gland, and divides near the ramus of the jaw into two large trunks — temporo-facial and cervico-facial. The temporo-facial trunk furnishes offsets to the side of the head and face, whose ramifications extend as low as the meatus auditorius. As this trunk crosses over the external carotid artery, it sends downwards branches to join the auriculo-temporal portion of the inferior maxillary nerve ; and in front of the ear it gives some filaments to the tragus of the pinna. Three sets of terminal branches, temporal, malar, and infra-orbi- tal, are derived from the temporo-facial part. The temporal branches ascend obliquely over the zygomatic arch to enter the orbicular muscle, the corrugator supercilii, and the anterior belly of the occipito-frontalis ; they are united with offsets of the supra-orbital nerve (®). The attrahens aurem muscle receives a branch from this set ; and a junction takes ))lace above the zygoma with the temporal branch of the superior maxillary nerve ('"). The malar branches are directed to the outer angle of the orbit, and are distributed to the orbicularis muscle. In the eyelids communications take place with the palpebral filaments of the fifth nerve ; and near the FACIAL NERVE 49 outer part of the orbit, with the small subcutaneous malar branch of the superior maxillary nerve (®). The infra-orhital branches are longer than the rest, and are furnished to the muscles and the integument between the eye and mouth. Close to tlie orbit, and beneath the elevator of the upper lip, a remarkable commu- nication— infra-orbital plexus, is formed between these nerves and the Fig. 9. Na^a) nerve. Tufra-trochlear. Subcutaneous malar. Infra-orbital. 12. Buccal. Cutaneous Branches of the Fifth Nerve in the Face. 13. Labial of inferior dental. 15. Facial or seventh cranial, sending back the posterior auricular branch, 4, and forwards its numerous ofisets to join the branches of the fifth nerve above enumerated. infra-orbital branches of the superior maxillary (^^). After crossing the branches of the fifth nerve, some small offsets of tlie facial nerve pass in- wards to the side of the nose, and others upwards to the inner angle of tlie orbit, to supply the muscles, and to join tlie nasal (^) and infra-trochlear C*) branches of the ophthalmic nerve. 4 50 DISSECTION OF THE ORBIT. The CERVico-FACiAL IS Smaller than the other trunk, and distributes nerves to the lower part of the face and the upper part of the neck. Its highest branches join the lowest offsets of the temporo-facial nerve, and thus complete the network on the face. This trunk, whilst in the parotid, jrives twigs to the gland, and is united with the gi*eat auricular nerve. The terminal branches distributed from it are, buccal, supra-maxillary, and infra-maxillary. The buccal branches pass forwards towards the angle of the mouth, giving offsets to the buccinator muscle, and terminate in the orbicularis oris. On the buccinator they join the branch Q'^) of the inferior maxillary nerve to that muscle. The supra-maxillary branches course inwards above the base of the lower jaw to the middle line of the chin, and supply the muscles and tlie integument between the chin and mouth. Beneath the depressor anguli oris the branches of the facial join offsets of the labial branch of the in- ferior dental nerve Q^) in their course to the middle line. The infra-maxillary branches lie below the jaw, and are distributed to the upper part of the neck. The anatomy of these nerves will be given with the dissection of the anterior triangle of the neck. Section IV. DISSECTION OF THE ORBIT. Directions. The orbit should be learnt on that side on which the mus- cles of the face have been seen. Position. In the examination of the cavity* the head is to be placed in the same position as for the dissection of the sinuses of the base of the skull. Dissection. For the display of the contents of the orbit, it will be neces- sary to take away the cotton w^ool from beneath the eyelids. To remove the bones forming the roof of the space, two cuts may be made with a saw through the margin of the orbit, one being placed at the outer, the other near the inner angle of the cavity ; and these should be continued back- ward with a chisel, along the roof of the orbit, so as to meet near the optic foramen. The piece of bone included in the incisions is now to be tilted forwards, but is not to be taken away. Afterwards the rest of the roof of the orbit, which is formed by the small wing of the sphenoid bone, is to be cut away w^ith the bone forceps, except a narrow ring around the optic foramen ; and any overhanging bone on the outer side, which may interfere with the dissection, may be likewise removed. During the examination of the cavity the eye is to be pulled gently forwards. The periosteum of the orbit, which has been detached from the bone in the dissection, surrounds the contents of the orbital cavity, and joins the dura mater of the brain through the sphenoidal fissure. It encases the contents of the orbit like a sac, and adheres but loosely to the bones. Apertures exist posteriorly in the membrane for the entrance of the dif- ferent nerves and vessels ; and laterally prolongations of the periosteum accompany the vessels and nerves leaving the cavity. OPHTHALMIC NERVE. 51 Dissection. The periosteum is next to be divided along the middle of the orbit, and to be taken away. After the removal of a little fat, the following nerves, vessels, and museles come into view ; but it is not need- ful to remove much of the fat in this stage of the dissection. The frontal nerve and the supra-orbital vessels lie in the centre ; the lachrymal nerve and vessels close to the outer wall ; and the small fourth nerve at the back of the orbit : all these nerves enter the cavity above the muscles. The superior oblique muscle is recognized by the fourth nerve entering it : the levator palpebrie and superior rectus lie beneath the frontal nerve ; and the external rectus is partly seen below the lachrymal nerve. In the outer part of the orbit, near the front, is the lachrymal gland. The frontal and lachrymal nerves should be followed forwards to their exit from the orbit, and backwards with the fourth nerve, through the sphenoidal fissure, to the wall of the cavernous sinus. In tracing them back, it will be expedient to remove the projecting clinoid process, should this still remain ; and some care will be required to follow the lachrymal nerve to its commencement. Contents of the orbit. The eyeball and the lachrymal gland, and a great quantity of granular fat, are lodged in the orbit. Connected with the eye are six muscles — four straight and two oblique ; and there is also an ele- vator of the upper eyelid in the cavity. The nerves in this small space are numerous, viz., the second, third, fourth, ophthalmic of the fifth, and the sixth nerve, together with the small temporo-malar branch of the superior maxillary nerve, and offsets of the sympathetic ; their general distribution is as follows : — The second nerve penetrates the eyeball ; the third is furnished to all the muscles of the cavity but two ; the fourth enters the superior oblique (one of the two ex- cepted) ; and the sixth is spent in the external rectus muscle. The fifth nerve supplies some filaments to the eyeball with the sympathetic, but the greater number of its branches pass through the orbital cavity to the face. The ophthalmic vessels are also contained in the orbit. The lachrymal gland (fig. 10, f) secretes the tears, and is situate in the hollow on the inner side of the external angular process of the frontal bone. It is of a lengthened form, something like an almond, and lies across the eye. From its anterior part a thin accessory piece projects be- neath the upper eyelid. The upper surface is convex, and in contact with the periosteum, to which it is connected by fibrous bands that constitute a ligament for the gland ; the lower surface rests on the eyeball and the external rectus muscle. In structure the lachrymal resembles the salivary glands ; and its very fine ducts, from eight to twelve in number, open by as many apertures in a semicircular line on the inner aspect of the upper eyelid towards the outer canthus. The FOURTH NERVE (fig. 10, ^) is the most internal of the three nerves entering the orbit above the muscles. After reaching this space, it is directed inwards to the superior oblique muscle, which it pierces at the orbital surftice, contrary to the general mode of distribution of the nerves on the ocular surface of tlie muscles. The oriiTiiALMic trunk of the fifth nerve (fig. 10, p. 52), as it ap- proaches the sphenoidal fissure, furnishes from its inner side tlie nasal branch, and then divides into the frontal and lachrymal branches ; the 62 DISSECTION OF THE ORBIT. former passes into the orbit between the heads of the external rectus, but the other two lie, as before said, above the muscles. The frontal 7ierve (fig. 10, ^) is close to the outer side of the fourth as it enters the orbit, and is much larger than the lachrymal branch. In its course to the foreliead the nerve lies along the middle of the orbit, and supplying anteriorly a supra-trochlear brancli (*), leaves that cavity by the supra-orbital notch. Taking the name supra-orbital, it ascends on the forehead, and supplies the external part of the head (p. 21). Fig. 10. Muscles : a. Superior oblique. &. Levator palpebrse. c. External rectus. d. Superior rectus. /. Lachrymal glaud. Nerves : 1. Fourth. 2. Frontal. 3. Lachrymal. 4. Snpra-trochlear. 6. Offset of lachrymal to join tera- poro-malar. First View of the Okbit (Illustrations of Dissections). Whilst in the notch tlie nerve gives palpebral filaments to the upper lid. The supra-trochlear branch {*) passes inwards above the pulley of the upper oblique muscle, and leaves the orbit to end in the eyelid and fore- head (p. 23). Before the nerve turns round the margin of the frontal bone, it sends downwards a branch of communication to the infra-trochlear branch of the nasal nerve. Frequently there are two supra-trochlear branches ; in such instances one arises near the back of tlie orbit. The lachrymal nerve (fig. 10, ^) after entering the orbit in a separate tube of the dura mater, is directed forwards in tlie outer part of the cavity, and beneath the lachrymal gland to the upper eyelid, where it pierces the palpebral ligament, and is distributed to the structure of the lid. The nerve furnishes branches to the lachrymal gland ; and near the gland it sends downwards one or two small filaments (^) to communicate with the temporo-malar or orbital branch of tlie superior maxillary nerve. SUPERIOR OBLIQUE MUSCLE. 63 Occasionally it has a communicating filament behind with the fourth nerve. The nasal nerve is not visible at this stage of the dissection : it will be noticed afterwards at p. 43. Dissection. Divide the frontal nerve about its middle, and throw the ends forwards and backwards : by raising the posterior part of the nerve, the separate origin of the nasal branch from the ophthalmic trunk will appear. The lachrymal nerve may remain uncut. The LEVATOR PALPEBR^ supERiORis (fig. 10, b) is the most superfi- cial muscle, and is attached posteriorly to the roof of the orbit in front of the optic foramen. The muscle widens in front, and bends downwards in the eyelid to be inserted by a wide tendon into the fore part of the tarsal cartilage. By one surface the muscle is in contact with the frontal nerve and the periosteum ; and by the other, with the superior rectus muscle. If it is cut across about the centre a small branch of the third nerve will be seen entering the posterior half at the under surface. Action. The lid-cartilage is made to glide upwards over the ball by this muscle, so that the upper edge is directed back and the lower forwards, the teguments of the lid being bent inwards at the same time. If the eye- ball is directed down, the movement of the lid is less free, because the conjunctiva is put on the stretch. The RECTUS SUPERIOR (fig. 10, ^) is the upper of four muscles that lie arouud the globe of the eye. It arises from the upper part of the optic foramen, and is connected with the other recti muscles around the optic nerve. In front the fleshy fibres end in a tendon, which is inserted, like the other recti, into the sclerotic coat of the eyeball about a quarter of an inch behind the transparent cornea. The under surface of the muscle is in contact with the globe of the eye, and with some vessels and nerves to be afterwards seen ; the other surface is covered by the preceding muscle. The action of the muscle will be given with the other recti (p. 57). The SUPERIOR OBLIQUE MUSCLE (fig. 10, ^) is thin and narrow, and passes through a fibrous loop at the inner angle of the orbit before reach- ing the eyeball. The muscle arises behind from the inner part of the optic foramen, and ends anteriorly in a rounded tendon, which, after pass- ing through the loop before referred to (fig. 11) is reflected backwards and outwards between the superior rectus and the globe of the eye, and is in- serted into the sclerotic coat behind the middle of the ball. The fourth nerve is supplied to the orbital surface of the muscle, and the nasal nerve lies below it. The thin insertion of the muscle lies between the superior and the external rectus, and near the tendon of the inferior oblique. The pulley, or trochlea (fig. 11), is a fibro-cartilaginous ring nearly a quarter of an inch wide, which is attached by fibrous tissue to the depres- sion of the frontal bone at the inner angle of the orbit. A fibrous layer is prolonged from the margins of the pulley on the tendon ; and a synovial membrane lines the ring, to facilitate the movement of the tendon through it. To see the synovial membrane and the motion of the tendon, this pro- longation must be cut away. For the use of the muscle, see the description of the inferior oblique, p. 59. 54 DIHSECTION OF THE ORBIT. Dissection. The superior rectus muscle is next to be divided about the middle, and turned backwards (fig. 11), when a brancli of the third nerve to its under surface will be found. At the same time the nasal nerve and the ophthalmic artery and vein will come into view as they cross inwards above the optic nerve : these should be traced forwards to the inner angle, and backwards to the posterior part of the orbit. By taking away the fat between the optic nerve and the external rectus, at the back of the orbit, the student will find easily fine nerve-threads (ciliary) with small arteries lying along the side of the optic nerve ; and by tracing the ciliary nerves backwards, they will guide to the small len- ticular ganglion (the size of a pin's head) and its branches. The dissector should find then two branches from the nasal and third nerves to the ganglion : the nasal branch is slender, and enters the ganglion behind, and that of the third nerve, short and thick, joins the lower part. Lastly, the student should separate from one another the nasal, third, and sixth nerves, as they pass between the heads of the external rectus muscle into the orbit. The THIRD NERVE is placed highest in the wall of the cavernous sinus (fig. 4, ^) ; but at the sphenoidal fissure it descends b^low the fourth, and the two superficial branches (frontal and laclirymal) of the ophthalmic nerve. It comes into the orbit between the heads of the outer rectus, having previously divided into two parts. The tipper piece (fig. 11, ^), the smallest in size, ends in the under sur- face of the levator palpebral and superior rectus muscles. The lower piece supplies some of the other muscles, and will be dissected afterwards (p. 57). The nasal branch of the ophthalmic nerve (fig. 11/) enters the orbit between the heads of the rectus, lying between *the two parts of the third nerve. In the orbit the nerve is directed obliquely inwards to reach the anterior of the two foramina in the inner wall. Passing through this aperture with the anterior ethmoidal (nasal) artery, the nerve appears in the cranium at the outer margin of the cribriform plate of the ethmoid bone. Finally, it enters the nasal cavity by an aperture at the front of the cribriform plate : and after passing behind the nasal bone, it is directed outwards between that bone and the cartilage, to end on the outer side of the nose. In the orhit the nasal crosses over the optic nerve, but beneath the superior rectus and levator jjalpebrag muscles, and lies afterwards below the superior oblique ; in this part of its course it furnishes tlie following branches : — The branch to the lenticular ganglion (^) is about half an inch long and very slender, and arises as soon as the nerve comes into the orbit : this is the long root of the lenticular ganglion. Long ciliary branches. As the nasal crosses the optic nerve, it supplies two or more ciliary branches (fig. 11) to the eyeball. These lie on the inner side of the optic, and join the ciliary branches of the lenticular ganglion. The infra-trochlear branch Q) arises as the nasal nerve is about to leave the cavity, and is directed forwards below the pulley of the superior oblique muscle, to end in the upper eyelid, the conjunctiva, and the side of the nose. Before this branch leaves the orbit it receives an offset of commu- nication from the supra-troclilear nerve. In the nose (fig. 34). Whilst in the nasal cavity the nerve furnishes OPHTHALMIC ARTERY 55 branches to the lining membrane of the septum narium and outer wall ; these will be subsequently referred to with the nose. Fig. 11. Second View of the Orbit (Illustrations of Dissections). Nerve ft : Muscles : a. Superior oblique. b. Levator palpebne and upper rectus thrown back together. c. External rectus. d. Fore part of upper rectus. /. Lachrymal gland. 1. Nasal nerve beginning outside of the orbit. 2 Its infra-trochlear branch. .3. Lenticular ganglion : — 4. Its branch to the third nerve ; 5. Its branch to the nasal nerve (too large). 6. Branch of third to inferior oblique muscle. 7. Ciliary branches of the nasal nerve. 8. Upper branch of the third. 9. Sixth nerve. 10. Third nerve, outside the orbit. Termination of the nasal nerve (fig. 9). After the nerve becomes cutaneous on the side of the nose, as seen in the dissection of the facial nerve (p. 47), it descends beneath the compressor naris muscle, and ends in the integuments of the wing and tip of the nose. The OPHTHALMIC or LENTICULAR GANGLION of the Sympathetic nerve (fig. 11, ^) is a small round body, of the size of a pin's head, and of a slight red color. It is placed at the back of the orbit between the optic nerve and the external rectus, and commonly on the outer side of, and close to the ophthalmic artery. By its posterior part the ganglion has branches of communication with other nerves (its roots) ; and from the anterior part proceed the ciliary nerves to the eyeball. The ganglion communicates with sensory, motory, and sympathetic nerves. Tlie off'sets of communication are tliree in number. One, the long root (^), is the branch of the nasal nerve before noticed, which joins the bi) DISSECTION OF THE ORBIT. superior angle. A second branch of considerable thickness (short root *) passes from the inferior angle to join the branch of the third nerve that supplies the inferior oblique muscle. And the third root is derived from the sympathetic (the cavernous plexus), either in union with the long root, or as a distinct branch to the posterior border of the ganglion. Branches. The short ciliary nerves (fig. 11) are ten or twelve in number, and are collected into two bundles, which leave the upper and lower angles of the front of the ganglion. In the upper bundle are four or five, and in the lower, six or seven nerves. As they extend along the optic nerve to the eyeball they occupy the outer and under parts, and com- municate with the long ciliary branches of the nasal nerve. The OPHTHALMIC ARTERY, a branch of the internal carotid, is trans- mitted into the orbit through the optic foramen. At first the vessel is outside the optic nerve, but it then courses inwards, over or under the nerve, to the inner angle of the orbit, where it ends in a nasal brancli (external) on the side of the nose (fig. 17, **), and anastomoses with tlie angular and nasal branches of the facial. The branches of the artery are numerous, though inconsiderable in size, and may be arranged in three sets : — one arising outside the optic nerve, another above it, and a third set on the inner side. The lachrymal artery accompanies the nerve of the same name to the upper eyelid, where it ends by supplying that part, and anastomosing witli the palpebral arches. It supplies branches, like the nerve, to the lachry- mal gland and the conjunctiva ; and it anastomoses with the middle men- ingeal by an offset through the sphenoidal fissures. At the front of the orbit it sends a small branch with each of the ter- minal pieces of the temporo-malar nerve ; and these join the temporal anrocess of the superior maxillary bone, pjxternally it is crossed by the ligament of the eyelids, and is covered by an expansion derived from that band, which is fixed to the margin of the bony groove. If the aponeurotic covering be removed, the mucous membrane lining the interior will be seen. Into the outer side of the sac the lachrymal canals open. The duct, ® (ductus ad nasum), is the narrowed part of the tube, and is about half an inch long. It is entirely encased by bone, and corresponds with the passage of the same name in the dried skull. In the nasal cavity it .opens into the front of the inferior meatus, where its opening is guarded by a piece of the mucous membrane. A bent probe introduced through the nostril may be passed into the duct from the meatus, but with destruc- tion of the valve. As the duct is continuous with the mucous membrane of the nose it has the same structure, viz., a fibrous external layer with a mucous lining. The epithelium of the sac and duct is ciliated as in the nose, but in the lachry- mal canals it is scaly. Directions. The examination of the eyeball may be omitted with more advantage to the student till the dissection of the liead and neck has been completed. The description of the eye will be found at the end of the book. Section V. DISSECTION OF THE NECK. Position. For the dissection of the right side of the neck let the head be supported at a moderate height on a block, and let the face be turned to the left side and fastened in that position with hooks. To obtain a good view of the region, the right arm may be drawn under the body, with the object of depressing the point of the shoulder, and putting the neck parts on the stretch. In some bodies, owing to a difference in the form of the neck, the best position will be obtained by placing the upper limb over the chest. Surface-marking. The side of the neck presents a somewhat square out- line, and is limited in the following way: — Below is the prominence of the clavicle ; and above is the base of the lower jaw with the skull. In front the boundary is a line from the chin to the sternum ; and behind, another line from the occiput to tlie acromial end of the clavicle. The part thus included is divided into two triangular spaces (anterior and pos- terior) by the diagonal line of the projecting sterno-mastoid muscle. And in consequence of the position of that muscle the base of the anterior space is at the jaw, and the apex at tlie sternum ; whilst the base of the posterior one is at the clavicle, and the apex at the head. The surface in front of the sterno-mastoid is depressed at the upper part 62 DISSECTION OF THE NECK. of the neck, near the position of the carotid vessels ; and behind the muscle, just above the clavicle, is another slight hollow which points to the situa- tion of the subclavian artery. Along the middle line of the neck the following parts can be recognized through the skin : — About two inches and a half from the base of the jaw is the eminence of the os hyoides, with its cornu extending laterally on each side. Below this may be felt the wide prominence of the thyroid cartilage, called pomum Adami, which is most marked in man : and be- tween the cartilage and the hyoid bone is a slight interval, corresponding with the thyro-hyoid membrane. Inferior to the thyroid, is the narrow^ prominent ring of the cricoid car- tilage ; and between the two the linger may distinguish another interval, which is opposite the crico-thyroid membrane. In some bodies, especially in women, the swelling of the thyroid gland may be felt by the side of the trachea. From the cricoid cartilage to the sternum, and between the sterno-mas- toid muscles, is a depression, whose depth is much increased in emaciated persons, in which the tube of the trachea can be recognized. Direction. As the time for turning the body will not allow tlie examina- tion of the whole side of the neck, the student should lay bare in this stage only the parts behind the sterno-mastoid muscle. Dissection. To raise the skin from the posterior triangle of the neck, make an incision along the sterno-mastoid muscle from the one end to the other, and afterwards along the clavicle as far as the acromion. The tri- angular flap of skin is to be reflected from before back towards the trapezius muscle. The superficial fascia which will then be brought into view, con- tains the platysma ; and to see that muscle, it will be necessary to take the subcutaneous fat from the surface of the fibres. The PLATiSMA MYOiDES is a thin subcutaneous muscular layer, which is now seen only in its lower half. The muscle is placed across the side of the neck, and extends from the top of the shoulder to the face. Its fleshy fibres take origin by fibrous bands from the clavicle and the acro- mion, and below those bones from the superficial fatty layer covering the pectoral and deltoid muscles ; ascending through the neck, the fibres are inserted into the jaw. The lower part of the muscle is more closely united to the skin than the upper, and covers the external jugular vein as well as the lower part of the posterior triangle. At first the fibres of the muscle are thin and scat- tered, but they increase in strength as they ascend. The oblique direc- tion of the fibres should be noted, because in venesection in the external jugular vein the incision is to be so made as to divide them across. The use will be found with the description of the remainder of the muscle. Dissection. The platysma is now to be cut across near the clavicle, and to be reflected upwards as far as the incision over the sterno-mastoid muscle, but it is to be left attached at that spot. In raising the muscle the student must be careful of tlie deep fascia of the neck ; and he should dissect out the external jugular vein, and the superficial descending branches of the cervical plexus, which are close beneath the platysma. The external jucfidar vein (fig. 14, ^) commences in the parotid gland (p. 42), and is directed backwards beneath the platysma to the lower part of the neck, where it pierces the deep cervical fascia to open into the sub- clavian vein. Its course down the neck will be marked by a line from POSTERIOR TRIANGULAR SPACE. 63 the angle of the jaw to the middle of the clavicle. Beyond the sterno- mastoid muscle the vien is dilated, and the swollen part {sinus) is limited by two pairs of valves — one being situate below at the mouth of the vein, and the other near the muscle. Small superficial branches join the vein, and an offset connects it with the anterior jugular vein. Its size, and the height at which it crosses the sterno-mastoid muscle, are very uncertain. The deep cervical fascia consists, like the aponeuroses in other regions of the body, of a superficial layer which surrounds the neck continuously, and of processes that are prolonged inwards between the muscles. In some bodies this fascia is thin and indistinct. In its extent round the neck the membrane incases the sterno-mas- toideus, and presents a different disposition before and behind that muscle. As now seen passing backwards from the muscle, the fascia continues over the posterior triangular space, and incloses the trapezius in its progress to the spines of the vertebrae. At the lower part of the neck it is attached to the clavicle and is perforated by the external jugular vein, and the cutaneous nerves. After the superficial layer has been removed near the clavicle, a deep process may be observed to surround the small omo-hyoid muscle, and to extend under the clavicle, where it is fixed to the back of that bone, and the inner end of the first rib. POSTERIOR TRIANGULAR SPACE. This space (fig. 14), having the form and position before noted, is about eight inches in length. It contains the cervical and brachial plexuses, with the portion of the subclavian artery on which a ligature is usually placed, and some offsets of the vessel and the nerves. Dissection. By the removal of the cervical fascia and the fat between the sterno-mastoid and trapezius muscles, the posterior triangle of the neck will be displayed. In the execution of this task, the student may obtain some assistance by attending to the following remarks : — Crossing the space obliquely about an inch above the clavicle, and dividing it into two, is the small omo-hyoid muscle (fig. 14, '). Close to or under the upper border of the muscle lie the small nerve and vessels to it : the nerve being traceable to the descendens noni, and the artery to the supra-scapular. Above the omo-hyoid muscle will be found the ramifications of the branches of the cervical plexus, together with the spinal accessory nerve ; the latter will be recognized by its piercing sterno-mastoid muscle. The greater number of the branches of the cervical plexus descend in the space to the shoulder ; but the small occipital and great auricular nerves ascend to the head, and the superficial cervical branch is directed forwards over the sterno-mastoid muscle. Below the omo-hyoideus are the subclavian artery and the brachial plexus, which have a deep })Osition. In this part also the following ves- sels and nerve are to be sought, viz., the supra-scapular vessels behind the clavicle; the transverse cervical vessels which are higher in the neck, but take an outward direction beneath the omo-hyoid muscle ; and, lastly, the small branch of nerve to the subclavius muscle, which lies about the mid- dle of the space between the clavicle and omo-hyoideus. Underneath the trapezius, where it is attached to the clavicle, the 64 DISSECTION OF THE NECK. v^eiTatus magnus muscle appears ; and behind the large cervical nerves, towards the lower part of the space, is placed the middle scalenus muscle. Ulirough the scalenus issue two muscular nerves ; one, formed by two roots, for the serratus magnus ; the otiier smaller, and higher up, for the rhomboidei. Fig. 14. Part of the Posterior Triangle op the Neck is here displayed, but the student should carry the dissection as high as the head, so as to lay bare the whole of that space. 1. Steruo-mastoideus. 1 Trapezius. 3. Posterior belly of the omo-hyoid miiscle. 4. Anterior scalenus, with the phrenic nerve oil it. ;'). Middle scalenus muscle. Elevator of the angle of the scapula. Third part of the subclavian artery. External jugular vein joining the subcl: vian below. Nerves of the brachial plexus. Spinal accessory nerve. (Blandin's Surgical Anatomy.) Limits of the space. The space is bounded in the front by the sterno- mastoid muscle, ^ ; and behind by the trapezius, '•'. Its base corresponds with the middle third of the clavicle, and its apex is at the skull. In its POSTERIOR TRIANGULAR SPACE. 65 area are several muscles, which are placed in the following order from above down, viz., splenius capitis, levator anguli scapulae * ; and the mid- dle scalenus * ; and at the lower and outer angle, somewhat beneath the trapezius lies the upper part of the serratus magnus. Covering the space are the structures already examined, viz., the skin and superficial fascia, the platysma over the lower half or two-thirds, and the deep fascia. The small omo-hyoid muscle, ', crosses the lower part of the space, so as to subdivide it into two — a lower or clavicular, and an upper or occi- pital. The clavicular part is small in size and close to the clavicle, and con- tains the subclavian artery. It is triangular in form, with its base directed forwards ; and is bounded in front by the sterno-mastoid, ^ ; above by the omo-liyoid muscle, ' ; and below by the clavicle. This small space meas- ures commonly about one inch and a half from before backwards, and about half that in front at its base. Crossing the area of this portion, rather above the level of the clavicle, is the trunk of the subclavian artery, ^ (its third part), which issues from beneath the anterior scalenus muscle, and is directed over the first rib to the axilla. In the ordinary condition of the vessel the companion subcla- vian vein is seldom seen, owing to its situation being lower down beneath the clavicle. Above the artery are the large cords of tlie brachial plexus, ', which accompany the vessel, and become closely applied to it beneath the clavicle. Behind the artery and the nerves is the middle scalenus muscle, ^. And below the vessel is the first rib. Along the lower boundary of the space, and rather beneath the clavicle lie tlie supra-scapular vessels ; and crossing the upper angle, at the meet- ing of the omo-hyoid and sterno-mastoid muscles, are tlie transverse cer- vical vessels. Entering the space from above is the external jugular vein, ®, which descends over or under the omo-hyoideus near the anterior part, and opens into the subclavian vein ; in this spot the vein receives the supra-scapular and transverse cervical branches, and sometimes a small vein, over the clavicle, from the cephalic vein of the arm. The size of the clavicular part of the space from before back is influ- enced by the attachment of the trapezius and sterno-mastoid muscles along the clavicle : in some bodies these muscles occupy nearly the whole length of that bone, leaving but a small interval between them ; and in others they meet so as to cover the underlying vessels. This space may be fur- ther increased or diminished from above down by the position of the omo- hyoideus in the neck ; for this muscle may lie close to the clavicle, being attached thereto, or it may be distant one inch and a half from that bone. In depth the space varies naturally ; and in a short thick neck with a prominent clavicle, the artery is farther from the surface than in the op- posite condition of the parts. But the depth may be altered much more by the position of the clavicle, according as the limb may be raised or de- pressed. And lastly, the artery may be concealed entirely in its usual position by forcing upwards the arm and shoulder, as the collar bone can be raised above the level of the omo-hyoid muscle. The situation of the trunk of the subclavian artery may vary much, for the vessel may be one inch and a half above the clavicle, or at any point intermediate between this and its usual level just above the prominence of that bone. Further, its position to the anterior scalenus may be changed ; and instead of the vessel being beneath, it may be in front of, or even between the fibres of that muscle. 66 DISSECTION OF THE NECK. Commonly there is not any branch connected with the artery in this part of its course; but the posterior scapular branch (fig. 14) may take origin from it at different distances from the scalenus, or there may be more than one branch (Quain). The subclavian vein rises upwards not unfrequently as high as the artery, or it may even lie with the artery beneath the anterior scalenus in some rare instances. The position of the external jugular vein with regard to the subclavian artery is very uncertain ; and the branches connected with the lower end may form a kind of plexus over the arterial trunk. The occipital part of the posterior triangle is larger than the other. Its boundaries in front and behind are the sterno-mastoid and tlie trapezius ; and it is separated from the clavicular portion by the omo-hyoid muscle. In it are contained chiefly the ramifications of the cervical plexus ; and a chain of lymphatic glands lies along the sterno-mastoid muscle. The spinal accessory nerve, ^®, is directed obliquely across this interval from the sterno-mastoid muscle, which it pierces, to the under surface of the trapezius ; and a communication takes place between this cranial and the spinal nerves in the space. Superficial Branches of the Cervical Plexus. Behind the sterno-mastoid muscle appear some of the ramifications of the cervical nerves in the plexus of the same name ; and superficial branches are fur- nished from these both upwards and downwards. The ASCENDING SET (fig. 14) are three in number, viz., small occipital, great auricular, and superficial cervical. The small occipital branch (fig. 2, ^) comes from the second cervical nerve, and is directed upwards to the head along the posterior border of the sterno-mastoid muscle. At first the nerve is beneath the fascia ; but near the occiput it becomes cutaneous, and is distributed between the ear and the great occipital nerve (p. 24). Occasionally there is a second cuta- neous nerve to the head. The great auricular nerve (fig. 2, ^) is a branch of the part of the plexus formed by the second and third cervical nerves. Perforating the deep fascia at the posterior border of the sterno-mastoid muscle, the nerve is directed upwards beneath the platysma to the lobule of the ear, where it ends in the following branches : — The facial branches are sent forwards to the integuments over the parotid, and a few slender filaments pass through the gland to join the facial nerve. The auricular branches ascend to the external ear, and are chiefly dis- tributed on its cranial aspect ; one or more reach the opposite surface by piercing the pinna. On the ear they communicate with branches furnished from the facial and pneumogastric nerves. The mastoid branch is directed backwards to the integuments between the ear and the mastoid process ; and it joins the posterior auricular branch of the facial nerve (p. 23). The superjicial cervical nerve (fig. 2, '*) springs from the same source as the preceding, and turns forwards round the sterno-mastoid muscle about the middle. Afterwards it pierces the fascia and platysma, and ramifies over the anterior triangular space (see p. 68). There may be more than one branch to represent this nerve. The DESCENDING SET of branches (fig. 2) (supra-clavicular), are de- rived from the third and fourth nerves of the plexus, and are directed FORE PART OF NECK. 67 towards the clavicle over the lower part of the triangular space. Their number is somewhat uncertain, but usually there are about tliree on the clavicle. The most internal branch (sternal) crOvSses the clavicle near its inner end ; the middle branch lies about the middle of that bone ; and the posterior (acromial) turns over the attachment of the trapezius to the acromion. All are distributed in the integuments of the chest and shoulder. Derived from the descending set are two or more posterior cutaneous cervical nerves, wiiich ramify in the integument over tl»e lower two thirds of the fore part of the trapezius. The lymphatic glands (glandulae concatenatae) lie along the sterno- mastoid muscle, and are continuous at the low^er part of the neck with the glands in the cavity of the thorax. There is also a superficial chain along the external jugular vein. Dissection. The dissection of the posterior triangle should be repeated on the left side of the neck, in order that the difference in the vessels may be observed. Afterwards the reflected parts are to be replaced and care- fully fastened in their natural position with a few stitches, preservative fluid or salt having been previously applied. Directions. It is supposed that the body will now be turned on the fore part for the examination of the Back ; and during the time allotted for this position the dissector of the head is to learn the posterior part of the neck. (Dissection of the Back.) After the completion of the Back, the student should take out the spinal cord, and then return to the dissection of the front of the neck, which is described below. FRONT OF THE NECK. Directions. Supposing the thorax and Back finished, the head and neck may be detached from the trunk by dividing the spinal column be- tween the second and third dorsal vertebrte, and cutting through the arch of the aorta beyond its large branches (if this is not done), so as to take that piece of tlie vessel with the head. The dissector continues his work on the remainder of the right side of the neck ; but if the facial nerve has been omitted, it should be first learnt (p. 47). Position. Supposing the facial nerve completed, a small narrow block is to be placed beneath the left side of the neck, and the face is to be turned from the dissector. Further, the neck is to be made tense by means of hooks, the chin being well raised at the same time. Dissection. An incision along the base of the jaw on the right side (if it has not been made already) will readily allow the piece of integument in front of the sterno-mastoideus to be raised towards the middle line. Beneath the skin is the superficial fascia, containing very fine offsets of the superficial cervical nerve. To define the platysma muscle, remove the fat which covers it, carrying the knife down and back in the direction of the fleshy fibres. Platysma Myoides. Tlie anterior part of the platysma, viz., from the sterno-mastoid muscle to the lower jaw, covers the greater portion of the anterior triangular space. At the base of the jaw it is inserted be- tween the symphysis and the masseter muscle ; while other and more posterior fibres are continued over the face, joining the depressor anguli 68 DISSECTION OF THE NECK. oris find risorius, as far as the fascia covering the parotid gland, or even to tlie cheek bone. The fibres have the same appearance in this as in the lower lialf of the muscle, but they are rather stronger. Below the chin the inner fibres of opposite muscles cross for a distance of about an inch, but those which are superficial do not belong always to the same side. Action. The ordinary action of this muscle is confined to the skin of the neck, which it throws into longitudinal wrinkles; but it can depress the corner of the mouth by the slip prolonged to the face. Tlirough its attachment to the jaw it will assist in opening the mouth. Dissection. Raise the platysma to the base of the jaw, and dissect out the branches of the superficial cervical nerve, and the cervical branches of the facial nerve that are beneath it. Clean also the deep fascia of the neck, and the anterior jugular vein which is placed near the middle line. The superficial cervical nerve has been traced from its origin in the cervical plexus to its position on the deep fascia of the neck (p. G6) ; but the nerve may arise from the plexus by two pieces. Beneath the platysma it divides into an ascending and a descending branch : — The ascending branch perforates the platysma, supplying it, and ends in the integuments over the anteriqr triangle, about half way down the neck. Whilst this branch is beneath the platysma it joins the facial nerve. The descending branch likewise passes through the platysma, and is distributed to the teguments below the preceding, reaching as low as the sternum. The infra-maxillary branches of the facial or seventh cranial nerve (rami subcutanei colli) (p. 50) pierce the deep cervical fascia, and pass forwards beneath the platysma, forming arches across the side of the neck (fig. 9), which reach as low as the hyoid bone. Most of the branches end in the platysma, but a few filaments perforate it, and reach the integu- ments. Beneath the muscle there is a communication between the branches of the facial and the offsets of the superficial cervical nerve. Dissection. Cut across the external jugular vein about the middle, and throw the ends up and down. Afterwards the superficial nerves of the neck may be divided in a line with the angle of the jaw, the anterior ends being removed, and the posterior reflected. The great auricular nerve may be cut through and the ends reflected. The part of the deep cervical fascia in front of the sterno-mastoideus is stronger than that behind the muscle, and has the following arrangement. Near the sternum the fascia forms a white firm membrane, which is at- tached to that bone ; but higher in the neck it becomes thinner, and is fixed above the lower jaw and the zygoma, covering also the parotid gland. From the ramus of the jaw a piece is prolonged downwards, be- tween the parotid and submaxillary glands, to join the styloid j)rocess ; this piece is named the stglo-maxillary ligament. And from the angle of the jaw a strong piece is continued to the sterno-mastoideus, which fixes forwards the anterior border of that muscle. Layers of the membrane are prolonged between the muscles ; and that beneath the sterno-mastoid is connected with the sheath of the cervical vessels. One of these beneath the sterno-thyroid muscle, descends in front of the great vessels at the root of the neck to the arch of the aorta, and the pericardium. ANTERIOR TRIANGULAR SPACE. 69 ANTERIOR TRIANGULAR SPACE. This space (fig. 15) contains the carotid vessels and their branches, with many nerves ; and it corresponds with the hollow on the surface of the neck in front of the sterno-mastoid muscle. Dissection. To define the anterior triangular space and its contents, take away the deep fascia of the neck, and the fat, but without injuring or displacing the several parts. First clean the surface of the hyoid mus- cles that appear along the middle line, leaving untouched the anterior jugular vein. The trunks into which the large carotid artery bifurcates are to be fol- lowed upwards, especially the more superficial one (external carotid), whose numerous branches are to be traced as far as they lie in the space. In removing the sheath from the vessels, as tliese appear from beneath the muscles at the lower part of the neck, the dissector should be careful of the small descending branch of the hypo-glossal nerve in front of it. In the slieath between the vessels (carotid artery and jugular vein) will be found the pneumogastric nerve, and behind the sheath is the sympathetic nerve. Crossing the space, in the direction of a line from the mastoid process to the hyoid bone, are the digastric and stylo-hyoid muscles, with several nerves directed transversely. Thus lying below them is the hypo-glossal nerve, which gives one branch (descendens noni) in front of the sheath, and another to the thyroid-hyoid muscle. Above the muscles, and taking a similar direction between the two carotid arteries, are the glosso-pharyn- geal nerve and the stylo-pharyngeus muscle. Directed downwards and backwards from beneath the same muscles to the sterno-mastoideus, is the spinal accessory nerve. On the inner side of the vessels, between the hyoid bone and the thy- roid cartilage, the dissector will find the superior laryngeal nerve ; and by the side of the larynx, with tlie descending part of the superior thyroid artery, the small external laryngeal branch. Clean then the submaxillary gland close to the base of the jaw ; and on partly displacing it from the surface of the mylo-hyoid muscle, the student will expose the small branch of nerve to that muscle with the submental artery. The interval between the jaw and the mastoid process is supposed to be already cleaned by the removal of the parotid gland in the dissection of the facial nerve. Limits of the space. Behind, is the sterno-mastoid muscle, ^ ; and in front, a line from the chin to the sternum, along the middle of the neck. Above, at the base of the space, would be the lower jaw, the skull, and the ear ; and below, at the apex, is the sternum. Over this space are placed the skin, the superficial fascia with the platysma, the deep fascia, and the ramifications of the facial and superficial cervical nerves. Muscles in the space. In the area of the triangular interval, as it is above defined, are seen the larynx, and pharynx in part, and many mus- cles converging towards the hyoid bone as a centre, some being above and some below it. Below are the depressors of that bone, viz., omo- hyoid, sterno-hyoid, and sterno-thryoid, ^ to *; and above the os hyoides are the elevator muscles, viz., mylo-hyoid, digastric,,and stylo-hyoid. Con- 70 DISSECTION OF THE NECK. nected with the back of the hyoid bone and the layrnx are some of the constrictor muscles of the gullet. Vessels in the triangular space. The carotid bloodvessels, ^ and '', occupy the hinder and deeper part of the space along the side of the sterno-mastoid muscle ; and their course would be marked on the surface by a line from the sterno-clavicular articulation to a point midway between the jaw and the mastoid process. As high as the level of the cricoid car- tilage they are buried beneath the depressor muscles of the os hyoides ; but beyond that spot they are covered by the superficial layers over the space, and by the sterno-mastoid muscle which, before the parts are dis- placed, conceals the vessels as far as the parotid gland. For a short distance after its exit from beneath the muscles at the root of the neck, the common carotid artery remains a single trunk, ^; but opposite the upper border of the thyroid cartilage it divides into two large vessels, external and internal carotid. From the place of division these trunks are continued onwards, beneath the digastric and stylo-hyoid mus- cles, to the interval between the jaw and the mastoid process. At first the trunks lie side by side, the vessel destined for the internal parts of the head (internal carotid) being the more posterior or external of the two; but above the digastric muscle it becomes deeper than the other. The more superficial artery (external carotid) furnishes many branches to the neck and the outer part of the head, vi?., some forwards to the larynx, tongue, and face; others backwards to the occiput and the ear; and others upwards to the head. But the common carotid does not always divide, as here said. For the point of branching of the vessel may be moved from the upper border of the thyroid cartilage, either upwards or downwards, so that the trunk may remain undivided till it is beyond the os hyoides, or end in branches opposite the cricoid cartilage. The division beyond the usual place is more frequent than the branching short of that spot. It may ascend as an undivided trunk (though very rarely), furnishing offsets to the neck and head. In close contact with the outer side of both the common and the internal carotid artery, and incased in a sheath of fascia with them, is the large internal jugular vein, which receives branches in the neck corresponding with some of the branches of the superficial artery. In some bodies the vein may cover the artery, and the branches joining it above may form a kind of plexus over the upper part of the common carotid. Nerves in the space. In connection, more or less intimate, with the large vessels, are the following nerves with a longitudinal direction : — In front of the sheath lies the descending branch of the hypo-glossal nerve ; within the sheath, between the carotid artery and jugular vein, is the pneumogastric nerve; and behind the sheath is the sympathetic nerve. Along the outer part of the vessels the spinal accessory nerve extends for a short distance, till it {)ierces the sterno-mastoid muscle. Several nerves are placed across the vessels : — thus, directed transversely over the two carotids, so as to form an arch below the digastric muscle, is the hypoglossal nerve, which gives downwards its branch (descendens noni) most commonly in front of the sheath. Appearing on the inner side of the carotid arteries, close to the base of the space, is the glosso-pharyngeal nerve, which courses forwards between them. Inside the internal carotid artery, opposite the hyoid bone, the superior laryngeal nerve comes into STERNO-CLEIDO-MASTOJDEUS. 71 sight; whilst a little lower down, with the descending branches of the tliyroid artery, is the external laryngeal branch of that nerve. Glands in the space. Two. glandular bodies, the submaxillary, ", and thyroid, ^^, have their seat in this triangular space of the neck. The sub- maxillary gland is situate altogether in front of the vessels, and is partly concealed by the jaw ; and beneath it on the surface of the mylo-hyoideus is the small nerve to that muscle; with the submental artery. By the side of the thyroid cartilage, between it and the common carotid artery, lies the thyroid body beneath the sterno-thyroid muscle : in the female this body is more largely developed than in the male. At the base of the space, if the parts were not disturbed, w^ould be the parotid gland, which is wedged into the hollow between the jaw and the mastoid process, and projects somewhat below the level of the jaw. Its connections have been noticed at p. 41. Directions. The student has to proceed next with the examination of the individual parts that have been referred to with the triangular spaces. Anterior jugular vein. This small vein occupies the middle line of the neck, and its size is dependent upon the degree of development of the ex- ternal iugrular. Beginning in some small branches below the chin, the vein descends to the sternum, and then bends outwards beneath the sterno- mastoid muscle, to open into the subclavian vein, or into the external jugular. In the neck the anterior and external jugular veins communicate. There are two anterior veins, one for each side, though one is usually larger than the other; and at the bottom of the neck they are joined by a transverse branch. The STERNo-CLEiDO-MASTOiD MUSCLE (fig. 15, ') forms the superficial prominence of the side of the neck. It is narrower in the centre than at the ends, and is attached below by two heads of origin, which are separated by an elongated interval. The inner head is fixed by a narrowed tendon to the anterior surface of the first piece of the sternum ; and the outer head lias a wide fleshy attachment to the sternal third of the clavicle. From this origin the heads are directed upwards, the internal passing backwards, and the external almost vertically, and are blended about the middle of the neck in a roundish belly. Near tlie skull the muscle ends in a tendon, which is inserted into the mastoid process at the outer aspect from base to tip, and by a thin aponeurosis into a rough surface behind that process, and into the outer part of the upper curved line of the occipital bone. The muscle divides the lateral surface of the neck into two triangular spaces. On its cutaneous aspect the sterno-mastoid is covered by the com- mon integuments, by the platysma and deep fascia, and by the external jugular vein and the superficial branches of the cervical plexus (across the middle). If the muscle be cut through below and raised, it w^ill be seen to lie on the following parts : The clavicular origin is superficial to the anterior scalenus and omo-hyoid muscles ; and the sternal head conceals the depressors of the hyoid bone, and the common carotid artery with its vein and nerves. After the union of the heads, the muscle is placed over the cervical plexus, and the middle scalenus and elevator of the angle of the scapula ; and near the skull, on the digastric and splenius muscles, the occii)ital artery, and part of the parotid gland. The spinal accessory per- forates the muscular fibres about the u|)per third. Action. Both muscles acting bend tlie head forwards ; but one muscle turns the face to the opposite side. In conjunction w'ith the muscles at- 72 DISSECTION OF THE NECK. taclied to the mastoid process one steriio-rnastoideus will incline the head towards the shoulder of the same side. Fig. 15. View of the Anterior Triangular Space of the Neck (Quain's "Arteries"). 1. Sterno-rnastoideus. 7 Internal juy:ular veia. 2. Sterno-hyoideus. 8. External jugular vein.— In the Drawing 3. Anterior belly of the omo-hyoideus. from which this cut is copied the steruo-raas- i. Thyro-hyoideus. toid is partly cut through. 6. Common carotid artery dividing. In laborious respiration the two muscles will assist in elevating the ster- num. The OMO-iiYOiD MUSCLE crosses beneath the sterno-mastoideus, and consists of two fleshy bellies united by a small round intermediate tendon (fig. 14, '). The origin of the muscle from the scapula, and the connec- tions of the posterior part, are to be studied in the dissection of the Back. From the intervening tendon the anterior fleshy belly (fig. 15, *) is directed upwards along the outer border of the sterno-liyoid nuiscle, and is inserted into the lower part of the body of the hyoid bone, close to the great cornu. The anterior belly is in contfict with the fascia, after escaping from be- neath the sterno-mastoid ; and rests on the sterno-thyroideus. This part of the muscle crosses the common carotid artery and internal jugular vein on a level with the cricoid cartilage. Action. The anterior belly depresses the hyoid bone ; and the posterior DEPRESSORS OF OS HYOIDES. 73 is said by Theile to make tense tlie deep fascia of the neck with which it is connected. The STERNO-iiYOiD MUSCLE (fig. 15, ^) is a flat thin band nearer the middle line than the preceding. It arises from the posterior surface of the sternum and the cartilage of the first rib. From this spot the fibres ascend, and are inserted into the lower border of the body of the os hyoides, inter- nal to the preceding muscle. One surface is in contact with the fascia, and is often marked by a ten- dinous intersection near the clavicle. When the muscle is divided and turned aside, the deep surface will be found to touch the sterno-thyroideus, and the superior thyroid vessels. The muscles of opposite sides are sepa- rated by an interval which is largest below. Action. It draws the os hyoides downwards after swallowing ; and in laborious respiration it will act as an elevator of the sternum. The STERNO-TiiYROiD MUSCLE is wider and shorter than the sterno- hyoid, beneath which it lies. Like the other hyoid muscle, it arises from the posterior surface of the sternum, and the cartilage of the first rib below the former ; and it is inserted into the oblique line on the side of the thy- roid cartilage, where it is continuous with the thyro-hyoid muscle. The inner border touches its fellow for about an inch, along the middle line of the neck, whilst the outer reaches over the carotid artery. The superficial surface is concealed by the preceding hyoid muscles ; and the opposite surface is in contact with the lower part of the common carotid artery, the trachea, and the larynx and thyroid body. A transverse, ten- dinous line crosses the muscle near the sternum. Action. Its chief use is to aid the preceding muscle in lowering rapidly the hyoid bone after deglutition ; but it can draw down and forwards the thyroid cartilage, and assist in rendering tight the vocal cords. Like the sterno-hyoid it participates in the movement of the chest in laborious breathing. The THYRO-HYOiDEus (fig. 15, *) is a continuation in direction of the last muscle. Beginning on the side of the thyroid cartilage, the fibres ascend to the inner half of the great cornu of the os hyoides, and to the outer part of the body of the bone. On the muscle lies the omo-hyoideus ; and beneath it are the superior laryngeal nerve and vessels. It is sometimes considered one of the special muscles of the larynx. Action. Raising the thyroid cartilage towards the os hyoides, it renders lax the vocal cords, and assists in placing the cartilage under the tongue preparatory to swallowing. Directions. — The remaining parts included in this section are the scaleni muscles and the subclavian bloodvessels, with the cervical nerves and the carotid bloodvessels. The student may examine them in the order here given. Dissection (fig. IG). Supposing the sterno-mastoid cut, the fiit and fascia are to be taken away from tlie lower part of the neck, so as to pre- pare the scaleni muscles with the subclavian vessels and their branches. By means of a little dissection the anterior scalenus muscle will be seen ascending from the first rib to the neck, having the phrenic nerve and sub- clavian vein in front of it, the latter crossing it near the rib. The part of the subclavian artery on the inner side of the scalenus is then to be cleaned, care being taken not only of its branches, but of the branches of the sympathetic nerve which course over and along it from the 74 DISSECTION OF THE NECK. neck to the chest. Tliis dissection will be facilitated by the removal of a part or the whole of the clavicle. All the branches of the artery are in general easily found, except the superior intercostal, which is to be sought in the tliorax in front of the neck of the first rib. On the branch (inferior thyroid) ascending to the Fig. 16. A VIEW OF THB Common Carotid akd Subclavian Arteries (Quain's " Arteries"). 1. Anterior scalenus, with the phrenic nerve on it. 2. Middle scalenus. .3. Levator anguli scapulse. 4. Oinohyoideus. 5. Rectus capitis anticus major. 6. Common carotid artery. 7. Subclavian vein. 8. Subclavian artery. 9. Digastric muscle. 10. Parotid gland. 11. Submaxillary gland. 12. Thyroid body. 13. Trapezius muscle, reflected. thyroid body, or near it, is the middle cervical ganglion of the Sympathetic ; and the dissector should follow downwards from it a small cardiac nerve to the thorax. Only the origin and first part of the course of the arterial branches can be now seen ; their termination is met with in other stages of this dissection, or in tlie dissection of other parts of the body. Now the student should seek the small right lympliatic duct that opens into the subclavian vein near its junction with the jugular. A notice of it will be given with the lympliatics of the thorax. SCALENI MUSCLES. 75 The outer part of the subclavian artery having been already prepared, let the dissector remove more completely the fibrous tissue from the nerves of the brachial plexus. From the plexus trace the small branch to the subclavius muscle ; and the branches to the rhomboid and serratus muscles, which pierce the middle scalenus. If it is thought necessary, the anterior scalenus may be cut through after the artery has been studied. Clean the cervical plexus, and seek its muscular branches, the small twigs to join the descendens noni, and the roots of the phrenic nerve. Lastly, let the middle scalenus muscle be defined, as it lies beneath the cervical nerves. The SCALENI muscles are usually described as three in number, and are named from their relative position, anterior, middle, and posterior ; they extend from the first two ribs to the transverse processes of the cervical vertebrae. The SCALENUS ANTicus (fig. 16, ^) extends from the first rib to the lower cervical vertebras, and is somewhat conical in shape. It is attached by its apex to the inner border and the upper surface on the first rib, so as to surround the rough surface or projection on this aspect of the bone ; and by its base it is inserted into the anterior transverse processes of four of the cervical vertebrae, viz., sixth, fifth, fourth, and third (fig. 45, ^). More deeply seated below than above, the muscle is concealed by the clavicle and the subclavius, and by the clavicular part of the sterno-mas- toid : the phrenic nerve lies along its cutaneous surface, and the subclavian vein crosses over it near the rib. Along the inner border is the internal jugular vein. Beneath the scalenus are the pleura, the subclavian artery, and the nerves of the brachial plexus. The insertion into the vertebrae corresponds with the origin of the rectus capitus anticus major muscle. Action. The anterior of these muscles raises strongly the first rib, in consequence of its forward attachment. If the rib. is fixed, it bends for- ward the lower part of the neck. The scALENius MEDius MUSCLE (fig. 16, ^) is larger than the anterior, and extends farthest of all on the vertebrae. Inferiorly it is attached to a groove on the upper surface of the first rib, extending obliquely forwards from the tubercle to the outer border for one inch and a half. The muscle ascends behind the spinal nerves, and is inserted into the tips of the poste- rior transverse processes of all the cervical vertebra (fig. 45, ^). In contact with the anterior surface are the subclavian artery and the spinal nerves, together with the sterno-mastoid muscle ; whilst the poste- rior surface touches the posterior scalenus, and the deep lateral muscles of the back of the neck. The outer border is perforated by the nerves of the rhomboid and serratus muscles. Action. Usually it elevates the first rib. With the rib fixed, the cer- vical part of the spine will be inclined laterally by one muscle. Tiie SCALENUS POSTICUS (fig. 45, ^) is considerable in size, and appears to be but part of the preceding. It is attached below by a slip, about half an inch wide, to the second rib, in front of the serratus posticus superior; and it is inserted above with the scalenus medius into two or three of the lower cervical transverse processes. Action. It acts as an elevator of the second rib ; and its fibres having the same direction as those of the medius, it will incline the neck in the same way. Tiie SUBCLAVIAN ARTERY (fig. 16) is the first part of the large vessel supplying the upper limb with blood, which is thus designated from its 76 DISSECTION OF THE NECK. position beneath the clavicle. This vessel (^) is derived from the branch- ing of the innominate artery behind the sterno-clavicular articulation, and the part of it named subclavian extends as far as the lower border of the first rib. To reach the limb the artery crosses the lower part of the neck, taking an arched course over the bag of the pleura and the first rib, and between the scaleni muscles. For the purpose of describing its numerous connections the vessel may be divided into three parts : the first extending from the sterno-clavicular articulation to the inner border of the interior scalenus ; the second, beneath the scalenus ; and the third, from the outer border of that muscle to the lower edge of the first rib. First part. Internal to the anterior scalenus the artery lies deep in the neck, and ascends slightly from its origin. Between the vessel and the surface will be found the common integumentary coverings with the pla- tysma and the deep fascia, the sterno-mastoid, sterno-hyoid and sterno- thyroid muscles, and a strong deep process of fascia from the inner border of the scalenus muscle. This part of the subclavian lies over the longus colli muscle, though at some distance from it, and separated from it by fat and nerves. Below the artery is the pleura, which ascends into the arch formed by the vessel. Veins. The innominate vein, and the ending of the subclavian C), form an arch below that of the artery. The large internal jugular vein crosses the arterial trunk close to the scalenus ; and underneath this vein, with the same direction, lies the vertebral vein. Much more superficial, and separated from the artery by muscles, is the deep part of the anterior jugu- lar vein. Nerves. In front of the artery lies the pneumogastric nerve, near to the internal jugular vein ; and inside this, the lower cardiac branch of the same nerve trunk. Behind the subclavian artery winds the recurrent branch of the [)neumogastric ; and still deeper is the cord of the sympa- thetic nerve with its cardiac branches, one or more of its offsets entwining round the vessel. Second part. Beneath the scalenus the vessel is less deep than when placed internal to that muscle, and at this spot it rises highest above the clavicle. The second part, like the first, is covered by the integuments, platysma, and deep fascia ; then by the clavicular origin of the st tuo- mastoideus ; and lastly by the anterior scalenus. Behind the vessel is the middle scalenus. Below the artery is the bag of the pleura, which ascends between the scalena. Veins. Below the level of the artery, and separated from it by the an- terior scalenus muscle, lies the arch of the subclavian vein. Nerves. In front of the scalenus descends the phrenic nerve. Above the vessel, in the interval between the scalena, are placed tlie large cervical nerves ; and the trunk formed by the last cervical and first dorsal is inter- posed between the artery and the middle scalenus. Third part. Beyond the scalenus the artery is contained in the clavicu- lar part of the posterior triangular sjjace (p. 64), and is nearer the surface than in the rest of its course : this part of the vessel is inclosed in a tube of the deep cervical fascia, which it receives as it passes from between the scaleni. It is comparatively superficial whilst in the space before men- tioned, for it is covered only by the integuments, the platysma, and deep fascia. ; but near its termination the vessel gets under cover of the suj)ra- scapular artery and vein, and the clavicle and subclavius muscle. In this SUBCLAVIAN ARTERY. 77 part of its course tlie artery rests on the surface of the first rib, which is interposed between it and the pleura. Veins. The arch of the subclavian vein is closfe to the artery, not being separated by muscle, but lies commonly at a lower level. The external jugular vein crosses it near the scalenus muscle ; and the suprascapular and transverse cervical branches, which enter the jugular, form sometimes a plexus over the third part of the artery. Nerves. Tlie' large cords of the brachial plexus are placed above and close to the vessel ; and the small nerve of the subclavius crosses it about the middle. Superficial to the cervical fascia lie the descending cutaneous branches of the cervical plexus. Pecaliaritles. The artery may spring as a separate trunk from the arch of the aorta ; and in such a deviation the vessel takes a deeper place than usual to reach the scaleni muscles. It has been before said (p. 66) that the subclavian may be in front of the scalenus or in its fibres ; and that it may be placed one inch and a half above the level of the clavicle. Branches of subclavian. Usually there are four chief branches on the subclavian artery. Three branches arise from the first part of the arterial trunk ; one (vertebral) ascends to the head ; another (internal mammary) descends to the chest; and the remaining one (thyroid axis) is a short thick trunk, which furnishes branches inwards and outwards to the thyroid body and shoulder. These arise commonly near the scalenus muscle, so as to leave an interval at the origin free from ofisets. This interval varies in length from half an inch to an inch in the greater number of cases ; and its extremes range from somewhat less than half an inch to an inch and three quarters. But in some instances the branches are scattered over the first part of the artery (Quain).^ The fourth branch (superior intercostal) arises beneath the anterior scalenus from the second part of the artery, and gives off the deep cervical branch ; a small spinal artery comes sometimes from this part of the trunk. If there is a branch present on the third part of tlie artery, it is com- monly the posterior scapular ; if more than one, this same branch with the external mammary ; and if more than two, an offset belonging to the thyroid axis will be added. The vertebral artery is generally the first and largest branch of the sub- clavian, and arises from the upper and posterior part. Ascending between the contiguous borders of the scalenus and longus colli muscles, this branch enters the aperture in the lateral mass of the sixth cervical vertebra, and is continued upwards to the skull through the foramina in the other cervical vertebrae. Before the artery enters its aperture it is partly concealed by the internal jugular vein, and passes beneath the thyroid artery ; it is ac- companied by branches of the sympathetic nerve, and supplies small mus- cular offsets. Its course and distribution will be given afterwards. The vertebral vein issues with its accompanying artery, to which it is superficial in the neck, and is directed over the subclavian artery to join tlie subclavian vein ; it receives the deep cervical vein, and the branch that accompanies the ascending cervical artery. The internal mammary branch leaves the lower part of the subclavian ' The student is referred for fuller information respecting the peculiarities of the vessel, and the practical applications to be deduced from them, to the original and valuable work on the Anatomy of the Arteries of the Human Body, by Richard Quain, F.R.S. 78 DISSECTION OF THE NECK. artery, and coursing downwards beneath the cLavicle, subchivius, and the riglit innominate vein, enters tlie thorax between tlie lirst rib and the bag of the pleura. As the artery disappears in the chest, it is crossed (super- ficially) by the phrenic nerve. The vessel is distributed to the walls of the chest and abdomen ; and its anatomy will be given with the dissection of those parts. Thyroid axis. This is a short thick trunk (fig. 10) which arises from the front of the artery near the anterior scalenus muscle, and soon divides into three branches — one to the thyroid body, and two to the sca{)ula. The suprascapular branch courses outwards across the lower part of the neck, behind the clavicle and subclavius muscle, to the superior costa of the scapula, and entering the supraspinal fossa is distributed on the dorsum of that bone. The connections of this artery are more fully seen in the dissection of the Back. The transverse cervical branch, usually larger than the preceding, takes a similar direction, though higher in the neck, and ends beneath the bor- der of the trapezius muscle in the superficial cervical and posterior scapular arteries. (" Dissection of the Back.") In its course outwards through the s[)ace containing the third part of the subclavian artery, this branch crosses the anterior scalenus, the phrenic nerve, and the brachial plexus. Some small offsets are supplied by it to the posterior triangular space of the neck. Though the transverse cervical artery supplies ordinarily the posterior scapular branch, there are many bodies in which it is too small to give origin to so large an offset. In such instances the diminished artery ends in the trapezius muscle ; whilst the posterior scapular branch arises sepa- rately from the third, or even the second part of the subclavian artery The inferior thyroid branch is the largest offset of the thyroid axis. Directed inwards with a flexuous course to the thyroid body, the branch passes beneath the common carotid artery and the accompanying vein and nerves, and in front of the longus colli muscle and the recurrent nerve. At the lower part of the thyroid body it divides into branches which ramify in the under surface, and communicate with the superior thyroid, and its fellow, forming a very free anastomosis between those vessels. Nea-r the larynx a laryngeal branch is distributed to that tube, and other offsets are furnished to the trachea. The ascending cervical branch of the thyroid is directed upwards be- tween the scalenus and rectus capitis anticus major, and ends in branches to those muscles and the posterior triangle of the neck. Some small spinal offsets are conveyed along the spinal nerves to the cord and its membranes. The veins corresponding with the branches of the thyroid axis have the following destination : those with the su[)rascapular and transverse cervical arteries oi)en into the external jugular vein. But the inferior thyroid vein begins in the tliyroid body, and descends in front of the trachea, beneath the muscles covering this tube, to the innominate vein. The superior intercostal artery arises from the posterior })art of the sub- clavian, and bends downwards over the neck of the first rib : its distribu- tion to the first two intercostal spaces will be seen in the thorax. Arising in common with this branch is the deep cervical artery (art. pro- funda cervicis). Analogous to the dorsal branch of an intercostal artery (Quain), it passes backwards between the transverse process of the last cervical vertebra and the first rib, lying internal to or beneath the two the ™ SUBCLAVIAN VEIN. 79 hinder scaleni muscles and the fleshy slips continued upwards from the erector spini«, to end beneath the complexus muscle at the posterior part of the neck. A spinal branch (Quain) is frequently given from the second part of the artery ; its offsets are continued into the spinal canal through the inter- vertebral foramina. The SUBCLAVIAN VEIN has not the same limits as the companion artery, reaching only from the lower edge of the first rib to the inner border of the anterior scalenus. It is a continuation of the axillary vein, and ends by joining the internal jugular in the innominate trunk. Its course is arched below tlie level of the artery, from which it is separated by the scalenus. The anterior and external jugular join the subclavian vein outside the scalenus, and the vertebral vein enters it inside that muscle. Into the angle of union of the subclavian and jugular veins the right lym[)hatic duct opens (fig. 27,^) ; and at the like spot, on the left side, the large lymphatic or thoracic duct ends (fig. 27,^). The highest pair of valves in the sub- clavian trunk is placed outside the opening of the external jugular vein.^ It should be borne in mind that not unfrequently the vein is as high in the neck as the third part of its companion artery ; and that the vein has been seen twice with the artery beneath the anterior scalenus. The ANTERIOR PRIMARY BRANCHES OF THE CERVICAL NERVES Spring from the common trunks in the intervertebral foramina, and appear on the side of the neck between the intertransverse muscles. These nerves are eight in number, and are equally divided between the cervical and the brachial plexus ; the highest four being combined in the former, and the remaining nerves in the latter plexus. The nerves receive offsets of com- munication from the sympathetic at their beginning, and intermix by means of numerous branches near the spine. To this general statement some addition is needed for the first two nerves ; and their peculiarities will be noticed in Section 18. Brachial Plexus. The four lower cervical nerves and part of the first intercostal are blended in this plexus; and a fasciculus is added to them from the lowest nerve entering the cervical plexus. Thus formed, the plexus reaches from the neck to the axilla, where it ends in nerves for the upper limb. Only the part of it above the clavicle can now be seen. In the neck the nerves have but little of a plexiform disposition : they lie at first between the scaleni muscles, opposite the four lower cervical vertebrae, and have the following arrangement: — The fifth and sixth nerves unite near the vertebrae ; the seventh remains distinct as far as the outer border of the middle scalenus ; and the last cer- vical and the piece of the first intercostal are blended in one trunk beneath the anterior scalenus ; so that they make at first three cords. Near the attachment of the middle scalenus to the rib, the seventh nerve throws itself into the trunk of the united fifth and sixth, and then there result two cords to the plexus: — the one (upper) formed by tlie fifth, sixth, and sev- enth cervical nerves; and the other (lower) by tlie eighth cervical and the first intercostal nerve. These two trunks accompany the subclavian artery, lying to its acromial side, and are continued to the axilla where they are more intimately blended. Branches. The branches of the plexus may be classed into those above ' See a paper on the Valves in the Veins of the Neck in the Edin. Med. Journal, of Nov., 1856, by Dr. Struthers. 80 DTSSECTIOX OF THE NECK. the clavicle, and tliose below that bone. The highest set end mostly in muscles of the lower part of the neck and of the scapula ; whilst tlie other set consist of the terminal branches, and are furnished to the upper limb, with which they will be referred to. Branches above the Clavice. The branch of the suhclaviiis mus- cle is a slender twig, which arises from the trunk formed by the fifth and sixth nerves, and is directed downwards over the subclavian artery to the under surface of the muscle ; it is often united with the phrenic nerve at the lower part of the neck. The branch of the rhomboid muscles springs from the fifth nerve in the substance of the middle scalenus, and perforates the fibres of that muscle; it is directed backwards beneath the levator anguli scapulie to its destina- tion. Branches are given usually from this nerve to the levator anguli scapulae. The nerve of the serratus (posterior thoracic nerve) is contained in the scalenus, like the preceding, and arises from the fifth and sixth nerves near the intervertrebral foramina. Piercing the fibres of the scalenus lower than the preceding branch, tlie nerve is continued behind the brachial plexus, and enters the serratus magnus muscle on the axillary surface. Branches of the scaleni and longus colli muscles. These small twigs are seen when the anterior scalenus is divided; they arise from the begin- ning of the trunks of the nerves. The suprascapular nerve is larger than either of the others. It arises near the subclavian branch from the cord of the plexus formed by the fifth and sixth nerves. Its destination is to the muscles on the dorsum of the scapula, and it will be dissected with tlie arm. Occasionally an offset from the fifth cervical trunk joins the phrenic nerve on the anterior scalenus muscle. The CERVICAL PLEXUS is formed by the first four cervical nerves. Situate at the upper part of the neck, it lies beneath the sterno-mastoid muscle, and on the middle scalenus and the levator anguli scapulae. It diflfers much from the brachial plexus, for it resembles a network more than a bundle of large cords. The following is the general arrangement of the nerves in the plexus : Each nerve, except the first, divides into an ascending and a descending branch, and these unite with similar parts of the contiguous nerves, so as to give rise to a series of arches. From these loops or arches the different branches arise: — The branches are superficial and deep. The superficial set has been described with the triangular space of the neck, as consisting of ascending and descending (p. 66). The ascending brandies may be now seen to spring from the union of the second andtliird nerves; and the descending, to take origin from the loop between the third and fourtli nerves. The deep set of branches remains to be examined : they are muscular and com- municating, and may be arranged into an internal and an external series. Internal Series The phrenic or muscular nerve of the diaphragm (fig. 16) is derived from the fourth, or third and fourth nerves of the plexus ; and it may be joined by a fasciculus fi-om the fifth cervical nerve. Descending obliquely on the surface of the anterior scalenus from the outer to the inner edge, it enters the chest in front of the internal mammary artery, but behind the subclavian vein, and traverses that cavity to reach the diaphragm. At the lower part of the neck the phrenic nerve is joined by a filament of the sympathetic, and sometimes by an ofliset of the nerve of the subclavius muscle. CERVICAL PLEXUS. 81 On the left side the nerve crosses over the first part of the subclavian artery. The branches communicating loith the descendens noni are two in num- ber. One arises from the second, and the other from the third cervical nerve ; they are directed inwards over the internal jugular vein, and com- municate in front of the carotid sheath with the descending muscular branch (descendens noni) of the hypoglossal nerve. Sometimes these nerves pass under the jugular vein. Muscular branches are furnished to the anterior recti muscles ; they arise from the loop between the first two nerves, and from the trunks of the other nerves close to the intervertebral foramina. Some connecting branches pass from the loop between the first two nerves, and unite with the sympathetic and some cranial nerves near the base of the skull: these will be afterw^ards described. External or Posterior Series. Muscular branches are given from the second nerve to the sterno-mastoideus ; from the third nerve to the levator anguli scapulas ; and from the third and fourth nerves to the trapezius. Further, some small branches supply the substance of the mid- dle scalenus. Connecting branches with the spinal accessory nerve exist in three places. First, in the sterno-mastoid muscle; next, in the posterior trian- gular space ; and lastly, beneath the trapezius. The union with the branches distributed to the trapezius has the appearance of a plexus. The COMMON CAROTID ARTERY is the leading vessel for the supply of blood to the neck and head (fig. 16, *). The origin of the vessel differs on opposite sides of the body, beginning at the lower part of the neck on the right, and in the thorax on the left side. The right vessel commences opposite the sterno-clavicular articulation in the bifurcation of the innominate artery, and ends at the upper border of the thyroid cartilage by dividing into the external and internal carotid. The course of the artery is along the side of the trachea and larynx, gradu- ally diverging from the vessel on the opposite side in consequence of the increasing size of the larynx; and its position will be marked by a line from the sterno-clavicular articulation to a point midAvay between the angle of the jaw and the mastoid process. Contained in a sheath of cervical fascia with the internal jugular vein and the pneumo-gastric nerve, the carotid artery has the following connec- tions w^ith the surrounding parts: — As high as the cricoid cartilage the vessel is deeply placed, and is concealed by the common coverings of the skin, platysma, and fasciae, and by the muscles at the low^er part of the neck, viz., sterno-mastoid (sternal origin), sterno-hyoid, omo-hyoid, and sterno-thyroid. But above the circoid cartilage to its termination the artery is less deep, being covered only by the sterno-mastoid with the common investments of the part. The vessel rests mostly on the longus colli muscle, but close to its ending on the rectus capitis anticus major. To the inner side of the carotid lie the trachea and larynx, the ojsophagus and pharynx, and the thyroid body, the last overhanging the vessel by the side of the larynx. Along the outer side of the carotid sheath is a chain of lymphatic glands. Veins. The large internal jugular lies on the outer side and close to the carotid at the upper end, but separated from it below by an interval of about half an inch : on the left side the vein is over the artery below^, as will be afterwards seen. One or two upper thyroid veins and their branches 6 82 DISSECTION OF THE NECK. cross the upper part of the arterial * trunk ; and opposite the thyroid body anotlier small vein (middle (thyroid) is directed back over the vessel. Near the clavicle the anterior jugular vein passes out under the sterno- mastoid : it is superficial to the artery, and separated from it by the sterno- hyoid and thyroid muscles. Arteries. Offsets of the upper thyroid artery descend over the top of the sheath ; and the inferior thyroid crosses under it below the level of the cricoid cartilage. Nerves. The descendens noni lies in front of the sheath, crossing from the outer to the inner side, and is joined there by the cervical nerves. The pueumogastric lies within the sheath, behind and between the artery and the vein. The sympatlietic cord and branches rest on the spine behind the sheath. All the nerves above mentioned have a longitudinal direction; but the inferior laryngeal or recurrent crosses obliquely inwards behind the sheath towards the lower end of the artery. Branches of carotid. As a rule, the common carotid artery does not furnish any collateral branch, though it is very common for the superior thyroid to spring from its upper end. At the terminal bifurcation into the two carotids the artery is slightly bulged. The INTERNAL JUGULAR VEIN cxtcuds upwards to the base of the skull, but only the part of it that accompanies the common carotid is now seen. Placed behind or external to its artery, the vein ends below by uniting with the subclavian in the innominate vein. Its proximity to the carotid is not equally close throughout, for at the lower part of the neck the vein inclines backwards, leaving a space between it and the artery, in which the vagus nerve is seen about midway between the two. Sometimes the vein is superficial to the carotid, as on the left side. The lower part of the vein is marked by a dilatation or sinus. Near its ending it becomes contracted, and is provided with a pair of valves (Struthers). In this part of its course the vein receives the superior and middle thy- roid branches. Peculiarities of the carotid. The origin of the artery on the right side may be above or below the point stated. Mention has been made of the difference in the place of bifurcation, and of the fact that the common carotid may not be divided into two (p. 70). Instead of one, there may be two trunks issuing from beneath the hyoid muscles. Dissection. The dissector may next trace out completely the trunk of the external carotid (fig. 17), and follow its branches until they disappear beneath different parts. Afterwards he may separate from one anotlier the digastric and stylo-hyoid muscles, which cross the carotid ; and may define their origin and insertion. The DIGASTRIC MUSCLE (fig. 15^) cousists of two fleshy bellies, united by an intervening tendon, whence its name. The posterior, the larger of the two, arises from the groove beneath the mastoid process ; wliilst the anterior belly is fixed on the side of the sym[)hysis of the lower jaw. From these attachments the fibres are directed to the intervening tendon, which is surrounded by fibres of the stylo-hyoideus, and is united to its fellow, and to the body and part of the great cornu of the os hyoides by an aponeurotic expansion. The arch formed by the digastric is superficial, except at the outer end, where it is beneath the sterno-mastoid and s[)lenius muscles. The poste- rior belly covers the carotid vessels and the accompanying veins and DISSECTION OF THE NECK. 83 nerves ; and is placed across tlie anterior triangular space of the neck* in the position of a line from the mastoid process to a little above the hyoid bone : along its lower border lie the occipital artery and the hypoglossal nerve ; the former passing backwards, the latter forwards. The anterior belly rests on the mylo-hyoid muscle. The muscle forms the lower boundary of a space between the jaw and the base of the skull, which is subdivided into two by the stylo-maxillary ligament. In the posterior portion are contained the parotid gland (^"j, and the vessels and nerves in connection with it (p. 41) ; in the anterior, are the submaxillary gland ("), w^ith the facial and submental vessels, and deeper still, the muscles between the chin and the hyoid bone. Action. The lower jaw being movable, the muscle depresses that bone and opens the mouth. If the jaw is fixed, the two bellies acting will ele- vate the hyoid bone. It is supposed that the posterior belly may assist in moving back the head when the jaw is fixed. The STYLO-HYOiD MUSCLE is thin and slender, and has the same posi- tion as the posterior belly of the digastric. It arises from the outer sur- face of the styloid process, near the base, and is inserted into the body of the OS hyoides. The muscle has the same connections as the posterior belly of the digas- tric ; and its fleshy fibres are usually perforated by the tendon of that muscle. In some bodies the stylo-hyoideus is absent. Action. This muscle elevates the os hyoides preparatory to swallowing, and checks, with the posterior belly of the digastric, the too forward move- ment of that bone by the otiier elevators. The HYPOGLOSSAL NERVE (ninth cranial) appears in the anterior tri- angle at the lower edge of the digastric muscle, where it hooks round the occipital artery; it is then directed forwards to the tongue below that muscle, and disappears in front beneath the mylo-hyoideus. In this course the nerve passes over the two carotids ; and near the cornu of the os hyoides it crosses also the lingual artery, so as to become higher than the vessel. From this part arise the descendens noni branch, and a small muscular offset to the thryo-hyoideus. The descending branch (ram. descend, noni) leaves the trunk of the hypoglossal on the outer side of the carotid artery, and descends on the front of (sometimes in) the sheath of the vessel to about the middle of the neck, where it is joined by the communicating branches of the cervical nerves. After the union of the spinal nerves, offsets are su{)plied to the depressor muscles of the os hyoides, viz., omo-hyoid (both bellies), sterno- hyoid, and sterno-thyroid : sometimes another offset is continued to the thorax, wiiere it joins the phrenic and cardiac nerves. The connection between the descendens noni and the spinal nerves is formed by two or more cross filaments, so as to construct an arch with the concavity upwards ; and an interchange of fibrils between the two nerves is supposed to take place. The EXTERNAL CAROTID ARTERY (fig. 17, d) spHngs from the bifurca- tion of the common carotid at the upper border of the thyroid cartilage, and furnishes branches to the neck, the face, and the outer parts of the head. From the place of origin it ascends in front of the mastoid process, and ends near the condyle of the jaw in the internal maxillary and temporal branches. The artery lies at first to the inner side of the internal carotid, but 84 DISSECTION OF THE NECK it afterwards becomes superficial to that vessel ; and its direction is some- what arched forwards, though the position would be marked sufficiently by a line from the front of tlie meatus of the ear to the cricoid cartihige. At first the external carotid is overlaid by the sterno-mastoideus, and by the common coverings of the anterior triangular space, viz., the skin, and the superficial and deep fascia with the platysma. But above the Fig. 17. ExTBKKAL Carotid and its Superficial Branches ("Anatomy of the Arteries," Quain). a. Common carotid. m. Supra-orbital. b. Internal jugular vein. n. External nasal. c. Internal carotid. o. Angular branch of facial. d. External carotid. V- Lateral nasal. e. Upper thyroid branch. r. Superior coronary. /. Lingual. s. Inferior coronary. g. Facial. t. Inferior labial. h. Internal maxillary. u. , Submental artery. i. Superficial temporal. level of a line from the mastoid process to the hyoid bone, the artery is crossed by the digastric and stylo-hyoid muscles, and still higher the 2)arotid gland conceals it. At its beginning the artery rests against the pharynx ; but above the angle of the jaw it is placed over the styloid process and stylo-pharyngeus muscle, wliich separates it from the internal carotid. To the inner side of the vessel at first is the pharynx ; and still higher, are the ramus of the jaw and the stylo-maxillary ligament. EXTERNAL CAROTID ARTERY. 85 Veins. There is not any companion vein with the external carotid as witli most arteries ; but sometimes a vein, formed by the union of the tem- poral and internal maxillary branches (p. 42), will accompany it. Near tlie beginnino; it is crossed by the facial and lingual branches joining the internal jugular vein ; and near the ending the external jugular vein lies over it. Nerves are directed from behind forwards over and under the artery. At the lower border of the digastric muscle the hypoglossal lies over the vessel, and near tlie ending the ramifications of the facial nerve are super- ficial to it. Three nerves lie beneath it : beginning below, the small ex- ternal laryngeal ; a little higher, the superior laryngeal ; and near the base of the jaw, the glosso-pharyngeal. Tlie branches of the external carotid are numerous, and are classed into an anterior, posterior, and ascending set. The anterior set comprise branches to the thyroid body, the tongue, and the face, viz., superior thy- roid, lingual, and facial arteries. In the posterior set are the occipital and ]iosterior auricular branches. And the ascending set include the as- cending pharyngeal, temporal, and internal maxillary arteries. Besides these, the carotid gives other branches to the sterno-mastoid muscle and the ]mrotid gland. Tlie origin of the branches of the carotid may be altered by their closer aggregation on the trunk. The usual number may be diminished by two or more uniting into one ; or the number may be increased by some of the secondary offsets being transferred to the parent trunk. Directions. All the branches, except the ascending pharyngeal, lingual, and internal maxillary, may be now examined ; but those three will be described afterwards with the regions they occupy. The superior thyroid artery (e) arises near the cornu of the os hyoides, and passes beneath the omo-hyoid, sterno-hyoid, and sterno-thyroid mus- cles to the thyroid body, to w^hich it is distributed on the anterior aspect. This artery is superficial in the anterior triangle, and furnishes offsets to the lowest constrictor and the muscle beneath which it lies, in addition to the following named branches : — a. The hyoid branch is very inconsiderable in size, and runs inwards below the hyoid bone : it supplies the muscles attached to that bone, and anastomoses with the vessel of the opposite side. b. A branch for the sterno-mastoid muscle lies in front of the sheath of the common carotid artery, and is distributed chiefly to the muscle from which it takes its name. c. The laryngeal branch pierces the membrane between the hyoid bone and the thyroid cartilage, with the superior laryngeal nerve, and ends in the interior of the larynx. d. A small crico-thyroid branch is placed on the membrane between the cricoid .and the thyroid cartilage, and communicates with the corresponding artery of the opposite side, forming an arch. The superior thyroid vein commences in the larynx and the thyroid body, and crosses the end of the common carotid artery to open into the internal jugular vein. The facial artery (g) arises above the lingual, and is directed upwards over the lower jaw to the face. In the neck the artery passes beneath the digastric and stylo-hyoid muscles, and is afterwards lodged on the sub- maxillary gland, on which it makes a sigmoid turn. Its anatomy in the hU DISSECTION OF THE NECK. face has been examined (j). 40). From the cervical part branches are given to the pharynx, and to tlie structures below the jaw, viz. : — a. Tiie inferior palatine branch ascends to the j)harynx beneath the jaw, passing between the stylo-glossus and stylo-pharyngeus muscles, and is distributed to the soft ])alate, after furnishing a brancli to the tonsil. This branch frequently arises from the ascending })haryngeal artery. 6. The tonsillar branch is smaller than the preceding, and passes be- tween the internal pterygoid and stylo-glossus muscles. Opj)Osite the ton- sil it perforates the constrictor muscle, and ends in offsets to that body. c. Glandular branches are supplied to the submaxillary gland from the part of the artery in contact with it. d. The submental branch arises near the inferior maxilla, and courses forwards on the mylo-hyoideus to the anterior belly of the digastric muscle, where it ends in offsets : some of these turn over the jaw to the chin and lower lip ; and the rest supply the muscles between the jaw and the hyoid bone — one or two perforating the mylo-hyoideus and anastomosing with the sublingual artery. Thoi facial vein (p. 40) joins the internal jugular. In the cervical part of its course it receives branches corresponding with the offsets of the artery. It often throws itself into the temjjoro-maxillary trunk. The occipital artery is of considerable size, and is destined for the back of the head. It arises from the carotid opposite the facial branch, near the lower border of the digastric muscle, and ascends to the inner part of the mastoid process of the temporal bone. Next it turns horizontally backwards on the occipital bone, passing above the transverse process of the atlas ; and finally becomes cutaneous near the middle line (p. 21). In the neck this artery passes beneath the digastric muscle and a part of the parotid gland ; and crosses over the internal carotid artery, the jugular vein, and the spinal accessory and liypoglossal nerves. The only ofJ'set from the artery in the front of the neck is a small poste- rior meningeal branch: this ascends along the internal jugular vein, and enters the skull by the foramen jugulare (p. 30). The branches at the back of the neck will be afterwards seen. The occipital vein begins at the back of the head (p. 21), and has the same course as the artery ; it communicates with the lateral sinus through the mastoid foramen, also with the diploic veins, and coalesces with the in- ternal (sometimes the external) jugular vein. The posterior auricular artery is smaller than the preceding branch, and takes origin above the digastric muscle. Between the ear and the mastoid process, it divides into two branches for the ear and occiput (p. 21). A small branch, stylo-mastoid enters the foramen of the same name, and supplies the tympanum of the ear. The vein with the artery receives a stylo mastoid branch, and terminates in the trunk formed by the temporal and internal maxillary veins. The temporal artery (?) is in direction the continuation of the external carotid trunk, and is one of the terminal branches of that artery. As- cending under the parotid gland it divides on the temporal fascia into an- terior and posterior branches, about two inches above the zygoma ; these are distributed to the front and side of the head (p. 21). The trunk of the artery gives offsets to the surrounding [)arts, viz. : — a. Parotid branches are furnislied to the gland of the same name. Articular twigs are supplied to the articulation of the lower jaw ; and MASSETER MUSCLE. 87 Other muscular branches enter the masseter. Some anterior auricular offsets are distributed to the pinna and meatus of the external ear. h. The transverse facial branch quits the temporal artery opposite the condyle of the jaw, and is directed forwards over the masseter muscle (p. 41) ; on the side of the face it supplies the muscles and integuments, and anastomoses with the facial artery. c. The middle temporal branch arises just above the zygoma, and pierces the temporal aponeurosis to enter the substance of tlie temporal muscle : it anastomoses with branches of the internal maxillary artery. d. A small branch of the temporal artery is likewise found between the layers of the temporal fascia ; this anastomoses with an offset of the lachry- mal. The temporal vein commences on the side of the head (p. 21) and is con- tiguous to its companion artery. Near the zygoma it is joined by the middle temporal vein ; next it receives branches which are companions of the offsets of the artery ; and it ends by uniting with the internal maxil- lary vein. Directions. The lower part of the neck w^ill not be used again for some days, so that the dissector may stitch together the flaps of skin, when he has applied salt to preserve it. Section VI. PTERYGO-MAXILLARY REGION. In this region are included the muscles superficial to and beneath the ramus of the lower jaw, together with the articulation of that bone. In contact with the muscles (pterygoid) beneath the jaw, are the internal maxillary bloodvessels, and the inferior maxillary trunk of the fifth nerve. Dissection. The masseter muscle, which is superficial to tlie bones, has been ])artly laid bare in the dissection of the facial nerve. To see it more fully tlie branches of the facial nerve, and the transverse facial artery should be cut through, and turned backwards oif the face. A little cleaning will suffice to define the origin and insertion of the muscle. Should there be any tow or cotton wool in the mouth let it be removed. The MASSETER (fig. 6, ^") is partly aponeurotic at the upper attachment. It arises from all the lower border of the zygomatic arch, extending for- wards to the upper jaw ; and from the inner surface of the arch by fine fleshy fibres. Most of the fibres are inclined down and somewhat back, and are inserted into the outer surface of the coronoid process, ramus, and angle of the lower jaw ; but a few are fixed into the contiguous part of the body of the bone as far as the second molar tooth. Some of the hinder and deeper fibres are inclined downwards and forwards across the others. The lower part of the masseter is subcutaneous, but the upper is partly concealed by the parotid gland (socia parotidis), and is crossed by Sten- son's duct, and by the transverse facial vessels and the facial nerve. The anterior border projects over the buccinator muscle, and a quantity of fat resembling that in the orbit is found beneath it. The muscle covers the 88 DISSECTION OF THE PTERYGOID REGION- ramus of the jaw, and the masseteric branches of nerve and arterj enter- ing it at the under surface. Action. It raises the lower jaw with the internal pterygoid in the mas- tication of the food. Dissection. To lay bare the temporal muscle to its insertion, the follow- ing dissection may be made : Tiie temporal fascia is to be detached from tiie upper border of the zygomatic arch, and to be removed from the sur- face of the muscle. Next, the arch of the zygoma is to be sawn through in front and behind, so as to include all its length ; and is to be tlirown down (without being cut off) with the masseter muscle still attached to it, by separating the fibres of that muscle from the ramus of the jaw. In detaching the masseter muscle, its nerve and artery, which pass through the sigmoid notch, will be found. The surface of the temporal muscle may be then cleaned ; and to ex- pose its insertion and deep origin, let the coronoid process be sawn off by a cut passing from the centre of the sigmoid notch nearly to the last molar tooth, so as to include the whole insertion of the muscle. Before sawing tlie bone let the student find and separate from the muscle the buccal ves- sels and nerve issuing from beneath it. Lastly, the coronoid process sliould be raised and the fat removed, in order that the lower fibres of the tem- poral muscle, and their contiguity to the external pterygoid close below them, may be observed. The temporal muscle (fig. 18, ^) takes its origin from the whole of the temporal fossa (p. 20), reaching up to the semicircular line on the side of the skull, and downwards to the crest on the outer aspect of the great wing of the sphenoid bone. From this extensive attachment, as well as from the fascia over it, the fibres converge to a superficial tendon, which is inserted into the inner surface of the coronoid process, as well as into a groove on the same process which reaches from the apex to near the last molar tooth. Behind the posterior border of the tendon are the masseteric vessels and nerve, and in front of it the buccal vessels and nerve : the last nerve per- forates occasionally some of the fibres of the muscle. Action. All the fibres contracting the muscle will raise the mandible and press it forcibly against the upper jaw ; but the hinder fibres may re- tract the lower jaw after it has been moved forwards by the external ptery- goid. Dissection. For the display of the pterygoid muscles (fig. 18), it will be necessary to remove a piece of the ramus of the jaw. But the greater part of the temjjoral muscle is to be first detached from the subjacent bone with the handle of tlie scalpel, and the deep temporal vessels and nerves are to be sought in its fibres. A piece of the ramus is next to be taken away by sawing across the bone close to the condyle, and again close above the dental foramen ; and to make the dental vessels and nerve in contact with its inner surface secure from injury, the luuulle of the scalpel may be inserted between them and the bone, and carried downwards to their entrance into the foramen. The masseteric artery and nerve are liable to be cut in sawing the bone ; should these be divided, turn them upwards for the present, and afterwards tie together the ends. After the loose piece of l)one has been removed, and the subjacent parts freed from much fat, the pterygoid muscles will appear, — the external (^) being directed outwards to the condyle of the jaw, and the internal (''), wliich is parallel in direction to the masseter, being inclined to the angle POSITION OF VESSELS AND NERVES. 89 of tlie jaw. In removing the fatty tissue, the student must be careful not to take away the thin lateral ligament, which lies on the internal pterygoid muscle beneath the ramus. Position of vessels. Crossing inwards over the external pterygoid muscle, is the internal maxillary artery, which distributes offsets upwards Superficial View of the Pterygoid Region (Quain's "Arteries"). 1. Temporal muscle. 2. Extei'nal pterygoid. .3. Internal pterygoid. 4. Buccinator. 5. Digastric and stylo-hyoid muscles cut and thrown back. Common carotid dividing into external and internal trunks. 8. Internal maxillary artery (beneath the pterygoid instead of over it) and its branches. The nerves are omitted in this woodcut. and downwards: sometimes the artery will be placed beneath the muscle. The veins with the artery are large and plexiform : and may be taken away. Position of nerves. Most of the branches of the inferior maxillary nerve appear in this dissection. Thus, issuing from beneath the lower border of the external pterygoid are the large dental and gustatory nerves, the latter being the more internal of the two; and coming out behind the joint of the jaw is the auriculo-temporal nerve. Appearing between the upper border of the muscle and the cranium, are tlie small masseteric and deep temporal nerves. Tlie buccal branch of the nerve perforates tlie fibres of the same muscle near the inner attachment. Branches of the above- mentioned artery accompany the nerves. Coursing along tlie posterior part of the upper jaw, is the small posterior dental nerve with an artery. Between the jaws is the whitish narrow band of the pterygo-maxillary ligament, to which the buccinator and superior constrictor muscles are connected. The EXTERNAL PTERYGOID MUSCLE (fig. 18, ^) cxtcuds almost horizon- tally from the zygomatic fossa to the neck of the lower jaw. Its origin is 90 DISSECTION OF THE PTERYGOID REGION. from the outer surface of the great wing of the sphenoid bone below the crest, and from the outer surface of the external pterygoid plate. The fibres are directed outwards and somewhat backwards, those attached to the upper margin of the spheno-maxillary fissure forming at first a separate bundle, and are inserted into the hollow in front of the neck of the lower jaw bone, and into the interarticular fibro-cartilage of the joint. Externally the pterygoid is concealed by the temporal muscle and the lower jaw, and the internal maxillary artery lies on it. By the deep sur- face it is in contact with the inferior maxillary nerve, with a plexus of veins, and with the internal lateral ligament of tlie joint of the jaw. The parts in contact with the borders of the muscle have been enumerated before. Sometimes the slip of the muscle, which is attached to the margin of tlie spheno-maxillary fissure and the root of the external pterygoid plate, is described as a separate head with an insertion into the interarticular car- tilage. Action. If both muscles act the jaw is moved forwards, so that the lower dental arch is placed in front of the upper, and the grinding teeth are rubbed together in an antero-posterior direction. In order that the lower front teeth may be able to pass the others the jaw is depressed. One muscle contracting (say the right), the condyle of the same side is drawn inwards and forwards, and the grinding teeth of the lower jaw are moved horizontally to the left across those oF the upper. By the alternate action of the two muscles the trituration of tlie food is effected. The INTERNAL PTERYGOID MUSCLE (fig. 18, ') is nearly parallel to the ramus of the jaw, and its fibres are longer than those of the preceding muscle. Arising in the pterygoid fossa, and chiefly from the inner sur- face of the external pterygoid plate, the nmscle is further attached below, outside the fossa, to the outer surface of the tuberosity of the palate bone, and to the tuberosity of the upper jaw bone. The fibres descend to be inserted into the angle, and into the inner surface of the ramus of the jaw as high as the inferior dental foramen. On tlie muscle are placed the dental and gustatory nerves, the dental artery, and the internal lateral ligament of the jaw. The deep surface is in relation below with the superior constrictor, and at its origin with the tensor palati muscle. Action. From the direction and attachment of the fibres the muscle will unite with the masseter in elevating the jaw. Directions. Before proceeding further in the dissection, the student may learn the anatomy of the articulation of the lower jaw. TEMroRO-MAXiLLARY ARTICULATION. In tliis articulation are com- bined the condyle of the jaw and the anterior part of the glenoid fossa of the temporal Ixme ; but the osseous surfaces are not in contact, for a piece of fibro-cartilage with two synovial sacs is interposed between them. The bones are retained in apposition mostly by the strong muscles of the lower jaw ; but the following ligaments serve to unite them. Capsule. This is a thin fibrous tube inclosing the bones, and is wider above than below. By the upper end it is fixed around the articular surface of the temporal bone in front of the Glaserian fissure ; and it is in- serted below around the condyle of the lower jaw. The space in the interior is divided into two, u{)per and lower, by a piece of fibro-cartilage, which is united to the capsule l)y its circumfennice. The external lateral is a short ligamentous band, being but a part of the TEMPORO-MAXILLARY JOINT. 91 capsule, which is attached above to the tubercle at the root of the zygoma, and below to the outer side of the neck of the inferior maxilla. The internal lateral ligament (fig. 19, ^) is a long, thin, membranous band, which is not in contact with the joint. Su[>eriorly it is connected to a projection inside the glenoid fossa, which consists of the spinous pro- cess of the sphenoid and the vaginal process of the temporal bone ; and inferiorly it is inserted into the orifice of the dental canal in the lower jaw. The ligament lies between the jaw and the internal pterygoid ; and its origin is concealed by the external pterygoid muscle. Between the liga- ment and the jaw the internal maxillary artery intervenes. Fis:. 19. Fig. 20. Ligaments of the Jaw — ax isxer view (Bonrgery and Jacob). 1. Internal lateral ligament. 2 Stylo-maxillary. 3. Stylo-maxillary ligament. A VIEW OP THE IXTBKIOR OF THE COMPOrXD Tempoko-maxillabt Joist (Bourgery and Jacob) . 4. Interarticular fibro-cartilage — the dark inter- vals above and below are the hollows con- taining the synovial membranes. Dissection. After the external lateral ligament and the capsule of the joint have been examined, an interarticular fibro-cartilage, with a hollow above and below it, will be exposed by taking away the capsule on the outer side (fig. 20). The interarticular Jihro-cartilage (fig. 20, *) is adapted to the surfaces of the bones. It is elongated transversely, is thinner in the centre than at the margins, and an aperture is sometimes present in the middle. The upper surface fits into the glenoid fossa, being concavo-convex from before backwards, and the lower is moulded on the convexity of the condyle of the jaw. By the circumference it is connected with the capsule and the external lateral ligament ; and in front the external pterygoid muscle i3 attached to it. This interarticular pad allows greater freedom of movement in the joint without dislocation ; diminishes the injurious effect of pressure ; and dead- ens the sound of the jaw striking the skull. Two synovial membranes are present in the articulation — one above, and one below the fibro-cartilage. The lower one is the smaller of the two. Another structure — the stylo-maxillary ligament (fig. 20, ') is described as a uniting band to this articulation. It is a process of the deep cervical fascia, which extends from the styloid process to the hinder part of the ramus of the jaw: it gives attachment to the stylo-glossus muscle, and separates the parotid and submaxillary glands. 92 DISSECTION OF THE PTERYGOID REGION. Articular surfaces of the bones. The lower jaw possesses a thin narrow condyle, which is elongated transversely, and directed backwards and inwards. On the temporal bone is a narrow deep articular hollow (glenoid fossa), which is lengthened from without in, and is placed in front of the Glaserian fissure. In front of this is a prominence of bone (transverse root of the zygomatic process), which is convex from before back and rather hollowed from side to side. Movements of the joint. This condyloid articulation is provided with an up and down, a to and fro, and a lateral movement. In depressing the jaw, as in opening the mouth, the articular condyle moves forwards till it is placed under the convexity at the fore part of the articular hollow, but the interposed concave fibro-cartilage gives security to the joint. Even with this provision, a slight degree more of sudden motion throws the condyle off the prominence of the temporal bone into the zygomatic fossa, and gives rise to dislocation. In this movement the fore and lateral parts of the capsule are made tight ; and the fibro-cartilage is drawn forwards with the condyle by the external pterygoid muscle. When the jaw is elevated and tlie mouth closed, the condyle and the fibro-cartilage glide back into the glenoid fossa. In this position the jaw is placed in the state of greatest security against dislocation. The ligaments and the surrounding muscles, which were stretched in the previous movement, are then set at rest. ^ During the horizontal motion forwards and backwards the condyle is moved successively to the front and back of the temporal articular surface ; and the lower jaw is slightly depressed, in order that the fore teeth in the upper dental arch should not im[)ede those of the lower. By turns the front and back of the ca[)sule will be stretched; and the fibro-cartilage always follows the condyle of the jaw, even in dislocation. Too great motion forwards will be prevented by the coronoid process of the jaw striking against the zygomatic arch ; and that backwards, by the meeting of the condyle and the auditory process of the os temporis. Lateral horizontal movement puts tlie jaw first to one side and then to the other. When the jaw is forced to the left side, the right condyle sinks into its articular hollow, whilst the left is projected ; and the grinding teeth of the lower dental arch are moved to the left across those of the upper. By the alternate action to opposite sides the food is triturated. The inner part of the capsule on the right, and the outer part on the left side, will be put on the stretch when the jaw is carried to the left of the middle line ; and the opposite. With old edentulous jaws the capsule is much enlarged, and permits the condyle to wander backwards behind the Glaserian fissure. Without this provision the altered lower jaw would not meet the upi)er to crush the food. Dissection. The condyle of the jaw is next to be disarticulated, the external pterygoid muscle being still uncut; and it with the attached mus- cle is to be drawn forwards so as to allow tlie fifth nerve to be seen. Whilst cutting through the joint capsule, the dissector must be careful of the auriculo-tem})oral nerve close beneath (fig. 21). On drawing forwards the j)terygoid muscle, and removing some fat, the dissector will find the trunk of the inferior maxillary nerve. All the small muscular branches of the nerve before noted should be traced to the trunk in the foramen ovale of the sphenoid bone. The auriculo-temporal branch INTERNAL MAXILLARY ARTERY. 93 should be followed backwards with care behind the articulation, and the dental and gustatory nerves beneath the muscle should be cleaned. The small cliorda tympani is then to be found joining the posterior part of the gustatory nerve near the skull. The middle meningeal artery is to be sought beneath the external ptery- goid. Sometimes the trunk of the internal maxillary artery lies beneath that muscle, and in such case, it and its branches are to be traced out. The INTERNAL MAXILLARY ARTERY (fig. 17, h) IS onc of the terminal branches of the external carotid, and takes a winding course beneath the lower jaw and the temporal muscle to the spheno-maxillary fossa, where it ends in branches for the face, the interior of the nose, and the palate and pharynx. At first the artery is directed inwards beneath the jaw, between that bone and the internal lateral ligament of the joint, and crosses the dental nerve. Next, the vessel winds over the external pterygoid muscle, being placed between it and the temporal muscle. And lastly, the artery enters the spheno-maxillary fossa between the processes of origin of the external pterygoid. The course of the artery is sometimes beneath, instead of over the external pterygoid : in such a state the artery gains the spheno-maxil- lary fossa by coming upwards through the origin of the muscle, as in the woodcut. The branches of this artery are very numerous, and are classed into three sets : thus one set arises beneath the jaw ; another between the mus- cles ; and another in the spheno-maxillary fossa. Two branches, viz., the inferior dental and middle meningeal, leave the internal maxillary artery whilst it is in contact with the ramus of the jaw. The inferior dental branch descends between the internal lateral liga- ment and the jaw, and enters the foramen on the inner surface of the ramus, along with the dental nerve : it supplies the teeth, and ends in the lower part of the face. As this artery is about to enter the foramen it furnishes a small twig, mylo-hyoid branch, to the muscle of that name ; this is conducted by a groove on the inner surface of the bone, in company with a branch from the dental nerve, to the superficial surface of the mylo-hyoid muscle, where it anastomoses with the submental artery. The great yneningeal artery is the largest branch, and arises opposite the preceding. It ascends beneath the external pterygoid muscle, and (oftentimes) between the roots of the auriculo-temporal nerve ; crossing the internal lateral ligament, it enters the skull through the foramen spino- sum of the sphenoid bone. When in the skull the artery ascends to the vertex of the head, and supplies the bone and the dura mater (p. 29). Before the meningeal artery enters the skull, it furnishes the following small branches : — a. The tympanic branch (inferior) passes into the tympanum through the Glaserian fissure, and is distributed to the membrana tympani and that cavity. b. A deep auricular branch arises with the former or separately enters the meatus through the cartilage, or between this and the bone, and rami- fies in the meatus and on the membrana tympani. c. The small meningeal branch begins near the skull, and courses through the foramen ovale with the inferior maxillary nerve; it ramifies in the dura mater in the middle fossa of the skull. Another small branch springs from the dental artery or the internal 94 DISSECTION OF THE PTERYGOID REGION. maxillary trunk, and accompanying tlie gustatory nerve, ends in the cheek and the mucous membrane of tlie mouth. The branches from the second part of tlie artery, viz., whilst it is between the temporalis and pterygoideus externus are distributed to the temporal, masseteric, buccal, and pterygoid muscles. The deep temporal arteries are two in number (anterior and posterior) ; and each occupies the part of the tem[)oral fossa indicated by its name. They ascend beneath the temporal muscle, and anastomose with the super- ficial temporal artery : the anterior communicates, through the malar bone, with branches of the lachrymal artery. When the parent trunk has the unusual position beneath the pterygoid, the anterior branch lies under that muscle, instead of over it. The masseteric artery is directed outwards with the nerve of the same name behind the tendon of the temporal muscle ; and passing through the sigmoid notch, enters the under surface of the masse ter muscle. Its branches anastamose with the other offsets to the muscle from the external carotid trunk. The buccal branch quits the artery near the upper jaw, and in the un- usual position of tlie artery it may perforate the fibres of the pterygoid ; it descends beneath the coronoid process with its companion nerve, and is distributed to the buccinator muscle, the cheek, and the side of the face, joining the branches of the facial artery. Tha pterygoid branches are uncertain in their position; w^hether derived from the trunk or some of the branches of the internal maxillary, they enter both pterygoid muscles. Of the branches that arise from the artery when it enters the spheno- maxillary fossa, only one, the superior dental, will be now described. The remainder will be examined with the superior maxillary nerve and Meckel's ganglion ; they are infraorbital (p. 105), superior palatine, naso-palatine, vidian, and pterygo-palatine (Section 14). The superior or posterior dental branch takes origin near the top of the upper maxilla, and descends with a tortuous course on the outer surface of that bone, along with a small branch of the superior maxillary nerve. It sends twigs into the foramina in the bone, and supplies the upper molar and bicuspid teeth ; but some external offsets are furnished to the gums. A few branches reach the lining membrane of the antrum. The INTERNAL MAXILLARY VEIN rcccive the offsets accompanying the branches of the artery in the first two parts of its course : these veins form a plexus — pterygoid, between the two pterygoid muscles, and in part be- tween the temporal and external pterygoid muscles. This anastomosis communicates with the alveolar plexus ; with the facial vein by a large branch (anterior internal maxillary) ; and with the cavernous sinus in the interior of the skull, by veinules that pass through the base of the cranium. Escaping from the plexus, the vein accompanies the artery to the paro- tid gland, and there joins the superficial tem[)oral vein, — the union of the two giving rise to the external jugular. Sometimes this common vessel enters the internal jugular vein (p. 42). The INFERIOR MAXILLARY NERVE (fig. 21) is the largest of the three trunks arising from the Gasserian ganglion (p. 32). It leaves the skull by the foramen ovale in the sphenoid bone, and divides beneath the ex- ternal pterygoid muscle into two chief pieces, viz., an anterior, small, moto- sensory part ; and a large, posterior, chiefly sensory portion. INFERIOR MAXILLARY NERVE, 95 Directions. Should the internal maxillary artery obstruct the view of the nerve, it may be cut through. The SMALLER PART, formed mainly by its contribution from the trunk of the nerve, receives nearly all the fibrils of the motor root, and ends in branches for the muscles of the jaw, viz., temporal, masseter, and one ptery- goid ; and for the muscle of the cheek, the buccinator. Fig. 21. Muscles : — a. Temporal reflected. 6. Condyle of the jaw disarticulated with the external pterygoid attached to it. c. Internal pterygoid. d. Buccinator. /. Massi ter thrown down. Nerves : — 10. Dekp view of the Pterygoid Keqion (Illustra- tions of Dissections). Buccal. Masseteric, cut. Deep tcmpoi-al. Auriculo-temporal. Chorda tympani. Inferior dental. Gustatory. Internal lateral ligament of the lower jaw. The arteries are not figured, with the exception of the internal maxillary trunk which is marked with 9 : the offsets of the artery ac- company the nerves, being named like them. The deep temporal branches (^) are furnished to the under surface of the temporal muscle. Like the arteries, they are two in number, anterior and posterior, and course upwards beneath the external pterygoid muscle. The posterior branch is the smallest, and is often derived from the masseteric nerve ; it is placed near the back of the temporal fossa. The anterior branch supplies the greater part of the muscle, and com- municates sometimes with the buccal nerve. The masseteric branch (^) takes a backward course above the external pterygoid muscle, and through the sigmoid notch, to the under surface of the masseter muscle : in the masseter the nerve can be followed to near the anterior border. As this branch passes by the articulation of the jaw it gives one or more twigs to that joint. The pterygoid branches come from both parts of the inferior maxillary nerve. The branch or branches to the external pterygoid spring from the small part, or from the buccal nerve, and enter the under surface of its muscle. The nerve to the internal pterygoid arises from the large part of the maxillary trunk close to the skull, and may be followed beneatli the upper border to the deep surface of the muscle; it will be learnt in the dissection of the otic ganglion (Section 14). The buccal branch (^), longer and larger than the others, peiforates the external pterygoid, and is directed inwards, beneath the coronoid process to the surface of the buccinator, where it ends in terminal branches. As it perforates the pterygoid muscle filaments are given to the fleshy sub- 96 DISSECTION OF THE PTERYGOID REGION. Stance; and after it has passed through the fibres it furnishes a branch to the temporal muscle. The nerve is directed towards tlie angle of the mouth, supplying the integument, the buccinator muscle, and the lining mucous membrane. It is united freely with the facial nerve, the two forming a plexus. The LARGER PART of the inferior maxillary nerve divides into three trunks — auriculo-temporal, dental, and gustatory. A few of the fibrils of the small (motor) root are applied to it, and are conveyed to certain mus- cles, viz., tensor tympani, circumfiexus palati, pterygoideus, internus, my- lohyoideus, and digastricus. The AURICULO-TEMPORAL NERVE (*) separates from the others near the base of the skull, and has commonly two roots. Its course to the sur- face of the head is directed first backwards beneath the external pterygoid muscle, as far as the inner part of the articulation of the jaw ; and, then, upwards with the temporal artery in front of the ear. The nerve furnishes branches to the surrounding parts, viz., the joint, the ear, and the parotid gland; and it communicates with the i'acial nerve. Its ramifications on the head are described at page 23. In the part now dissected its branches are the following: — a. Branches of the meatus auditorius. Two offsets are given to the meatus from the point of union of the branches of the facial with the auriculo-temporal nerve, and enter that tube between the cartilage and bone. h. Articular branch. The branch to the joint of the jaw arises near the same spot as the preceding, or from the branches to tlie meatus. c. The inferior auricular brarich supplies the external ear below the meatus auditorius: it sends offsets along the internal maxillary artery, which communicates with the sympathetic nerve. d. Parotid branches. Tliese small filaments ramify in the gland. e. Communicating brandies. Two or more branches around the ex- ternal carotid artery communicate wnth the facial and sympathetic nerves. The INFERIOR DENTAL Q) is the largest of the three trunks into which the inferior maxillary nerve divides. In its course to the canal in the lower jaw, the nerve is external to the gustatory, and lies at first beneath the external pterygoid muscle; it is afterwards placed on the internal pterygoid, and on the internal lateral ligament near the dental foramen. After the nerve enters the bone, it is continued forwards beneath the teeth to the foramen in the side of the jaw, and ends at that spot by dividing into an incisor and a labial branch. Only one muscular offset (mylo-hyoid) is supplied by the dental nerve before it enters the bone. Its branches are: — a. The mylo-hyoid branch arises from the trunk of the nerve near the dental foramen, and is continued along a groove on the inner aspect of the ramus of the jaw to the cutaneous surface of the mylo-hyoideus, and to the anterior belly of the digastric muscle. b. The dental branches arise in the bone, and supply the molar and bicuspid teeth. If the bone is soft, the canal containing the nerve and artery may be laid open so as to expose these branches. c. The incisor branch continues the trunk of the nerve onwards to the middle line, and furnishes ofl'sets to the canine and incisor teeth, beneath which it lies. d. The labial branch (mental?) (fig. 9, '^) issues on the face beneath DISSECTION OF THE SUBMAXILLARY RElUON. 97 the depressor of the an^le of tlie mouth. It gives branches to the muscles below the aperture of the moutli, and communicates with the facial nerve; but the greater part of tlie branch is directed upwards beneath the depressor labii inferioris, and is distributed on the inner and outer surfaces of the lower lip. The inferior dental artery^ after entering the lower jaw, has a similar course and distribution to the nerve. Thus it supplies offsets to the bone, dental branches to the molar and bicuspid teeth, and ends anteriorly in an incisor and a labial branch. The incisor branch is continued to the symphysis of the jaw, where it ends in the bone: it lies beneath the canine and incisor teeth, to which it furnishes twigs. The labial branchy issuing by the labial foramen, ramifies in the struc- tures covering the lower jaw, and communicates with the branches of the facial artery. The GUSTATORY or LINGUAL NERVE (^) is the remaining trunk of the inferior maxillary, and is concealed at first, like the others, by the exter- nal pterygoid muscle. It is then inclined inwards with a small artery over the internal pterygoid muscle, and under cover of the side of the jaw to the tongue. The remainder of the nerve will be seen in the dissection of the submaxillary region. In this course under the jaw the nerve does not distribute any branch to the parts around, but the following communicating branch is received by it. The chorda tympani is a branch of the facial nerve, and is distributed to the tongue. P^scaping from the tympanum by the Glaserian fissure, this small branch (*) is applied to the gustatory nerve at an acute angle. At the point of junction some fibrils communicate with the gustatory, but the greater part of the chorda tympani is conducted along tliat nerve to the tongue. The origin of the nerve, and its course across the tympanum to its posi- tion beneath the external pterygoid, are described in Section 14. Section VII. SUBMAXILLARY REGION. The submaxillary region is situate between the lower jaw and the hyoid bone. In it are contained the muscles of the os hyoides and tongue, the vessels and nerves of tlie tongue, and the sublingual and submaxillary glands. Position. In this dissection the position of the neck is the same as for the examination of the anterior triangle. Dissection. If any fatty tissue has been left on the submaxillary gland, or on the mylo-hyoid muscle, when the anterior triangular space was dis- sected, let it be taken away. The submaxillary gland (fig. 16, ") lies below the jaw in the anterior part of the space limited by that bone and the digastric muscle. Its shape is irregular, and the facial artery winds over the surface. It rests on the mylo-hyoideus, and sends a deep process round the posterior or free border 7 98 DISSECTION OF THE SUBMAXILLARY REGION. of that muscle. In front of it is the anterior belly of the digastric ; and behind is the stylo-maxillary ligament separating it from the parotid. Occupying a position somewhat below the side of the jaw, the gland is very near the surface, being covered only by the integuments and pla- tysma, and the deep fascia. In structure the submaxillary resembles the parotid gland (p. 42) ; and its duct — duct of Wharton — issuing from the deep process, extends beneath the mylo-hyoid muscle to the mouth. Dissection. To see the mylo-hyoid muscle, detach the anterior belly of the digastric from the jaw, and dislodge without injury the submaxillary gland from beneath the bone. The MYLO-HYOID MUSCLE (fig. 33, ^) is triangular in shape, with the base at the jaw and the apex at the hyoid bone, and unites along the middle line with its fellow of the opposite side. It arises from the mylo- hyoid ridge on the inner surface of the lower jaw as far back as the last molar tooth ; and is inserted into the middle of the body of the os hyoides, as well as into a central tendinous band between that bone and the jaw. On the cutaneous surface lie the digastric muscle, and the submaxillary gland, the facial artery with the submental offset, and its own branch of nerve and artery. Its fibres are frequently deficient near the jaw, and allow the next muscle to be seen. Only the posterior border is unattached, and round it a piece of the submaxillary gland winds. The parts in con- tact with the deep surface of the muscle will be perceived after the under- mentioned dissection has been made. Action. The lower jaw being fixed the muscle approaches the os hyoides to the jaw, enlarging the pharynx preparatory to swallowing. With the hyoid bone immovable, the mylo-hyoideus can help in de- pressing the jaw, and opening the mouth. Dissection. To bring into view the muscles beneath the mylo-hyoid, and to trace the vessels and nerves to the substance of the tongue (as in figure 23), the student should first divide the facial vessels on the jaw, and remove them with the superficial part of the submaxillary gland; but he should be careful to leave the deep part of the gland which turns be- neath the mylo-hyoideus, because the small submaxillary ganglion is in contact with it. Next he should cut through the small branches of ves- sels and nerve on the surface of the mylo-hyoideus; and detaching that muscle from the jaw and its fellow, should throw it down to the os hyoides, but w^ithout injuring the genio-hyoid muscle beneath it. Afterwards the bone is to be sawn through on the right side of the muscles attached to tiie symphysis, the soft parts covering the lower jaw having been previously cut. The side of the jaw, which will then be loose (for the ramus of the bone has been sawn before), is to be raised to see the parts beneath, and it may be fastened u[) out of the way with a stitch ; but it should not be detached from the mucous membrane of the mouth. The apex of the tongue is to be now pulled well out of the mouth over the upper teeth, and fastened with a stitch to the septum of the nose, whilst the left half of the jaw is to be drawn down forcibly with hooks. The scalpel should be then passed from below upwards between the sawn surfaces of the bone, for the purpose of dividing a strong band of the mucous membrane of the mouth ; and it should be carried onwards along the middle line of the tongue to the tip. By means of a stitch the os hyoides may be fastened down, to make IIYOID AND STYLOID MUSCLES. 99 tight the muscular fibres. All the fat and areolar tissue are to be removed, and in doing this the student is to take care of the Whartonian duct; of the hypoglossal nerve and its brandies, wliich lie on the hyo-glossus mus- cle, and especially of its small offset ascending to the stylo-glossus mus- cle ; also of the gustatory nerve nearer the jaw. Between the gustatory nerve and the deep part of the submaxillary gland the dissector should seek the small submaxillary ganglion (smaller than a pin's head), with its offsets; and should endeavor to separate from the trunk of the gustatory the small chorda tympani nerve, and to define the offset from it to the submaxillary ganglion. At the hinder border of the hyo glossus clean the lingual vessels, the stylo-hyoid ligament, and the glosso-pharyngeal nerve, all passing beneath that muscle ; and at the anterior border find the issuing ranine vessels which, with the gustatory and hypoglossal nerves, are to be traced on the under surface of the tongue to the tip. Parts beneath mylo-hyoideus (fig. 23). The relative position of the objects brought into view by the steps of the previous dissection is now apparent: — Extending from the cornu of the hyoid bone to the side of the tongue is tlie hyo-glossus muscle, whose fibres are crossed superiorly by those of the stylo-glossus. On the hyo-glossus are placed, from below upwards, the hypoglossal nerve, the Whartonian duct, and the gustatory nerve, the latter crossing the duct ; and near the inner border of the mus- cle the two nerves are united by branches. Beneath the same muscle lie, from below upwards, the lingual artery with its vein, the stylo-hyoid ligament, and the glosso-pharyngeal nerve. Above the hyo-glossus is the mucous membrane of the mouth, with the sublingual gland attached to it in front, and some fibres of the superior constrictor muscle covering it behind near the jaw. Between the chin ajjd the os hyoides, along the middle line, is situate the genio-hyoid muscle ; and larger and deeper than it is a fan-shaped muscle, the genio-hyo-glossus. Along the outer side of the last muscle lie the ranine vessels ; and a sublingual branch for the gland of the same name springs from the lingual artery at the inner border of the hyo-glos- sus. On'the under surface of the tongue, near the margin, lies the gus- tatory nerve ; and in the fibres of the genio-hyo-glossus runs the hypo- glossal nerve. The iiYO-GLOSSus MUSCLE (fig. 22, ^) is thin and somewhat square in shape. The muscle arises from the lateral part of the body of the os hyoides (basio-glossus), and from all the great cornu of the same bone (cerato-glossus). The two pieces form a thin sheet, and enter the back part and side of the tongue ; they will be seen afterwards to mingle with fibres of the palato- and stylo-glossus.^ The parts in contact with the surfaces of the hyo-glossus have been already enumerated ; and beneath the muscle also are portions of the genio-hyo-glossus and middle constrictor. Along the anterior border is the genio-hyo-glossus muscle. Action. When the tongue is at rest, the muscle can bring that organ to the floor of the mouth, drawing down the sides and giving a rounded 1 A third part (chondro-glossus) is distinct from the others, and is not dissected ; it ends on the upper surface of the tongue near the root. For further details re- specting the anatomy of this and the otlier lingual muscles, reference is to be made to the dissection of the tongue, Section 15. 100 DISSECTION OF THE SUBMAXILLARY REGION, Fig. 22. form to the dorsum ; but if the tongue is protruded from the mouth, the fibres will retract it into that cavity. If the tongue is fixed against tiie roof of the mouth by other mus- cles, even though the lower jaw is depressed, this muscle with the genio- hyo-glossus will elevate the os hyoides, and allow swallowing to take place. The STYLO-GLOSSUS (fig. 22, ^) is a slender muscle, whose attachments are expressed by its name. Arising from the styloid process near the apex, and from the stylo-maxillary ligament, the muscle is continued for- wards to the side of the tongue. Here it gives fibres to the dorsum, and turning to the under surface, extends to the tip of the tongue. Beneath the jaw this muscle is crossed by the gustatory nerve. Action. Both muscles will raise the back of the tongue against the roof of the mouth, but if the tongue is protruded they will restore it to the cavity. One muscle can direct the point of the tongue towards its own side of the mouth. The GENio-HYOiD MUSCLE (fig. 22, *) arises from the lower of the two lateral tubercles on the inner aspect of the symphysis of the jaw, and is in- serted into the middle of the hyoid ^ bone. A^'J aHyi'^^"'"^ " Covered by the mylo-hyoideus, this \jirwl "'^ muscle rests on the genio-hyo-glossus. The inner border touches the muscle of the opposite side, and the two are often united. Action. As long as the mouth is shut it raises the hyoid bone ; but acting from the os hyoides, and the closers of the mouth being relaxed, it can depress the jaw and open the mouth. The GENIO-HiO-GLOSSUS (fig. 22,^) is the largest muscle of this region ; it has a triangular form, with tiie apex at the jaw, and the base at the middle line of the tongue. It takes origin from the upper tubercle behind the symphysis of the jaw. From this spot the fibres radiate, the posterior passing downwards to their insertion into the body of the hyoid bone, the anterior forwards to the tip of the tongue, and the intermediate to the tongue from root to point. Lying along the middle of the tongue, it is in contact with its fellow. The lower border of the muscle corresponds with the genio-hyoideus, and the upper with the fra3num linguae On its outer side are the ranine ves- sels, and the hyo-glossus muscle ; and the hypoglossal nerve perforates the posterior fibres. Action. By the simultaneous action of all the fibres the tongue is depressed in the floor of the mouth, and hollowed along the middle. But different parts of the muscle are thought to have difterent uses when they Muscles of the TojfauE. 1. Hyo-glossus. 4. Genio-hyoideus. 2. Stylo-glossus. 5. Stylo-pharyngeus. 3. Genio-hyo-glossus. GUSTATORY NERVE. 101 act from the jaw : — Thus the fibres attached to the os hyoides advance and fix that bone before swallowing ; the hinder tongue fibres raise the root of the tongue and protrude the tip, and the anterior then turn down the tip of the tongue over the teeth. When the mouth is open swallowing can be performed if the tongue is fixed against the teeth and roof of the mouth, because this muscle and the hyo-glossus can then raise the hyoid bone. The lingual artery (fig. 11^ f), arises from the external carotid between the superior thyroid and facial branches. At first it is directed inwards above the os hyoides, and then upwards beneath the hyo-glossus to the under part of the tongue (fig. 23) ; it ends at the anterior border of that muscle in the sublingual and ranine branches. Near the hyo-glossus the artery is crossed by the ninth nerve, and by the digastric and stylo-hyoid muscles. Beneath the hyo-glossus, the vessel rests on the middle con- strictor and genio-hyo-glossus muscles, and is below the level of the glosso- pharyngeal nerve. Its branches are these : — a. A small hyoid branch is distributed on the upper border of the os hyoides, supplying the muscles ; it anastomoses with its fellow of the oppo- site side, and with the hyoid branch of the superior thyroid artery of the same side. b. A branch to the dorsum of the tongue arises beneath the hyo-glossus muscle, and ascends to supply the substance of the tongue and the tonsil. The fibres of the hyo-glossus must be divided to see it. c. The sublingaal branch springs from the final division of the artery at the edge of the hyo-glossus, and is directed outwards to the gland of the same name. Some offsets supply the gums and the contiguous muscles, and one continues behind the incisor teeth to join a similar artery from the other side. d. The ranine branch (9) is the terminal part of the lingual artery, and extends forwards along the outer side of the genio-hyo-glossus to the tip of the tongue where it ends. Muscular oflTsets are furnished to the sub- stance of the tongue of the same side. This artery lies along the frienum linguse, but is imbedded in the muscular fibres. The lingual vein commences on both the upper and under surfaces of the tongue. It lies with its companion artery, and ends in the internal jugular vein. The GUSTATORY or LINGUAL NERVE (fig. 23, ^) has been followed in the pterygo-maxillary region to its passage between the ramus of the lower jaw and the internal pterygoid muscle (p. 97). In this dissection the nerve is inclined forwards to the side of the tongue, across the mucous membrane of the mouth and the origin of the superior constrictor muscle, and above the deep part of the submaxillary gland. Lastly, it is directed across the Wliartonian duct, and along the side of the tongue to the apex. Branches are furnished to the surrounding parts, thus : — Two or more offsets connect it with the submaxillary ganglion, near the gland of that name. Farther forwards branches descend on the hyo-glossus to unite in a kind of plexus with twigs of the hypoglossal nerve. Other filaments are supplied to the mucous membrane of the mouth, the gums, and the sublingual gland. Lastly, the branches for the tongue ascend tlirough the muscular sub- stance, and are distributed to the conical and fungiform papilhe. The submaxillary ganglion (fig. 23, ^) resembles the other ganglia 102 DISSECTION OF THE SUBMAXILLARY REGION. connected with the three trunks of the fifth nerve, and communicates with sensory, raotory, and sympatlietic nerves. It is smaller in size than the lenticular ganglion, is sometimes rather red, and is placed above the deep process of the submaxillary gland. Offsets proceed upwards to connect it with other nerves ; and from the lower part arise the branches to the ad- jacent structures. Connection with nerves — roots. Two or three branches, in the form of loops, pass from the ganglion to the gustatory nerve. At the posterior Fig. 23. Muscles : a. Oenio-hyo-glossus. B. Genio-hyoiileus. c. Hyo-glossus. D. Stylo-glos8us. E Mylo-hyoideus, reflected. H. Stylo-hyoideiis. J. Posterior belly of digastricus. Nerves: 1. Gustatory. 2. Submaxillary ganglion. .3. Wharton's duct. 4. Glosso-pharyugeal nerve. 6. Hypo-glossal. 7. Upper laryngeal. The lingual ar- tery ramifies in this region, lying by the side of the hypoglossal nerve : the rauine ofiFset is marked with 9. Deep view of the Submaxillary Kegion (Illustrations of Dissections). part the ganglion is further joined by an offset from the chorda tympani, (of the facial nerve) which lies in contact with the gustatory. And its sympathetic branch comes from the nerves around the facial artery. Branches. From the lower part of the ganglion five or six branches descend to the substance of the submaxillary gland ; and from the anterior part other filaments are furnished to the mucous membrane of the mouth and the Whartonian duct. Chorda tympani. Joining the gustatory above by fibrils (p. 97), it is applied to the back of that nerve till near the tongue, and can be easily separated from it ; but beyond that point it enters amongst the fibres of the gustatory nerve and is conveyed to the tongue. Near the submaxil- lary gland an offset is sent to the submaxillary ganglion. The HYPO-GLOSSAL or NINTH NERVE (fig. 23, ^) in the submaxillary region lies on the hyo-glossus muscle, being concealed by the mylo- hyoideus : but at the inner border of the hyo-glossus it enters the fibres of the genio-hyo-glossus, and is continued along the middle line of the tongue to the tip. Branches. On the hyo-glossus the ninth nerve furnislies branches to the muscles of the submaxillary region, except the mylo-hyoid and the digastric, viz., to the hyo-glossus, stylo-glossus, genio-hyoideus, and genio- hyo-glossus. Further, some offsets communicate with the gustatory nerve on the hyo-glossus. Along the middle of the tongue the nerve sends upwards long filaments UPPER MAXILLARY NERVE. 103 wliich supply the muscular structure, and communicate with the gustatory nerve. The glosso-pharyngeal cranial nerve (fig.23, *), issuing between the two carotid arteries, courses over the stylo-pharyngeus and the middle constrictor of the pharynx, and ends under the hyo-glossus in branches for the tongue. See Dissection of the Toxgue. The duct of the submaxillary gland (fig. 28, ^), Wharton's duct, issues from the deep part of the glandular mass turning round the border of the mylo-hyoid muscle. It is about two inches in length, and is directed up- wards on the hyo-glossus muscle, and beneath the gustatory nerve, to open on the side of the frasnum linguoe in the centre of an eminence : its opening in the mouth will be seen if a bristle be passed along it. The duct has a thin wall, and consists externally of a fibrous layer with much elastic tissue and a few pale muscular fibres, and internally of a mucous lining with flattened epithelium. The dee[3 part of the submaxillary gland extends along the side of the duct, reaching in some instances the sublingual gland. The suhlingual gland {^g. 23, ^) is somewhat of the shape of an almond, and the longest measurement, which is about one inch and a half, is directed backwards. It is situate beneath the anterior part of the tongue, in con- tact with the inner surface of the lower jaw, and close to the symphysis. Separated from the cavity of the mouth by the mucous membrane, the gland is prolonged across the upper border of the genio-hyo-glossus muscle, so as to touch the one of the opposite side. The sublingual is an aggregation of small glandular masses, each being provided with a separate duct (Henle). The ducts (ductus Riviniani) are from ten to eighteen in number. Some of them open beneath the tongue along a crescent-shaped fold of the mucous membrane, and others join the Whartonian duct ; one or more form a larger tube, which either joins that duct 01- opens near it. Section VIII. SUPERIOR MAXILLARY NERVE AND VESSELS. Directions. The student may examine next the right orbit, and the remaining trunk, superior maxillary of the fifth nerve. Supposing the right orbit to be untouched, the student may vary his former examination of the left cavity (p. 50) by dissecting it from the outer side. Dissectio7i. For this purpose divide the margin of the orbit with a saw through the supra-orbital notch, and the roof with a chisel back to the sphenoidal fissure. Cut also with a chisel (from the inside) along the middle fossa of the base of the skull from the sphenoidal fissure in front to the foramen spinosum behind, and outside the line of the foramen ro- tundum and foramen ovale. The side of the skull is next to be sawn ver- tically in front of the petrous part of the temporal bone, so that the incision shall end at the posterior extremity of the cut made in the base. After- wards the outer wall of the orbit is to be sawn horizontally into the spheno- maxillary fissure. The piece of bone forming part of the cranium and 104 DISSECTION OF THE NECK. orbit is now loose, and is to be removed with the temporal muscle. If the part of the roof of the orbit, which is left, should interfere with tiie sight of the contents of the cavity, let it be taken away with a bone-forceps. The description of the orbit (p. 51) will serve in a general way for the right cavity. The superior maxillary division of the fifth nerve, in its course to the face, occupies successively the skull, the spheno-maxillary fossa, and the infra-orbital canal. The beginning of the nerve in the cranium has been already demon- strated (p. 31). Dissection. In the spheno-maxillary fossa the nerve can be partly seen by the dissection already made for the orbit, and its exposure here will be completed by removing the fat, and cutting away some of the wing of the sphenoid bone, so as to leave only an osseous ring round the nerve at its exit from the skull. In the fossa the student seeks the following offsets, the orbital branch entering the cavity of the orbit ; branches to Meckel's ganglion which descend in the fossa ; and a dental branch along the back of the upper jaw. To follow onwards the nerve in the floor of the orbit, the contents of the cavity having been taken away, the bony canal in which it lies must be opened to tlie face. Near the front of the orbit the anterior dental branch is to be traced downwards for some distance in the bone. The infraorbital vessels are prepared with the nerve. The Superior maxillary nerve (fig. 24) commences in the Gasse- rian ganglion (p. 31), and leaves the cranium by the foramen rotundum. The course of the nerve is almost straight to the face, across the spheno- maxillary fossa, and along the orbital plate of the superior maxilla and the infraorbital canal. Issuing from tlie canal by the infraorbital foramen, it is concealed by the elevator of the upper lip, and ends in branches to the eyelid, nose, and upper lip : — a. The orbital hranch (^) arises in the spheno-maxillary fossa, and en- tering the orbit, divides into malar and temporal branches (p. GO). h. The spheno -palatine branches (^) descend from the nerve in the fossa, and supply the nose and the palate; they are connected with Meck- el's ganglion, and will be dissected with it (Section 14). c. A posterior dental branch (^) leaves the nerve near the upper jaw. It enters a canal in the maxilla, and supplies branches to the molar teeth and the lining membrane of the antrum ; it joins the anterior dental branch near the teeth. Before entering the canal it furnishes one or more offsets to the gums and the buccinator muscle. d. The anterior dental branch (*) quits the nerve trunk in the floor of the orbit, and descends to the anterior teeth in a s{)ecial canal in front of the antrum: it is distributed by two branches. One (inner) gives nerves to the incisor and canine teeth, and furnishes one or two fllaments to the lower meatus of the nose; the other (outer) ends by supplying the bicuspid teeth. e. Before the trunk ends in the facial branches, it supplies a small pal- pebral o^^gX to the lower eyelid; this is directed upwards to the lid in a groove in the margin of the orbit. /. Infraorbital or facial branches (^). These are larger than the other offsets of the nerve, and form its terminal ramifications. Some incline inwards to the side of the nose, and the rest descend to the upper lip. Near the orbit they are crossed by branches of the facial nerve (fig. 9, "), UPPER MAXILLARY NERVE, 105 with which they communicate, the whole forming the infraorbital plexus (p. 49). g. The branches for the side of the nose supply the muscular and te^^u- mentary structures. Fig. 24. 2. Trunk of the nerve leaving the Gasserian ganjrlion. 3. Spheno-palatine branches. 4. Temporo-malar branch. 5. Posterior dental nerves. 6. Anterior dental. 7. Facial branches. Diagram of the Upper Maxillary Nerve and its Branches. h. The branches for the upper Up are three or four in number, which divide as they descend, and are distributed chiefly to the surfaces of the lip, though they supply as well the muscles and the labial glands. The infraorbital artery is a branch of the internal maxillary (p. 94). Taking the course of the nerve through the infraorbital canal, the vessel appears in the face beneath the elevator muscle of the upper lip; and it ends in branches, which are distributed, like those of the nerve, to the parts between the eye and mouth. In the face its branches anastomose with the facial and buccal arteries. In the canal in the maxilla the artery furnishes branches to the orbit. Another branch, anterior dental^ runs with the nerve of the same name, anf supplies the incisor and canine teeth : this gives offsets to the antrum of the maxilla, and near the teeth it anastomoses with the posterior dental artery. The vein^ accompanying the artery, communicates in front with the facial vein; and terminates behind in a plexus of veins (alveolar) corre- sponding with the offsets of the internal maxilla artery in the spheno- maxillary fossa. Section IX. DEEP VESSELS AND NERVES OF THE NECK. In this Section are included the deepest styloid muscle, the internal carotid and ascending pharyngeal arteries, and some cranial and sympa- thetic nerves. Position. The position of the part is to remain as before, viz., the neck is to be fixed over a small block. 106 DISSECTION OF THE NECK. Dissection. To see the stylo-pharyngeus muscle, the posterior belly of the digastric, and the stylo-hyoid muscle, should be detached from their origin and thrown down. The trunk of the external carotid artery is to be removed by cutting it through where the hypoglossal nerve crosses it, and by dividing those branches of it that have been already examined; the veins accompanying the arteries are to be taken aw^ay. In cleaning the surface of the stylo-pharyngeus muscle, the glosso-pharyngeal nerve and its branches, and the stylo-hyoid ligament may be prepared. The side of the jaw is to be drawn forwards on the face. The STYLO-PHARYXGEus MUSCLE (levator pharyngis externus) resem- bles the other styloid muscles in its elongated form. The fibres arise from the root of the styloid process on the inner surface, and descend be- tween the superior and middle constrictors to be inserted partly into the pharynx, and partly into the upper border (hinder border, MerkeP) of the thyroid cartilage. Tlie muscle lies below the stylo-glossus, and between the carotid arte- ries ; and the glosso-pharyngeal nerve turns over the low^er part of its flesliy belly. Action. It elevates and draws outwards the part of the pharynx above the hyoid bone, making the tube ready for the reception of the morsel to be swallowed. From its attachment to the thyroid cartilage it will raise the larynx ; and by its position it will control the movement forwards of the air tube. The stylo-hyoid ligament is a fibrous band, which extends from the tip of the styloid process to the small cornu of the os hyoides. Its position is between the stylo-glossus and stylo-pharyngeus muscles, and over the in- ternal carotid artery ; whilst the lower end is placed beneath the hyo- glossus muscle. To the posterior border the middle constrictor muscle is attached below\ It is frequently cartihiginous or osseous in part of, or in all its extent. Occasionally a slij) of fleshy fibres is continued along it. The INTERNAL CAROTID ARTERY Supplies parts within the head, viz., the brain, the eye and orbit, and the nose ; and takes a circuitous course through and along the base of the skull before it terminates in the brain. 'I'he arterial trunk in the cranium, and its offset to the orbit, have been already examined ; but the portion in the neck and the temporal bone re- mains to be dissected. The branches of the carotid to the brain are examined with the encephalon. Dissection. For the display of the cervical part of the artery (fig. 2o) there is now but little dissection required. By detaching the styloid pro- cess at the root, and throwing it with its muscles to the middle line, the internal carotid artery and the jugular vein may be followed upwards to the skull. Only a dense fascia conceals them, but this is to be taken away carefully, so that the branches of the nerves may not be injured. In the fascia, and directed inwards over the artery, seek the glosso- pharyngeal nerve and its branches near the skull, and the small pharyn- geal branch of the vagus lower down ; still lower, the superior laryngeal branch of the vagus, with its external laryngeal offset crossing beneath the carotid. Between the vein and artery, close to the skull, will be found the vagus, hypoglossal, and sympathetic nerves; and crossing backwards, over or under the vein, the spinal accessory nerve. External to the ves- ' Anatomie und Phisiologie des Meuschlichen Stiinm und Sprach Organs, Leip- zig, 1807. Von Dr. Merkel. STYLO-PHARYNGEUS MUSCLE. 107 sels a loop of the first and second cervical nerves over the transverse process of the atlas is to be defined ; and from it branches of communica- tion are to be traced to the large ganglion of the sympathetic beneath the artery, and to the vagus and hypoglossal nerves. Ascending to the cranium, on the inner side of the carotid, the ascending pharyngeal artery will be met with. To open the carotid canal in the temporal bone, and to follow the con- tained artery into the cranium, make a cut along the side of the skull in the following manner : the saw being placed beneath the mastoid process, cut forwards to the foramen spinosum in the wing of the sphenoid bone (to whicii spot the side of the skull has been already taken away), and let the instrument be directed through the stylo-mastoid foramen and the root of the styloid process, but rather external to the jugular foramen and the carotid canal. AVhen the piece of bone has been detached, the carotid canal may be opened with the bone forceps. In cleaning the artery in the canal, large and rather red branches of the superior cervical ganglion of the sympathetic will be found on it ; and in a fresh part two small filaments may be recognized with care — one from Jacobson's nerve, joining the sympathetic at the posterior part of the canal ; the other from the vidian nerve, at the front of the canal. On the piece of bone that has been cut off, the dissector may prepare very readily the tympanum with its membrane and chain of bones, and the chorda tympani nerve. The internal carotid artery (fig. 25, d) springs from the bifurcation of the common carotid trunk. It extends from the upper border of the thy- roid cartilage to the base of the skull ; then through the petrous portion of the temporal bone ; and lastly along the base of the skull to the anterior clinoid process, where it ends in branches for the brain. This \vinding course of the artery may be divided into three parts : one in the neck, an- other in the temporal bone, and a third in the cranium. Cervical part. In the neck the artery ascends almost vertically from its origin to the carotid canal, and is in contact with the pharynx on the inner side. The line of the common carotid artery would mark its posi- tion in the neck. Its depth from tlie surface varies like that of the ex- ternal carotid ; and the digastric muscle may be taken as the index of this difference. Thus, below that muscle, the internal carotid is overlapped by the sterno-mastoid and covered by the common teguments, fascia, and the platysma, and is on the same level as the external carotid, though farther back. But, above that muscle, the vessel is placed deeply beneath the external carotid artery and the parotid gland, and is crossed by the styloid process and the stylo-pharyngeus muscle. Whilst in the neck tlie internal carotid lies on the rectus capitis anticus major muscle, which separates it from the vertebrae. Vein. The internal jugular vein accompanies the artery, being con- tained in a sheath witli it, and placed on the outer side. Small vessels. Below the digastric muscle the occipital artery is directed back over the carotid ; and the offset from it to the sterno-mastoi- deus may run down on the carotid trunk. Above the digastric the poste- rior auricular vessels cross the carotid. Nerves. The pneumogastric is contained in the sheath between the artery and vein, being parallel to them ; and tlie sympathetic, also run- ning longitudinally, lies behind the sheath of the vessels. Crossing the artery superficially, from below up, is the hypoglossal, whicli sends the 108 DISSECTION OF THE NECK. descendens noni along it ; next the small pharyngeal branch of the vagus ; and lastly the glosso-pharyngeal. Dii-ected inwards beneath tlie carotid is the superior laryngeal nerve, furnishing the external laryngeal branch ; together with pharyngeal offsets of the upper ganglion of the sympathetic. Fig. 25. Deep Vesskls and Nerves op the Neck (Illustrations of Dissections). Arteries: a. Subclaviau trunk. b. Common carotid. c. External carotid, cut. d. Internal carotid. /'. Inferior palatine branch of the facial. y. Ascending pharyngeal. Nerves: 1. Glosso-pharyngeal. 2. Spinal accessory. 3. Pneumo-gastric or vagus. 4. Hypoglossil. 5. Pharyngeal branch of the vagus. 6. Upper laryngeal branch of the vagus. 7. External laryngeal branch of tlie last. 8. Thyro-hyoid branch of the liyi)oglossal. 9. Descendens noni of hypoglossal, cut. 10. Phrenic nerve of cervical plexus. 11. Brachial plexus. Recurrent of the vagus, winds round the subclavian artery, a. Close to the skull the cranial nerves of the neck are interposed between the artery and the vein. Around the carotid entwine branches of the sympathetic, and offsets of the glosso-[)iiaryngeal nerve. The cervical part of the artery remains much the same in size to the ASCENDING PHARYNGEAL VESSELS. 109 end, though it is sometimes very tortuous; and it usually does not furnish any branch. Part in the temporal bone. In tlie carotid canal the winding course of the vessel commences. The artery first ascends in front of the inner ear (cochlea and tympanum) ; next it is directed forwards almost horizontally; and lastly it turns upwards into the cranium opposite the foramen lacerum (basis cranii). Branches of the sympathetic nerve surround the carotid in the bone. Whilst in the canal the artery supplies a small branch to the cavity of the typanum. The cranial part of the artery is described with the base of the skull (p. 33). The INTERNAL JUGULAR VEIN is continuous with the lateral sinus of the skull, and extends from the foramen jugulare nearly to the first rib. At the lower part of the neck it joins the subclavian to form the innomi- nate vein (p. 79). As far as the thyroid cartilage the vein accompanies the internal carotid, but below that point it is the companion to the common carotid artery ; and it lies on the outer side of each. Its contiguity to the artery is not equally close throughout, for near the skull there is a small interval be- tween them, containing the cranial nerves; and at the lower part of the neck there is a still larger intervening space, in which the pneumogastric nerve with its cardiac branch is found. The size of the upper part of the vein remains much the same till near the OS hyoides, where it is suddenly increased by the addition of those branches of the head and neck, corresponding with branches of the exter- nal carotid artery, wliich do not join the external jugular vein.^ Its lower dilatation and its valves have been referred to (p. 82). The following branches open into the internal jugular, viz., the facial, lingual, thyroid (superior), occipital, and pharyngeal; and at the lower part of the neck it receives the middle thyroid vein. The ascending pharyngeal artery (fig. 2i)^ g) is a long slender branch of the external carotid, which arises near the commencement of that vessel. Directed upwards on the spinal column between the internal carotid and the pharynx, the artery becomes tortuous near the skull, and enters the pharynx above the upper constrictor to end in the soft palate. In the neck the artery gives some small offsets to the surrounding parts, viz., the muscles on the vertebree, the nerves, and the lymphatic glands. A meningeal branch enters the cranium through the foramen lacerum (basis cranii), and is distributed in the dura mater of the middle fossa of the skull ; this is seldom seen in the cranium, because it is but rarely injected. The palatine branchy which is larger than the preceding, divides in the pharynx into two main pieces, which are directed across the fore part of the palate beneath the mucous membrane, and form arches with like branches of the opposite side ; one of these is near the upper, and the other near the lower edge of the soft palate. ■' The size of the pala- tine artery depends upon that of the inferior palatine branch of the facial artery. ' Sometimes the term internal cephalic is applied to the vein between the skull and the hyoid bone ; and the name internal jugular, to the part below that bone and the junction of its large branches. 2 The Anatomy of the Arteries. By R. Quain, F.R.S., p. 110. 110 DISSECTION OF THE NECK. Pharyngeal branches. Other small arteries ramify in the upper con- strictor, the Eustachian tube, the back of the soft palate, and the tonsil. The vein accompanying the pharyngeal artery receives branches from the cranium, the palate, and the pharynx, and ends in the internal jugular vein. Dissection of the cranial nerves in the neck. By the time tliis stage of the dissection has been arrived at, the condition of the parts will not per- mit the tracing of th.e very minute filaments of the cranial nerves in the loramen jugulare of the skull ; and all the paragraplis marked with an asterisk are therefore to be omitted for the present. Afterwards, if a fresh piece of the skull can be obtained, in which the bone has been softened by acid, and the nerves hardened in spirit, the examination of the branches now passed over may be made. * In the foramen lacerum (fig. 26). Supposing the dissection of the internal carotid to be carried out as is described at page 107, let tlie stu- dent cut across with care the jugular vein near the skull. Let him then remove bit by bit with the bone forceps, or with a scalpel if the part has been softened, the ring of bone which bounds externally the jugular fora- men, proceeding as far forwards as the osseous crest between that foramen and the carotid canal. Between the bone and the coat of the jugular vein, the small auricjilar branch of the pneumogastric nerve is to be found; it is directed backwards to an aperture near the styloid process. * Trace, then, the spinal accessory and pneumogastric nerves through the aperture, by opening the fibrous slieath around them. Two parts, large and small, of the spinal accessory nerve should be defined ; the latter is to be shown joining a ganglion on the vagus, and applying itself to the trunk of that nerve. A communication between the two parts of the spinal accessory is to be found. On the pneumogastric is a small well- marked ganglion, from which the auricular branch before referred to takes origin ; and from the ganglion filaments are to be sought passing to the smaller portion of the spinal accessory nerve, and to the ascenaing branch of the upper cervical ganglion of the sympathetic. * Next follow the glosso-pharyngeal nerve through the fore part of the foramen, and take away any bone that overhangs it. This nerve presents two ganglia as it passes from the skull (fig. 26): one (jugular), which is scarcely to be perceived, near the upper part of the tube of membrane containing it; the other, much larger (petrous), is situate at the lower border of the petrous portion of the temporal bone. From the lower one, seek the small nerve of Jacobson, which enters an aperture in the crest of bone between the jugular foramen and the carotid canal ; and another filament of communication with the ganglion of the sympathetic. Some- times the dissector will be able to find a filament from the lower ganglion to join the auricular branch of the pneumogastric ; and anotlier to end in the upper ganglion of the jjueumogastric nerve. Below the foramen of exit from the skull the cranial nerves have been greatly denuded by the dissection of the internal carotid (fig. 25) ; but the intercommunications of the vagus, hypoglossal, sympathetic, and first two spinal nerves near the skull, are to be traced out more completely. The larger part of the spjnal accessory has been sufficiently laid bare already ; but its small piece is to be traced to the vagus, close to the skull, and onwards by the side of that trunk. The chief part of the glosso-pharyngeal has been also dissected ; but the offsets on the carotid, and others to join the pharyngeal branch of the vagus and the pharyngeal plexus are to be disphiyed. GLOSSO-PHARYNGEAL NERVE. Ill On the pneiimogastric trunk the student should define an enlargement close to the skull (ganglion of the trunk) to which the hypoglossal nerve is intimately united. From the ganglion proceed two branches (pharyn- geal and laryngeal), which are to be traced to the parts indicated by their names, especially the first which enters the pharyngeal plexus. The task of disentangling the ramifications of the branch of the vagus, and those of the glosso-pharyngeal and sympathetic in the plexus, is by no means easy, in consequence of the dense tissue in which they are contained. Two or more cardiac offsets of the vagus, one at the upper and another at the lower part of the neck, may be recognized readily. Lastly the dissector may prepare more fully the recurrent branch coursing up beneatli the lower part of the common carotid : by removing the fat around it, offsets will be seen entering the chest and the windpipe. Only the first, or the deep part of the hypoglossal nerve remains to be made ready for learning ; its communications with the vagus, sympathetic, and the spinal nerves are to be demonstrated. A dissection for the sympathetic will be given further on (p. 110); but its large ganglion near the skull (upper cervical) should be defined, and the small branches from it to the pharyngeal plexus should be pursued beneath the carotid artery. The three cranial nerves^ glosso-pharyngeal, pneumogastric, and spinal accessory, which constitute the eighth nerve of Willis, leave the cranium by the foramen jugulare (p. 32). Outside the skull the nerves take dif- ferent directions according to their destination ; thus the glosso-pharyngeal is inclined inwards to the tongue and pharynx ; the spinal accessory back- wards to the sterno-mastoid and trapezius muscles ; and the pneumogastric nerve descends to the viscera of the thorax and abdomen. The GLOSSO-PHARYNGEAL NERVE (fig. 26, ') is the Smallest of the three trunks. In the jugular foramen it is placed somewhat in front of the other two, and lies in a groove in the lower border of the petrous part of the tem- poral bone. In the aperture of exit the nerve is marked by two ganglionic swellings, the upper one being the jugular, and the lower the petrous ganglion. * Ganglia. Tha jugular ganglion, *, (ganglion superius) is very small, and is situate at the upper part of the osseous groove containing the nerve. It is placed on the outer surface of the glosso-pharyngeal trunk, and in- cludes only some fibrils of the nerve. The petrosal ganglion, ^, (gang, inferius) is much larger than the preceding, and incloses all the fibrils of the nerve. Ovalish in form, it is placed in a hollow in the lower border of the temporal bone ; and from it spring the branches that unite the glosso- pharyngeal with other nerves-. After the nerve has quitted the foramen it comes forwards between the jugular vein and the carotid artery (fig. 25, ^), and crossing inwards over the artery, reaches the lower border of the stylo-pharyngeus muscle. At this spot the nerve becomes almost transverse in direction in its course to the pharynx; it crosses over the stylo-pharyngeus, and forms an arch across the side of the neck above the superior laryngeal nerve. Finally it passes beneath the hyo-glossus muscle, and ends in branches to the pharynx, the tonsil, and the tongue. The branches of the glosso-pharyngeal may be classed into those con- necting it with other nerves at the base of the skull, and those distributed in the neck. * Connecting branches arise chiefly from the petrosal ganglion ; and in this set is the tympanic nerve. 112 DISSECTION OF THE NECK. * K filament ascends from the sympathetic nerve in the neck to join the petrosal ganglion. Sometimes there is an offset from the ganglion to the auricular branch of the vagus, as well as to the upper ganglion of this nerve. * The tympanic branch (fig. 26, *) (nerve of Jaoobson) enters the aperture in the ridge of bone between the jugular and the carotid foramen, and ascends by a special canal to the inner wall of the tympanum, where it ends in branches : its distribution is given with the tympanum of the ear. a. Banches for Distribution. In the neck the branches are furnished chiefly to the pharynx and the tongue. b. Carotid branches surround the internal artery of that name, and communicate with the pharyngeal branch of the vagus, and the sympa- thetic nerve. c. Some muscular branches enter the stylo-pharyngeus, whilst the nerve is in contact with it. d. Branches to the pharynx form the pharyngeal plexus by uniting with nerves from the sympathetic and vagus. e. The tonsillitic branches supply the tonsil and the arches of the soft palate. On the former they end in a kind of plexus — circulus tonsillaris. /. Lingual branches. The terminal branches of the nerve supply the root and posterior part of the tongue, as well as the lateral surface. The distribution of these is described with the tongue (Section 15). Tiie PNEUMOGASTRic NERVE (fig. 2G, ^) (vagus nerve) is the largest of the cranial nerves in the neck, and escapes through the jugular foramen Fig. 26. Glosso-pharyngeul trunk. Vagus. Spinal accessory. Jugular ganglion. Petrosal ganglion. Jacobson's nerve. Auricular branch. Kooc ganglion of vagus. Trunk ganglion of vagus. Branch joining the petrosal and upper ganglion of the vagus. Small part of spinal accessory. Chief part of spinal accessory. Pharyngeal branch of vagus. Superior laryngeal branch of vagus. Diagram of the Eighth Nerve in the same sheath of dura mater as tlie spinal accessory. In tlie aperture of exit it has a distinct ganglion (gang, of the root), to which the smaller part of the spinal accessory nerve is connected. PNEUMOGASTRIC NERVE. 113 When the nerve has left the foramen, it receives the small part of the spinal accessory, and swells into a ganglion nearly an inch long (gang, of the trunk). Here the nerve lies between the internal carotid artery and jugular vein, and communicates with several nerves. To reach the thorax, the vagus descends almost vertically (fig. 25, ') between the internal jugu- lar vein and the internal and common carotid arteries; and enters that cavity, on the right side, by crossing over the subclavian artery, but beneath the innominate vein. * Ganglia. The ganglion of the root (gang, superius), (fig. 26, ^) is of a grayish color, and in texture is like the ganglion on the large root of the fifth nerve. Small branches in the foramen jugulare come from this gan- glion. The ganglion of the trunk (gang, inferius), (^) is cylindrical in form, is reddish in color, and is nearly an inch in length; it communicates with the hypoglossal, spinal, and sympathetic nerves. All the intrinsic fibres of the trunk of the nerve are surrounded by the ganglionic substance, but those derived from the spinal accessory nerve (") pass over the gan- glion without being inclosed in it. The branches of the pneumogastric nerve may be arranged into those uniting it with other nerves, and those distributed to parts around. * Connecting branches (fig. 26) arise from the ganglion of the root and the ganglion of the trunk of the vagus. * From the ganglion of the root. The auricular branch (J) is the chief offset, and crosses the jugular fossa to enter an aperture near the root of the styloid process ; it traverses the substance of the temporal bone, and reaches the outer ear, on which it is distributed. Its farther course will be described with the anatomy of the ear. * One or two short filaments unite this ganglion with the spinal acces- sory nerve ; and a branch of the sympathetic nerve in the neck enters it. Occasionally there is an offset (^") to join the lower (petrosal) ganglion of the glosso-pharyngeal nerve. From the ganglion of the trunk. Communicating filaments connect it with the hypoglossal nerve. Other branches pass between it and the upper ganglion of the sympathetic, and between it and the loop of the first two cervical nerves. Branches for Distribution (fig. 25). The cervical branches arise from the inner side of the nerve, and are directed inwards, to supply the pharynx, the larynx, and the heart. a. Tlie pharyngeal branch (fig. 26, ^') is an offset from the upper part of the ganglion of the trunk, and terminates in the pharynx. The nerve is directed inwards over the internal carotid artery (fig. 25, *), and joins the branches of the glosso-pharyngeal nerve on that vessel. Finally it courses to the side of the middle constrictor muscle, and communicates with branches of the glosso-pharyngeal, superior laryngeal, and sympa- thetic nerves, to form the pharyngeal plexus. From the plexus branches are furnished to the constrictors and palato-glossus and pharyngeus, and to the pharyngeal mucous membrane between the tongue and the hyoid bone. b. The superior laryngeal nerve (fig. 26,^*) is much larger than the preceding branch, and comes from the middle of the ganglion of the trunk. From this point it inclines obliquely inwards beneath tlie internal carotid artery (fig. 25, ^), and reaches the larynx opposite the interval between the hyoid bone and the thyroid cartilage. Tlie nerve then perforates the thyro-hyoid membrane, and is distributed to the mucous lining of the 8 114 DISSECTION OF THE NECK. larynx. (See *' Larynx.") In the neck it furnishes branches to the thyroid body, and the following off'set to one laryngeal muscle and the pharynx : — The external laryngeal branch (fig. 25, ') arises beneath the internal carotid artery, and runs below the superior laryngeal nerve to the side of the larynx. Here it gives offsets to the pharyngeal plexus, and it is con- tinued beneath the sterno-thyroideus to the crico-thyroid muscle and the inferior constrictor. Near its origin this branch communicates with the superficial cardiac branch of the sympathetic nerve. c. Cardiac branches. Some small cardiac nerves spring from the pneumo-gastric at the upper part of the neck, and join cardiac branches of the sympathetic. At the lower part of the neck, on each side, there is a single cardiac nerve : the right one enters the chest and joins the deep nerves to the heart from the sympathetic ; and the left nerve terminates in the superficial cardiac plexus of the thorax. d. The inferior laryngeal or recurrent nerve (fig. 25) leaves the pneumo- gastric trunk on the right side opposite the subclavian artery, and winding round that vessel, takes an upward course in the neck to the larynx, ascending beneath the common carotid and inferior thyroid arteries, and between the trachea and the oesophagus. At the larynx it enters beneath the ala of the thyroid cartilage, where it will be afterwards traced. The following branches arise from it ; — Some cardiac branches leave the nerve as it turns round the subclavian artery ; these enter the thorax, and join the cardiac nerves of the sym- pathetic. Muscular branches spring from it whilst it lies between the trachea and the esophagus, and are distributed to both those tubes. Near the larynx some filaments are furnished to the inferior constrictor muscle. On the left side the recurrent nerve arises in the thorax, opposite the arch of the aorta, but lies between the trachea and oesophagus in the neck, as on the right side. The SPINAL ACCESSORY NERVE (fig. 26, ^^) courscs through the foramen jugulare with the pneumo-gastric, but is not marked by any ganglion. The nerve is constructed of two parts, viz., accessory to the vagus, and spinal, which have a different origin and distribution. (Origin of the cranial nerves.) The part accessory to the vagus (") is the smaller of the two, and finally blends with the pneumo-gastric beyond the skull. In the foramen of exit it lies close to the vagus, and joins the upper ganglion of tliat nerve by one or two filaments. Below the foramen it is continued over the lower ganglion of the nerve, and blends with the trunk beyond the ganglion. It gives offsets to join the pharyngeal and upper laryngeal branches of tlie pneumo-gastric, and according to Bendz, to many other branches of that nerve. The spinal part (fig. 2G, ^^) is much larger, is round and cord-like, and is connected with tlie smaller piece whilst it is passing through the fora- men jugulare. Beyond the foramen the nerve (fig. 25, ^) takes a back- ward course through the sterno-mastoid muscle, and across the side of tlie neck to end in the trapezius muscle : at first it is concealed by the jugular vein, but it then passes either over or under that vessel. The connections of the nerve beyond the sterno-mastoideus have been already examined (p. 66). SUB-OCCIPITAL NERVE. 115 The nerve furnishes muscular offsets to the sterno-mastoideus and the trapezius. The HYPOGLOSSAL NERVE (ninth of Willis), issuing from the cranium by the anterior condyloid foramen, lies deeply between the internal carotid artery and the jugular vein (fig. 25, *). It next comes forwards between the vein and artery, turning round the outer side of the vagus to which it is united. The nerve now descends in the neck, and becomes superficial below" the digastric muscle in the anterior triangular space ; from this spot it is directed inwards to the tongue and its muscles. * Connecting branches. Near the skull the hypo-glossal is united by branches with the vagus nerve, the two being almost inseparably joined. * Rather lower down the nerve is connected by offsets with the sympa- thetic, and with the loop of the first two spinal nerves. The branches for distribution have been met with in the foregoing dis- sections. Thus in the neck it supplies, in union with the spinal nerves, the depressors of the hyoid bone. In the submaxillary region it furnishes branches to one elevator (genio-hyoid) of the os hyoides ; to the extrinsic muscles of the tongue except the palato and pharyngeo-glossus ; and to all the intrinsic of the tongue. Dissection. The small rectus capitis lateralis muscle, between the transversa process of the atlas and the base of the skull, is now to be cleaned and learnt. At its inner border the anterior branch of the first cervical nerve, which forms part of a loop on the atlas, is to be found. The RECTUS CAPITIS LATERALIS (fig. 25) is Small and thin, and repre- sents an intertransverse muscle. It arises from the anterior transverse process, and the tip of the united transverse processes of the atlas ; and is inserted into the jugular eminence of the occipital bone. On the anterior surface rests the jugular vein ; and in contact with the posterior is the vertebral artery. To the inner side lies the anterior pri- mary branch of the first cervical nerve. Action. It assists the muscles attached to the mastoid process in in- clining the head laterally. Dissection. For the purpose of tracing backwards the anterior branch of the first cervical nerve divide the rectus lateralis muscle, and observe the offset to it ; then cut off the end of the lateral mass of the atlas, and remove the vertebral artery, so as to bring into view the nerve as it lies on the first vertebra. The anterior primary branch of the first or sub-occipital nerve is slen- der in size, and arises from the common trunk on the neural arch of the atlas. From that origin it is directed forwards on the arch, beneath the vertebral artery, to the inner side of the rectus lateralis : here it bends down in front of the lateral mass of the bone, and forms a loop by uniting with the second cervical nerve. As the nerve passes forwards it supplies the rectus lateralis muscle, and branches connect the loop with the vagus, hypoglossal, and sympathetic nerves. Sympathetic Nerve. In the neck the sympathetic nerve consists, on each side, of a gangliated cord, which lies close to the vertebral column, and is continued into the thorax. On this part of the nerve are three ganglia : — One near the skull, another on the neck of the first rib, and a third somewhere between the two ; these are named respectively superior, inferior, and middle ganglion. From the ganglia proceed connecting branches with the spinal and most of the cervical cranial nerves; and branches for distribution to viscera and bloodvessels. 116 DISSECTION OF THE NECK. Besides the ganglia above mentioned, there are other ganglia in the head and neck in connection with tlie three trunks of the fifth nerve. Dissection. To display the brandies of the sympathetic nerve requires greater care than is necessary in tracing the white fibred nerves, for they are softer, more easily torn, and generally of smaller size. In the neck the ganglia and their branches have been partly prepared, and only the following additional dissection will be required to bring them into view : — The jugular vein having been cut through, the upper ganglion will be seen by raising the carotid artery, and the trunks of the vagus and hypo- glossal nerves, and by cutting through the branches that unite these two to the loop of the first and second spinal nerves. The several branches of the ganglion are to be traced upwards on the carotid artery, inwards to the pharynx, down along tlie neck, and outwards to other nerves. The dissector has already seen the middle ganglion on or near the infe- rior thyroid artery, and its branches to spinal nerves, and along the neck, are now to be traced. To obtain a view of the inferior ganglion the greater part of the first rib is to be taken away, and the subclavian artery is to be cut through, inside the scalenus, and drawn aside, without however destroying the fine nerves that pass over it. The clavicle is supposed not to be in position. The ganglion is placed on the neck of the first rib ; its branches are large, and are easily followed outwards to the vertebral artery and the spinal nerves, and downwards to the thorax. The SUPERIOR CERVICAL GANGLION is the largest of the three, and is of a reddish -gray color. Of a fusiform shape, it is as long as the second and third cervical vertebrae, and is placed on the rectus capitis anticus major muscle, beneath the internal carotid artery and the contiguous cra- nial nerves. Branches connect tlie ganglion with other nerves ; and some are distributed to the bloodvessels, the pharynx, and the heart. * Connecting branches unite the sympathetic with both the spinal and the cranial nerves. * With the sj)inal nerves. The four highest spinal nerves have branches of communication with the upper ganglion of the sympathetic ; but the offset to the fourth nerve may come from the cord connecting the upper to the next ganglion. * With the cranial nerves. Near the skull the trunks of the vagus (its lower ganglion) and hypoglossal nerves are joined by branches of the sympathetic. In the foramen jugulare also, both the petrosal ganglion of the glosso-pharyngeal and the ganglion of the root of the vagus receive small filaments, one to each, from an ascending offset of the ganglion. Communications are formed witli several other cranial nerves by means of an offset from the ganglion into the carotid canal (p. 33). Branches for Distribution. This set of branches is more numerous than the preceding, and the nerves are larger in size. Branches for bloodvessels (nervi molles). These nerves surround the external carotid artery, and ramify on its branches so as to form plexuses on the arteries witli tlie same names as the vessels : some small ganglia are occasionally found on these ramifying nerves. By means of the plexus on the facial artery the submaxillary ganglion communicates with the sym- pathetic ; and through the plexus on the internal maxillary artery the otic ganglion obtains a similar communication. Another offset from the upper part of the ganglion accompanies the internal carotid artery and its branches. Near the skull it divides into CERVICAL GANGLIA OF SYMPATHETIC. 117 two pieces, which enter the canal for the carotid, one on each side of that vessel : and are continued to the eyeball and tlie pia mater of the brain, forming secondary plexuses on the ophthalmic and cerebral arteries. In the carotid canal communications are formed with the tympanic nerve (p. Ill) and with the spheno-palatine ganglion (p. 141) ; with the former near the lower, and with the latter near the upper opening of the canal. The communications and plexuses which these nerves form in their course to the base of the brain are described at p. 33. The pharyngeal nerves pass inwards to the side of the pharynx, where they join with other branches of the cranial nerves in the pharyngeal plexus (p. 113). Cardiac nerves enter the thorax to join in the plexuses of the heart. There are tliree cardiac nerves on each side, viz., superior, middle, and inferior, each taking its name from the ganglion of which it is an offset. The superior cardiac nerve (superficial) of the right side courses behind the sheath of the carotid vessels, and enters the thorax beneath the sub- clavian artery. In the neck the nerve is connected with the cardiac branch of the vagus, with the external laryngeal, and with the recurrent nerv^e. In some bodies it ends by joining one of the other cardiac nerves. The MIDDLE CERVICAL GANGLION (gang, tliyroidcum) is of small size, and is situate opposite the fifth cervical vertebra, usually on or near the inferior thyroid artery. It has a roundish shape, and lies beneath the great vessels. Its branches are the following : — * Connecting branches with the spinal nerves sink between the borders of the longus colli and anterior scalenus, to join the fifth and sixth cervi- cal nerves. Branches for Distribution. These consist of nerves to the thyroid body, together with the middle cardiac nerve. The thyroid branches ramify around the inferior thyroid artery, and end in the thyroid body ; they join the external and recurrent laryngeal nerves. The middle or great cardiac nerve descends to the thorax across the subclavian artery ; its termination in the cardiac plexus will be learnt in the chest. In the neck it communicates with the upper cardiac and re- current laryngeal nerves. The INFERIOR CERVICAL GANGLION is of large size but irregular in shape, and occupies the interval between the first rib and the lateral mass of the last cervical vertebra, its position being internal to the superior intercostal artery. Oftentimes it extends in front of the neck of the rib, and joins the first swelling of the knotted cord in the thorax. Its branches are similar to those of the other two ganglia. One or two branches surround the trunk of the subclavian artery, and supply filaments to that bloodvessel. * Connecting branches join the last two cervical nerves. Other nerves accompany the vertebral artery, forming a plexus — vertebral, around it, and communicate with the spinal nerves as high as the fourth. Only one branch for distribution, the inferior cardiac nerve, issues from the lower ganglion. It lies beneath the subclavian artery, joining in that position the recurrent laryngeal nerve, and enters the thorax to terminate in the deep cardiac plexus behind the arch of the aorta. Directions. The student now proceeds to dissect the left side of the neck, but the remains of the right half should be carefully preserved during the time occupied in the examination of the left half. 118 DISSECTION OF THE NECK. Section X. DISSECTION OF THE LEFT SIDE OF THE NECK. Directions. In the dissection of the left half of the neck, the differences observable between it and the right side are specially to be studied. When the description of the right side will suffice, reference will be made to it. After the neck has been made tense over a narrow block, the anterior part of it is to be prepared as on the opposite side. The description of the right side (p. 67 to 73) is to be used for the anterior triangular space, the sterno-mastoideus, and the depressor muscles of the hyoid bone. Next the scaleni muscles and the subclavian vessels are to be learnt. The dissection and description of the muscles on the right side (p. 73 to 75), will serve for those on the left, except that the student will meet on the left side with the thoracic duct. The thoracic duct is contiguous to the part of the subclavian artery in- side the scalenus muscle. If it is uninjected it looks like a vein, rather smaller than a crow-quill; and it will be found by separating the jugular vein from the carotid artery, about half an inch above the clavicle, cours- ing from beneath the artery to end in the subclavian vein. On this side the clavicle may remain articulated, in order that the joint may be learnt. The LEFT SUBCLAVIAN ARTERY ariscs from the arch of the aorta, in- stead of from an innominate trunk, and ascends thence over the Urst rib in its course to the upper limb. With this difference on the two sides in the origin of the subclavian — the one vessel beginning opposite the sterno- clavicular articulation, the other in the thorax — it is evident that the length and connections of the part of the artery on the inner side of the scalenus must vary much on opposite sides. First part. The part of the artery internal to the anterior scalenus is much longer on the left than tlie right side, and is almost vertical in direc- tion, instead of being horizontal like its fellow. After leaving the chest it is deeply placed in the neck, near the spine and the oesophagus, and does not rise usually so high above the first rib as the right subclavian. Between the artery and the surface are structures like those on the right side, viz., the common teguments with the platysma and deep fascia, and the sterno-mastoid, hyoid, and thyroid muscles. Behind the vessel is the longus colli muscle. To the inner side are the oesophagus and the thoracic duct; and the pleura is in contact with the outer and anterior parts. Its connections lower in the chest are described in the dissection of the thorax. Veins. The internal jugular vein is superficial to the artery and paral- lel to it. Nerves. The pneumo-gastric nerve lies parallel to the vessel instead of across it as on the right side; and the phrenic nerve crosses over it close to the scalenus. Accomi)aiiying the artery are the cardiac branches of the sympathetic, which course along its inner side to the chest; and beneath it is the inferior cervical ganglion. The second and third parts of the artery, viz., beneath and beyond ENDING OF THORACIC DUCT. 119 the scalenus, are nearly the same as on the right side (p. 76); but the student must note for himself the variations that may exist in the connec- tions. The branches of this artery resemble so closely those of the right trunk, that one description will serve for both (p. 76 to 78). It may be re- marked, that the superior intercostal of the left side is usually internal to, instead of beneath the scalenus as on the right side; in other words, this branch arises sooner. Tlie thoracic duct (fig. 27, ^) conveys the chyle and lymph of the greater part of the body into the venous circulation. Escaping from the thorax on the oesophagus, the duct ascends in the neck as high as the seventh or sixth cervical vertebra. At the spot mentioned it issues from beneath the carotid trunk, and arches outwards above or over the subcla- vian artery, and in front of the scalenus muscle and the phrenic nerve, to open into the subclavian close to the union with the internal jugular vein. Double valves, like those of the veins, are present in the interior of the tube ; and a pair guards the opening into the posterior part of the vein, to prevent the passage of the blood into it. Frequently the upper part of tlie duct is divided; and there maybe separate openings into the large vein, corresponding with those divisions. Fig. 27. Diagram of the Ending of the Ltmph Duct and the Thoracic Duct in the Veins. 1. Upper veua cava. 8. Thoracic duct. 2. Right, and 3, left innominate vein. 9. A lymphatic vessel joining the right lym- 4. Left, and 5, right internal jugular. phatic duct, as this is about to end in 6. Left, and 7, right subclavian vein. the subclavian vein. Large lymphatic vessels from the left side of the head and neck, and from the left upper limb, open into the upper part of the duct, and some- times separately into the vein Q^). Structure, This tube is formed of three coats like the bloodvessels, viz., inner, middle, and outer. The inner is an elastic layer of longitudi- nal fibres covered by flattened epitlielium; the middle is muscuhir and elastic with transverse fibres; and the outer is constructed chiefly of flbrous tissues arranged longitudinally and obliquely. Examine next the brachial and cervical plexuses, using the description of the right side (p. 79 to 81). 120 DISSECTION OF THE NECK. Common carotids. On opposite sides tliese vessels have differences like those between tlie right and left subclavian arteries; for the left ves- sel arises from the arcli of the aorta, and is therefore deep in the chest, and longer than the right. The description of the artery between its origin and the top of the sternum will be included in the dissection of the thorax. Beyond the sterno-clavicular articulation the vessels, on both sides, so nearly resemble one another that the same description may serve for the two (p. 81). On the left side, however, the jugular vein and the pneumo- gastric nerve are much nearer to the carotid than on the right side, and are placed over the artery in the lower third of the neck.* Parts in the upper aperture of the thorax. The relative po- sition of the several parts entering or leaving the thorax by the upper opening may be now observed. In the middle line lie the remains of the thymus gland, and the trachea and oesophagus. In front of the trachea are the lower ends of the sterno- hyoid and sterno-thyroid muscles with layers of the cervical fascia, and the inferior thyroid veins ; and behind the gullet and windpipe is the longus colli muscle. Between the two tubes is the recurrent nerve on the left side. On each side the bag of the pleura and the apex of the lung project into the neck ; and in the interval between the pleura and the trachea and oesophagus, are placed the vessels and nerves passing between the thorax and the neck. Most anteriorly on both sides lie the innominate vein, the phrenic nerve, and the internal mammary artery ; but the vessels and nerves next met with are different on the two sides. On the right side come the innominate artery, with the vagus, the cardiac nerves, and the right lymphatic duct ; but on the left side are tlie left vagus, the left com- mon carotid artery, the thoracic duct, and the left subclavian artery with the cardiac nerves. Lastly, altogether behind on each side are part of the first intercostal nerve, the cord of the sympathetic, and the superior inter- costal artery. The thyroid body is a soft reddish mass, which is situate opposite the upper part of the trachea. It consists of two lobes, one on each side, which are united by a narrow piece across the front of the windpipe. The connecting piece, about half an inch in depth, is named the isthmus, and is placed opposite the second and third rings of the air tube. Each lobe is somewhat conical in shape, with the smaller end upwards, and is about two inches in length. It is interposed between the windpipe and the sheath of the common carotid artery, and is covered by the sterno- thyroid, sterno-hyoid, and omo-hyoid muscles. The extent of the lobe varies ; but usually it reaches as high as the middle of the thyroid cartilage, and as low as the sixth ring of the tracliea. From the upper part of the thyroid body, and most commonly from the left lobe, a conical piece — pyramid, ascends towards the hyoid bone, to which it is connected by a fibrous band. Sometimes this part is attached to the OS hyoides by a slip of muscle, the levator glandulce thyroidece of Scemmering. This body is of a brownish red or purple hue, is granular in texture, and weighs from one to two ounces. Its size is larger in the woman than ' Occasionally these differences will be reversed — the vein and nerve being over the artery on the right side, and away from it on the left. THYROID BODY. 121 ill the man. On cutting into the gland a viscid yellowish fluid escapes. It has not any excretory tube or duct. Structure. The thyroid body is not provided with a distinct capsule ; but it is surrounded by areolar and fine elastic tissues, which project into the substance and divide it into masses. The substance of the gland consists of spherical or elongated vesicles, which vary in size, some being as large as the head of a small pin, and others only ^|o^^^ ^^ ^^^ inch. These vesicles are simple sacs, distinct from one another, and contain a yellowish fluid with corpuscles. The wall of the vesicles consists of a thin proper membrane with a nucleated epithelial lining. Fine vessels and areolar tissue unite together the vesicles into small irregular masses or lobules of the size of the little finger nail. The arteries of the thyroid body are two on each side — superior and inferior thyroid. The branches of the external carotids (superior thyroid) ramify chiefly on the anterior aspect ; w^hile those from the subclavians (inferior thyroid) pierce the under surface of the body. A very free com- munication is established between all the vessels ; and in the substance of the thyroid body the arteries form a capillary network around the vesicles. Occasionally there is a third thyroid branch {art. thyroid, ima) which arises from the innominate artery into the thorax, and ascending in front of the trachea assists in supplying the thyroid body. The veins are large and numerous ; they are superior, middle, and infe- rior thyroid on each side. The first two enter the internal jugular vein (p. 82). The inferior thyroid vein issues from the lower part of the thy- roid body, and descends on the trachea — the two forming a plexuse on that tube beneath the sterno-thyroid muscles ; it enters finally the innomi- nate vein of its own side. The TRACHEA, or air tube, is continued from the larynx to the thorax, and ends by dividing into two tubes (bronchi) one for each lung. It occu- pies the middle line of the body, and extends commonly from the fifth cervical to the fourth dorsal vertebra, measuring about four inches and a half in length, and nearly one in breadth. The front of the trachea is rounded in consequence of the existence of firm cartilaginous bands in the anterior wall, but at the posterior aspect the cartilages are absent, and the tube is flat and muscular. The cervical part of the trachea is very movable, and has the following relative position to the surrounding parts. Covering it in front are the small muscles reaching from the sternum to the hyoid bone, with the deep cervical fascia : beneath those muscles is the inferior thyroid plexus of veins ; and near the larynx is the isthmus of the thyroid body. Behind the tube is the oesophagus, with the recurrent nerves. On each side are the common carotid artery and the thyroid body. The structure of the trachea is described in Section XYII. The (ESOPHAGUS, or gullet, reaches from the pharynx to the stomach. It commences, like the trachea, opposite the fifth cervical vertebra, and^ ends opposite the tenth dorsal vertebra. The tube reaches through part of the neck, and through the whole of the thorax ; and occupies the middle line of the body. In length it measures about nine inches. In the neck its position is behind the trachea till near the thorax, where it projects to the left side of tlie air tube, and touches the thyroid body and the thoracic duct. Behind the oesophagus is the longus colli muscle. On each side is the common carotid artery, the proximity of the left being greatest because of the projection of the oesophagus towards the same side. 122 DISSECTION OF THE PHARYNX. The structure of the oesophagus will be examined in the dissection of the thorax. Directions. The dissector may learn next the digastric and stylo-hyoid muscles, Avith the hypoglossal nerve (p. 82). Afterwards he may take the trunk of the external carotid, with the following branches — superior thyroid, facial, occipital, posterior auricular, and superficial temporal (p. 83 to 87). The dissector is not to examine now the pterygo-maxillary or sub- maxillary regions on the left side, because such a proceeding would inter- fere with the subsequent dissections. Before learning the pharynx he should lay bare, on this side, the middle and inferior ganglia of the sym- pathetic with their branches. Dissection. For tlie display of the two low^er ganglia of the sympathetic and their branches, it will be necessary to take away the great bloodvessels by cutting them across at the lower part of the neck, and near the digastric muscle. In removing the vessels, care must be taken of the sympathetic beneath them. The middle ganglion must be sought in the fat and areolar tissue near the inferior thyroid artery ; and the inferior one will be seen on the neck of the first rib, after the subclavian artery has been divided. The upper cardiac nerve may be found descending beneath tlie carotid sheath. The upper end of the sternum witli its attached clavicle is to be taken away next, by cutting through the middle of the first rib ; and the piece of bone is to be put aside for the subsequent examination of the sterno- clavicular articulation. The middle and inferior cervical ganglia of the sympathetic nerve are so similar to the corresponding ganglia of the right side, that the same description will suffice (p. 117). The cardiac nerves are three in number on the left as on the right side, viz., superior, middle, and inferior, but they present some differences. The s^iperior cardiac nerve has a similar course in the neck on both sides ; but the left in entering the chest lies between and parallel to the carotid and subclavian arteries. The middle cardiac nerve unites frequently with the next, and passes beneath tlie subclavian artery to the deep cardiac plexus. The inferior cardiac nerve is generally a small branch, wliich enters the thorax conjoined with the preceding, to end in the cardiac plexus. Section XI. DISSECTION OF THE PHARYNX. The pharynx, or the commencement of the alimentary passage, can be examined only when it has been separated from the rest of the head ; and it will therefore be necessary to cut througli the base of the skull in the manner mentioned below, so as to have the anterior half, with the pharynx connected to it, detaclied from the posterior half. Dissection. The block being removed from beneatli the neck, the head is to be ))laced downwards, so that it may stand on the cut edge of the skull. Next the trachea and oesophagus, togetlier with the vagus and PREPARATION OF PHARYNX. 123 sympathetic nerves, are to be cut near the first rib, and all are to be sepa- rated from the spine as high as the basilar process of the occipital bone ; and without injuring, on the left side, the vessels and nerves near the skull. For the division of the skull turn upwards the inner surface of the base, and make the following incisions in the posterior fossa. On the right side a cut, with the chisel, is to be carried along the line of union of the petrous part of the temporal with the occipital bone. On the left side an- other cut with the chisel is to be made in the same direction, but through the occipital bone internal to the foramen jugulare and the inferior petrosal sinus : this is to begin rather behind that foramen, and to end opposite the one on the other side. The skull is to be sawn through vertically on the left side close behind the mastoid part of the temporal bone, so that the incision shall meet tlie outer end of the cut made with the chisel. Finally placing the skull again upside down, let the student chisel through the basilar process of the occipital bone between the attachments of the pharynx and the muscles of the spinal column, the instrument being directed backwards. The base of the skull is now divided into two parts (one having the pharynx attached to it, the other articulating with the spine), which can be readily separated with a scalpel. The spinal column with the piece of the occipital bone connected with it should be set aside, and kept for after examination. Dissection of the -pharynx (fig. 28). Let the student take the anterior part of the divided skull, and, after moderately filling the pharynx with tow, fasten it with hooks on a block, so that the oesophagus may be pen- dent and towards him. On the left side of the pharynx a different view from that of the right side may be obtained of the cranial and sympathetic nerves near the skull (p. 112), when some loose areolar tissue, and the styloid process with its muscles, have been removed : if the lower ends of the nerves are fixed with pieces of thread, a more satisfactory examination can be made of them. Afterwards the dissector may proceed to remove the fascia from the constrictor muscles of the right side (fig. 28), in the direction of the fibres — these radiating from the side to the middle line. The margins of the two lower constrictor muscles (middle and inferior) are to be defined. Beneath the lower one near the larynx, will be found the recurrent nerve with vessels ; whilst intervening between the middle and superior, are the stylo-pharyngeus muscle and the glosso-pharyngeal nerve. To see the attachment of the superior constrictor to the lower jaw and the ptery go-maxillary ligament, it will be necessary to cut through the in- ternal pterygoid muscle of the right side. Above the upper fibres of this constrictor, and near the base of the skull, are two small muscles of the palate (F and H) entering the pharynx : one — tensor palati, lies between the internal pterygoid plate and muscle ; and the other — levator palati, is farther in, and larger. The PHARYNX is situated behind the nose, mouth, and larynx. Its extent is from the base of the skull to the cricoid cartilage of the larynx, where it ends in the oesophagus. In form it is somewhat conical, with the dilated part upwards ; and in length it measures from five to six inches. The tube of the pharynx is incomplete in front, where it communicates with the cavities above mentioned, but is quite closed behind. On each side of it are placed the trunks of the carotid arteries, wdth the internal 124 DISSECTION OF THE PHARYNX. jugular vein and the accompanying cranial and sympathetic nerves. Behind it is the spinal column, covered by muscles, viz., longus colli and rectus capitis anticus major. In front the pharynx is united to the larynx, the hyoid bone and the tongue, and to the bony framework of the nasal cavity ; but behind it is unattached, and is formed chiefly of thin, fleshy strata. In the posterior wall are contained elevator and constrictor muscles ; and at the u|)per part the bag is further completed by an aponeurotic expansion which fixes it to the base of the skull. The whole is lined by mucous membrane. The aponeurosis of attachment is seen at the upper part of the pharynx, where the muscular fibres are absent, to connect the tube to tlie base of the skull, and to complete the posterior boundary. Superiorly it is fixed to the basilar process of the occipital, and the petrous pai-t of the temporal bone, as well as to the cartilage between the two ; but inferiorly it becomes thin, and extends between the muscular and mucous strata. On this mem- brane some of the fibres of the constrictor muscles terminate. The CONSTRICTORS are three thin muscles, which are arranged like scales, the lower partly overlaying the middle, and the middle the upper. The inferior constrictor (fig. 28, ^), the most superficial and lowest, arises from the side of the cricoid cartilage ; from the oblique line and upper and lower borders of the thyroid cartilage, and from the part of the latter which is behind the oblique line. The origin is small when com- pared with the insertion, for the fibres are directed backwards, radiating, and are inserted into a raphe along the middle line, where it meets the corresponding muscle of the opposite side. The outer surface of the muscle is in contact with the sheath of the carotid artery, and with the muscles covering the spinal column. The lower border is straight, and is continuous with the fibres of the oesopha- gus ; whilst the upper border overlaps the fibres of the middle constrictor (b). The recurrent nerve and vessels (^) enter beneath the lower border. The middle constrictor (fig. 28 ^) has nearly the same shape as the pre- ceding, that is to say, it is narrowed in front and expanded behind. Its fibres arise from the great cornu of the os hyoides, from the small cornu of the same bone, and from the stylo-hyoid ligament. From this origin the fibres radiate, and are blended along the middle line with the other muscles. The surfaces have connections similar to those of the preceding con- strictor. The upper border is separated from the superior constrictor by the stylo-pharyngeus muscle d, and ends on the ajjoneurosis of the pharynx, about an inch from the base of the skull. The lower border descends beneath the inferior constrictor ; and opposite the interval between the two is the up[)er laryngeal nerve (^). The superior constrictor (fig. 28 ^) is the least strong of the three muscles, and wants the usual conical form. Its origin is extensive, and is connected successively, from above down, with the inner surface of the internal pterygoid plate (the lower third or less), witli the pterygo-maxil- lary ligament, with tlie posterior part of the mylo-hyoid ridge of the lower jaw, and with the mucous membrane of the mouth and the side of the tongue. The fleshy fibres pass backwards, and are inserted on the aponeu- rosis of the pharynx, as well as into tlie raphe along the middle line. The parts in contact externally with this muscle are, the deep vessels and nerves of the neck ; and internally it is lined by the aponeurosis and the mucous membrane. The upper border consists of arclied fibres which CONSTRICTOR MUSCLES. 125 are directed backwards from tlie pterygoid plate; and above it the levator palati muscle f is seen. The lower border is overlaid by the middle con- strictor muscle. The attachment to the pterygo-maxillary ligament cor- responds with the origin of the buccinator muscle i. Fisr. 28. Muscles : A. Inferior constrictor. B. Middle constrictor, c. Upper constrictor. D. Stylo-pharyngeus. F. Levator palati. H. Tensor palati. I. Buccinator. K. Hyo-glossus. Nerves : 1. Glosso-pharyngeal. 2. Hypo-glossal. 3. Superior laryu^eal. 4. External laryngeal. 5. Recurrent laryngeal. 6. Gustatory nerve. Ekternai, View of the Pharynx (Illustrations of Dissections) contracting will Action of constrictors. The muscles of both sides diminish the size of the pharynx ; and as the anterior attachments of the lower muscles are nearer together than those of the upper, the tube will be contracted more behind the larynx than near the head. In swallowing the morsel is seized first by the middle constrictor, and is delivered over to the inferior, by which it is conveyed to the oesopha- gus : both muscles act involuntarily. By the contraction of the upper muscle the space above the moutli will be narrowed, so that the soft palate being raised, the upper portion of the pharyngeal space can be shut off from the lower. 126 DISSECTION OF THE PHARYNX. Dissection (fig. 29). Open the pharynx by an incision along its mid- dle, and, after removing the tow from the interior, keep it open with hooks: a better view of the cavity will be obtained by partly dividing the occipital attachment on each side. The mucons membrane is to be care- fully removed below the dilated extremity of tlie Eustachian tube on the right side, for the purpose of finding some pale muscular fibres, salpingo- pharyngeus C, which descend from it. The ELEVATORS of the pharynx are two in number on each side — an external (stylo-pharyngeus), and an internal (salpingo-pharyngeus). The stylo-pharyngeiis (external elevator) may be read again with the pharynx. Its description is given in p. 106. Salpingo-pharyngeus, C (internal elevator). This little band is fixed by tendon to the lower border of the cartilage of tlie Eustachian tube near the orifice. Its fieshy fibres end below by joining those of the palato- pharyngeus Q. If the part is not tolerably fresh the muscle may not be visible. Action. This thin muscle elevates the upper and lateral part of the pharynx above the spot where the large external elevator enters the wall; but it is probably used chiefly in opening the Eustachian tube in swal- lowing. The interior of the pharynx (fig. 29) is wider from side to side tlian from before back, and its greatest width is opposite the hyoid bone; from that spot it diminishes both upwards and downwards, but much more rapidly in the latter than in the former direction. Tlirough the part of the passage above the mouth the air moves in respiration ; wliilst through that below the mouth both air and food are transmitted — the air passing to the aperture of the windpipe, and the food to the oesophagus. In it the following objects are to be noticed : — At the top are situate the posterior apertures, G, of the nasal cavity, which are separated by the septum nasi; and below them hangs the soft palate, partly closing the cavity of the mouth. By tlie side of each nasal aperture is the trumpet-shaped end of the Eustachian tube, F. Below the soft palate, the opening into the mouth — isthmus faucium, H, is to be recognized; and on each side of this is the tonsil, k, which is placed in a hollow between two prominences named pillars of the soft palate — the one, i, proceeding from the soft palate to the side of the tongue, and the other, l, from the same part to the side of the pharynx. Next in order, below the mouth, comes the aperture of the larynx, n; and close in front of it is the epiglottis, or the valve which assists to close that opening during deglutition. Lowest of all is the opening, o, from the pharynx into the oesophagus. The apertures into the pharynx are seven in number, and have the following position and boundaries : — The posterior openings of the ?iasal fossce, G, are oval in form, and measure about an inch from above down, but only half an inch across. Each is constructed in the dried skull by tlie sphenoid and palate bones above, and by the palate below ; by the vomer inside, and the internal pterygoid plate outside; and it is lined by mucous membrane. The Eustachian tube, F, is a canal, partly osseous, partly cartilaginous, by which the tympanic cavity of the ear communicates with the exter- nal air. If the mucous membrane be removed from the tube on the right side, the cartilaginous part appears to be nearly an inch long. It is narrow OPENINGS OF PHARYNX. 12T superiorly, where it is fixed to the margins of a groove between the petrous part of the temporal and the sphenoid bone ; but it increases in width as it is directed downwards to the pharynx, and ends by a wide aperture inside the internal pterygoid plate, on a level with the inferior meatus. Its opening in the pharynx is oval in form; and the inner side, which is larger than the outer, projects forwards, giving rise to a trumpet-shaped mouth. Fig. 29. A. Levator palati. B. Tensor palati. c. Salpingo-pharyngeus. D. Azygos uvulae. B. Internal pterygoid muscle. F. End of the Eustachian tube. G. Posterior uaris. H. Mouth cavity. I. Anterior pillar of the fauces. K. Apertures of the tonsil. L. Posterior pillar of the fauces. N. Opening of the larynx. o. Opening of the oesophagus. p. Uvula. Q. Superficial part of Palato-pharya- geus. Internal View of the Pharnyx (Illustrations of Dissections). Muscles of the Palate, and NAMED Parts. This part of the tube is constructed by a triangular piece of cartilage, whose margins are bent downwards so as to inclose a narrow space; but at the under aspect the cartilage is deficient, and the wall is formed by fibrous membrane. Closely united to the pterygoid plate, the tube is covered by the mucous membrane; and through it the mucous lining of the cavity of the tympanum is continuous with tliat of the pharynx. The space included between the root of the tongue and tlie arches of the soft palate on opposite sides is called the fauces. It is wider below than above; and on each side lies the tonsil. 128 DISSECTION OF THE PHARYNX. The isthmus faucium^ h, is the narrowed aperture of communication between tlie mouth and the fauces, whose size is altered by the elevated or pendent position of the soft palate. Laterally it is bounded by the anterior arches of the soft palate, which are named jo?7/rtrs of the fauces. The aperture of the larynx^ N, is wide in front, where it is bounded by the epiglottis, and pointed behind between the arytasnoid cartilages. The sides are sloped from before back, and are formed by folds of the mucous membrane extending between the aryt^enoid cartilages and the epiglottis. Posteriorly it is limited by the cornicula laryngis, and by the arytienoid muscle covered by mucous membrane. During respiration this aperture is unobstructed, but in the act of deglutition it is closed by the epiglottis. The opening into the cesophagus, o, is the narrowest part of the pha- rynx, and is opposite the cricoid cartilage and the fifth cervical vertebra. Internally the mucous membrane in the oesophagus is paler than that in the pharynx : and externally the point at which the pharynx ends is marked by a slight contraction, and by a change in the direction of the muscular fibres. The SOFT PALATE, Q (velum pendulum palati), is a movable structure between the mouth and the pharynx, which can either close the opening of the mouth, or cut off the passage to the nose, according as it is de- pressed or elevated. In the usual position of the soft palate (the state of relaxation) the anterior surface is somewhat curved, and is continuous with the roof of the mouth, whilst the opposite surface is convex and turned to the pharynx. The upper border is fixed to the posterior margin of the hard palate ; and each lateral part joins the pharynx. The lower border is free, and presents in the centre a conical pendulous part — the uvula^ p. Along its middle is a slight ridge, indicative of the original separation into two halves. Springing from the lower part of the soft palate, near the uvula, are two folds on each sides, containing muscular fibres, which are directed down- wards on the sides of the fauces. These are named arches ov pillars of the palate, and are distinguished from one another by their relative position. The anterior, i, readies from the fore part to the side of the tongue near the middle ; and the posterior, l, longer than the other, is continued from the lower border to the side of the pharynx. As they diverge from their origin to their termination, they limit a triangular space in which the ton- sil lies. The velum consists of an aponeurosis, with muscles, vessels, nerves, and mucous glands ; and the whole is enveloped by the mucous membrane. Dissection Some of the muscles of the palate are readily displayed, but others require care in their dissection. On the right side the two principal muscles of the soft palate — the ele- vator and tensor, are very plain. These have been partly dissected on the right side ; but to follow them to their termination, let the upper attach- ment of the pharynx on the same side, and the part of the superior con- strictor wliich arises from the internal pterygoid plate, be cut through. The levator will be fully laid bare by the removal of the mucous mem- brane, and a few muscular fibres covering its lower part. The tendon of the tensor palati should be followed round the hamular process of the pterygoid plate ; and its situation in the palate beneath the levator should be made evident. The position of the Eustachian tube with respect to those muscles should be ascertained. MUSCLES OF PALATE. 129 On the left side, the mucous membrane is to be raised with great care from the posterior surface of the palate, to obtain a view of the superficial muscular fibres. Immediately beneath the mucous covering are some fine transverse fibres of the palato-pharyngeus muscle; and beneath tliom, in the middle line, are the longitudinal fibres of the azygos uvuhe. A deeper set of fibres of the palato-pharyngeus is to be followed, on the right side, beneath the levator and iizygos muscles. The student should remove next the mucous membrane from tlie mus- cular fibres contained in the arches of the palate, and shoidd follow these upwards and downwards. In order to see them in the anterior fold, it will be necessary to take the membrane from the anterior surface of the palate. If the part is not tolerably fresh, some of the paler fibres may not be visible. Aponeurosis of the soft palate. Giving strength to the velum is a thin but firm aponeurosis, which is attached to the hard palate. This mem- brane becomes thinner as it descends in the velum; and it is joined by the tendon of the tensor palati muscle. The MUSCLES of the soft palate are four on each side, — an elevator and tensor; with the palato-glossus and palato-pharyngeus, which act as de- pressors. In addition there is a small median azygos muscle. The LEVATOR PALATI (fig. 29, ^) is a thick, roundish muscle, which is partly situate outside the pharynx. It arises from the under surface of the apex of the petrous portion of the temporal bone (fig. 30, ^), and from the inner and hinder part of the cartilage of the Eustachian tube. The fibres enter the pharynx above the superior constrictor, and then spread out in the soft palate, where they join along the middle line with those of the muscles of the opposite side. Outside the pharynx this muscle rests against the Eustachian tube. In the palate it forms a stratum that reaches the whole depth of that struc- ture, an,d is embraced by two planes of fibres of the palato-pharyngeus (*). Action. It tilts backwards the free edge of the soft palate towards the pharynx so as to enlarge the isthmus faucium, and to shut off with the contracted pharynx the nose openings. In swallowing the palate is raised, and is arched over the bolus passing from the mouth to the pharynx. For its action on the Eustachian tube, see Tensor palati. The TENSOR vel circumflexus palati (fig. 29, ^) arises like the preceding outside the pharynx, and is a thin riband-like band, situate between the internal pterygoid plate and muscle. About one inch and a half wide at its origin, it is attached to the slight depression (scaphoid fossa) at the root of the internal pterygoid plate, to the outer and forepart of the Eustachian tube, and still further out to the spinous process of the sphenoid, and the vaginal (tympanic) process of the temporal bone. In- feriorly the fleshy fibres end in a tendon which, entering the pharynx between the attachments of the buccinator muscle, is reflected round the hamular process (fig. 30, ^), and is inserted into about one-third of an inch of the posterior border of the palate, viz., from the central spine to a pro- jecting point; and inferiorly into the aponeurosis of the velum. As the tendon winds round the bone, it is thrown into folds; and be- tween the two is a bursa. In the soft palate it lies beneath the levator muscle. The Eustachian tube is directed inwards between this muscle and the preceding. Action. Acting from the skull the muscle will fix and make tense the 9 130 DISSECTION OF THE PHARYNX latenil part of the soft palate; but its movements will be very limited, seeing that the tendon is inserted partly into the palate bone. Fiff. 30. 1. Azygos uvulae. 2. Tensor palati. 3. Levator palati. 4. Palato-pharyngeus — upper end. 6. External pterygoid. If the soft palate is fixed by the depressor muscles, the levator and tensor, and the salpingo-pharyngeus, taking their fixed points below, open the Eustachian tube in swallowing. The PALATO-GLOSSUS MUSCLE (coustrictor isthmi faucium) is a small, pale band of fibres, which is contained in the anterior arch, i, of the soft palate. It is connected inferiorly with the lateral surface and the dorsum of the tongue ; from this spot the fibres ascend beibre the tonsil to the anterior aspect of the soft palate, where they form a thin muscular stratum, and join those of the fellow muscle along the middle line. At its origin the muscle is blended with the glossal muscles, and at its insertion it is placed before the tensor palati. Action. The palato-glossus narrows the isthmus of the fauces ; the mus- cles of opposite sides moving inwards towards each other, and separating from the mouth the morsel to be swallowed. When the tongue is fixed the muscle will render tense and draw down the soft palate. The PALATO-PHARYNGEUS is much larger in size than the preceding, and gives rise to the eminence of the posterior pillar, l, of the soi"t palate. Tlie muscle is attached below to the posterior border of the thyroid carti- lage, some fibres blending witli the contiguous portion of the pharynx ; and it decussates across the middle line with corresponding fibres of the muscle of the opposite side (Merkel).^ Ascending thence behind the tonsil, the fibres enter the side of the palate, and separate into two layers (fig. 30, *). The posterior, thin and in contact with the mucous mem- brane, joins at the middle line a like offset of its fellow. Tiie deeper or anterior stratum, much the strongest, enters the substance of the palate between the levator and tensor, and joins at the middle line the corre- spcmding part of the opposite muscle, whilst some of the upper fibres end on the aponeurosis of tlie palate. ' Di:. Morkel, in the work before referred to, states tliat tliis muscle has no firm fixed attachment below, and that it ends altogether in the wall of the pharynx, decussating with the muscle of the opposite side. This assertion does not accord with my experience. THE TONSIL. 131 In the palate the muscle incloses the levator palati and azygos uvulae between its two strata. Action. Taking its fixed point at the tliyroid cartilage the muscle de- presses and makes tense the soft palate. During the act of swallowing both muscles move back the lower edge of the soft palate towards the pliarynx; and approaching each other, form an oblique plane for the downward direction of the food ; in that state the uvula lies in the interval between the two. The AZYGOS uvuLiE (fig. 29, ^) is situate along the middle line of the velum near the posterior surface. The muscle consists of two narrow slips of pale fibres, which arise from the spine at tlie posterior border of the hard palate, or from the contiguous aponeurosis, and end inferiorly in tlie tip of the uvula. Behind this muscle, separating it from the mucous membrane, is the thin stratum of the palato-pharyngeus. Action. Its fibres elevate the uvula, shortening the mid part of the soft palate, and direct that process backwards. Tlie tonsil, k, is a collection of follicular capsules resembling those on the dorsum linguop, which is placed close above the base of the tongue, and between the arches of the soft palate. Each is roundish in shape, but variable in size ; and apertures are apparent on its surface. Externally the tonsil is situate opposite the superior constrictor muscle and the angle of the lower jaw^ ; and when enlarged it may press against the internal carotid bloodvessel. The apertures on the surface lead to rounded terminal recesses or hol- lows w^hich are lined by mucous membrane. Around each recess is a layer of small closed capsules, which are seated in the tissue beneath the mucous membrane, i\nd are filled with a grayish substance containing cells and nuclear-looking bodies. No openings from the capsules are to be recognized in the recesses. Its arteries are numerous and are derived from the facial, lingual, as- cending pharyngeal, and internal maxillary branches of the external carotid. Its i'>eins have a plexiform arrangement on the outer side. Nerves are furnished to it from the fifth and glosso-pharyngeal nerves. The mucous membrane of the pharynx is continuous anteriorly with the lining of the mouth, nose, and larynx. Covering the soft palate and its numerous small glands (palatine), the membrane is continued to the ton- sils on each side, and is prolonged by the Eustachian tube to the tym- panum. In front of each aryta^noid cartilage it incloses a mass of muci- ])arous glands (arytnenoid). Inferiorly, it is continued by the oesophagus to the stomach. The mucous membrane is provided with more glands in the upper, than in the lower part of the pharynx ; and its character, near the diflferent ai)ertures, resembles that of the membrane lining the cavities communi- cating wMth the pharynx. Its epithelium is scaly below the nares (llenle) ; but is columnar and ciliated above that spot, where only the air is trans- mitted. Beginning of the oesophagus. Tiiis tube is much smaller than the pha- rynx, and the walls are flaccid. For the commencement, and its connec- tions in the neck, see p. 121. The gullet consists of two layers of muscular fibres, with a lining of mucous membrane. The external layer is formed of longitudinal fibres, which begin opposite the cricoid cartilage by three bundles, anterior and two lateral ; the former is attached to the ridge at the back of the carti- 132 CAVITY OF THE MOUTH. lage, and the others join the inferior constrictor. The internal layer^ on the other hand, is formed of circular libres, which are continuous with those of the inferior constrictor. The structure of the oesophagus is de- scribed more fully in the dissection of the thorax. Section XII. CAVITY OF THE MOUTH. The cheeks, the lips, and the teeth are to be examined with the mouth, as all may be considered accessory parts. The Mouth. The cavity of the mouth is situate below that of the nose, and extends from the lips in front to the isthmus of the fauces be- hind. Its boundaries are partly osseous and partly muscular, and its size depends upon the position of the lower jaw bone. When the lower jaw is moderately removed from the upper, the mouth is an oval cavity with the following boundaries. The roo}\ concave, is constituted by the hard and soft palate, and is limited anteriorly by the arch of the teeth. In the Hoor is the tongue, bounded by the arch of the lower teeth ; and beneath the tip of that body is the fraenum linguae, with the sublingual gland on each side. Each lateral boundary consists of the cheek and the ramus of the lower jaw ; and in it, near the second molar tooth in the upper jaw, is the opening of the parotid duct. The anterior opening of the mouth is bounded by the lips ; and the posterior corresponds with the anterior pil- lars of the soft palate. The mucous membrane is less sensitive on the hard than the soft parts bounding the mouth ; it lines the interior of the cavity, and is reflected over the tongue. Anteriorly it is continuous with the tegument, and pos- teriorly with the lining of the pharynx. The epithelium covering the membrane is of the scaly variety. Between each lip and the front of the coiTesponding jaw the membrane forms a small fold — fraenulum. On the bony part of the roof it blends with the dense tissue (gums) covering the vessels and nerves. On the soft palate it is smooth and thinner, and along the middle of the palate is a ridge which ends in front in a small papilla. In the floor of the mouth the membrane forms the fra'num linguae beneath the tip of the tongue, and sends tubes into the openings of the Whartonian and sublingual ducts ; whilst on each side of the fnenum it is raised into a ridge by the subjacent sublingual gland. On the interior of the cheek and lips the mucous lining is smooth, and is separated from the muscles by small buccal and labial glands. Over the whole cavity, but especially on the lips, are papilla? for the pur})Ose of touch. The CHEEK extends from the commissure of the lips to the ramus of the lower jaw, and is attached above and below to the alveolar process of the jaw on the outer aspect. The chief constituent of the cheek is the fleshy part of the buccinator muscle ; on the inner surface of this is the mucous membrane ; and on the outer the integuments, with some muscles, vessels, and nerves. Tiie parotid duct perforates the cheek near the second molar tooth of the upper jaw. CAVITY OF THE NOSE. 133 The LIPS surround the opening of the mouth ; they consist chiefly of the fleshy part of the orbicularis oris muscle, covered externally by integu- -ment, and internally by mucous membrane. The lower lip is the larger and more movable of the two. Between the muscular structure and the mucous covering lie the labial glands ; and in the substance of each lip, nearer the inner than the outer surface, and at the line of junction of the two parts of the orbicularis, is placed the arch of the coronary artery. Teeth. In the adult there are sixteen teeth in each jaw, which are set in the alveolar borders in the form of an arch, and are surrounded by the gums. Each dental arch has its convexity turned forwards ; and, commonly, the arch in the maxilla overhangs that in the mandible when the jaws are in contact. The teeth are similar in the half of each jaw, and have received the following names : the most anterior two are incisors, and the one next behind is the canine tooth ; two, still farther back, are the bicuspids ; and the last three are molar teeth. Moreover, the last molar tooth has been called also " dens sapientije," from the late period of its appearance. The names applied to the teeth indicate very nearly the part they perform in mastication ; thus the incisor and canine teeth act as dividers of the food, wiiilst the bicuspid and molar teeth serve to grind the aliment. The several parts of the teeth, viz., the crown, fang, and neck ; the general and special characters of those parts in the diiferent groups of teeth ; and the structure of the different components of a tooth, must be referred to in some general treatise on anatomy. Section XIII. DISSECTION OF THE NOSE. To obtain a view of the interior of the nose, it will be necessary to make a longitudinal section through the base of the skull. Whilst the student is examining the boundaries of the nose he will derive advantage from the use of a vertical section of a dried nasal cavity. Dissection. Before sawing the bone, the loose part of the lower jaw on the right side should be taken away ; further, the tongue, hyoid bone, and larynx, all united, may be detached from the opposite half of the lower jaw, and laid aside till the dissector is ready to use them. On the right side of the middle line saw through the frontal and nasal bones, the cribriform plate of the ethmoid, and part of the body of the sphenoid bone, without letting the saw descend into the nasal cavity. Next the roof of the mouth is to be turned upwards, and the soft parts are to be divided on the right of the median line opposite the cut in the roof of the nose. The saw is then to be carried through the floor of the nose and the body of the sphenoid bone in such a direction as to come into the incision above. The piece of the skull is now separated into two parts, right and left; the right half will serve for the examination of the meatuses, and the left wnll show the septum nasi, after the mucous membrane has been removed. The CAVITY OF THE NOSE is placed in the centre of the bones of the face, being situate above the mouth, below the cranium, and between the 134 DISSECTION OF THE NASAL CAVITY. orbits. This space is divided into two parts — nasal fossae — by a vertical partition. Each fossa is larger below tlian above ; and is flattened in form, so that the measurement from before back or Jibove down exceeds much that from within out. It communicates with both the face and tlie pharynx by apertures named nares, and lias also apertures of communication with the sinuses in the surrounding bones, viz., frontal, ethmoid, sphenoid, and superior maxillary. The student has to examine in each fossa a roof and floor, an inner and outer wall, and an anterior and posterior 0[)ening. The roof is somewhat arched, and is formed by the cribriform plate of the ethmoid bone in tlie centre ; by the frontal and nasal bones, and the cartilages in front ; and by tlie body of the sphenoid, the sphenoidal spongy bone, and the os palati, at the posterior part. In the dried skull many apertures exist in it ; most are in the ethmoid bone for the branches of the olfactory nerve with vessels, and one for the nasal nerve and vessels ; in the front of the body of the sphenoid is the opening of its sinus. The floor is slightly hollowed from side to side, and in it are the palate and superior maxillary bones — their palate processes. Near the front in the dry skull is the incisor foramen leading to the anterior pala- tine fossa. Tlie inner boundary (septum nasi) is partly osseous and partly carti- laginous. The osseous part is constructed by the vomer, by the per|)en- dicular plate of the ethmoid bone, and by those parts of the frontal and nasal with which this last bone articulates. The irregular s[)ace in front in the prepared skull is filled in the recent state by the triangular carti- lage of the septum, which forms part of the partition between the nostrils, and supports the cartilages of the anterior aperture. Fixed between the vomer, the ethmoid plate, and the nasal bones, this cartilage rests ante- riorly on the median ridge between the suj)erior maxillie, and projects even between the cartilages of each nostril. The septum nasi is commonly bent to one side. The outer boundary has the greatest extent and the most irregular sur- face. Six bones enter into its formation, and they come in the following order from before backwards : the nasal and superior maxillary ; tlie small OS unguis with the lateral mass of the ethmoid bone ; and posteriorly the ascending part of the palate bone, with the internal pterygoid platen of the sphenoid bone : of these, the nasal, ungual, and ethmoidal reach only about half way from the roof to floor, whilst the others extend the whole depth. Altogether in front of the bones, the lateral cartilages may be said to con- struct part of this boundary. On this wall are three convoluted osseous pieces, named spongy or tur- binate bones, (fig. 31), wliich project into the cavity : — the two upper (') and (^), are processes of the ethmoid, but the lower one (^), is a separate bone — the inferior spongy. The spongy bones are confined to a certain y)ortion of the outer wall, and their extent would be limited by a line con- tinued nearly vertically u[)wards to the roof of the cavity from both the front and back of the hard j)alate. Between each turbinate bone and the wall of the nose is a longitudinal hollow or meatus ; and into these hollows the nasal duct and the sinuses of the surrounding bones open. The meatuses are the spaces arched over by the spongy bones ; and as the bones are limited to a certain part of the outer wall, so are the spaces beneath them. The upper one (fig. 31, *) is the smallest and straightest of the three SPONGY BONES AND MEATUSES 135 meatuses, and occupies the posterior half of the space inchided by the ver- tical lines before mentioned. Into it the posterior ethmoidal sinuses open at the front ; and at its posterior part, in the dried bone, is the spheno- pahitine foramen by which the nerves and vessels enter the nose. The middle meatus (fig. 31, ^) is longer than the preceding; it is curved upwards in front, and reaches all across the space referred to on the outer wall. Anteriorly it communicates by a funnel-shaped passage (infundibulum) with the frontal sinus and the anterior ethmoidal cells ; and near its middle is a small aperture, which leads into tlie cavity of the upper jaw. The inferior meatus (fig. 31,*) is straighter than the middle one, and rather exceeds the width of the included space on the outer wall ; and Fiff. 31. 1. Upper spongy bone. 2. Middle spongy bone. 3. Inferior spongy bone. 4. Square part of the ethmoid bone. 6. Upper meatus. 7. Middle meatus. 8. Lower meatus. 9. Rudimentary fourth meatus. 10. Vestibule of the nasal cavity. The woodcut shows also the aper- tures of the glands of the nose. Spongy Bones and Meatuses of the Nasal Cavity. when the bone is clothed by the mucous membrane it extends still further forwards. In its front is the opening of the ductus ad nasum. Occasionally there is a small fourth or rudimentary meatus above the rest (fig. 31, '), which communicates with a posterior ethmoidal cell. The naves. In the recent condition of the nose each fossa has a dis- tinct anterior opening in the face, and another in the pharynx ; but in the skeleton there is only one common opening in front for both sides. These apertures, and the parts bounding them, have been before described (pp. 42 and 126). The mucous membrane lining the nasal fossa is called the pituitary or Schneiderian membrane ; and from its blending with the periosteum it acquires much strength. It is continuous with the integument at the nos- tril, and with the membrane lining the pharynx through the posterior opening : moreover, it is also continuous with the mucous membrane of the eyeball, and with that of the different sinuses, viz., frontal, ethmoidal, sphenoidal, and maxillary. The foramina in the dry bones, which transmit nerves and vessels, are entirely closed by the membrane, viz., the incisor, spheno-palatine, the holes in the cribriform plate, and the foramen for the nasal nerve and 136 DISSECTION OF THE NASAL CAVITY, vessels ; but the apertures that lead to the sinuses and the orbit are only somewhat diminished by the lining they receive. The membrane is stretched over the opening of the ductus ad nasum, forming a flap or valve to close the aperture. The characters of the membrane in the lower or respiratory part of the nose differ greatly from those of the same layer in the olfactorial region near the roof. In the lower region of the nose, through which the air passes to the lungs, the membrane is thick, and closely united to the subjacent perios- teum and pericliondrium ; and on the margins of the two inferior spongy bones it is projected somewhat by the large submucous vessels, so as to increase the extent of surface. In the canals and sinuses it is very thin. Near the nostril it is furnished with papillae, and small hairs (vibrissae). The surface is covered by the apertures of branched mucous glands, which are in greatest abundance, and of largest size, about the middle and posterior parts of the nasal fossa. In the lower part of the nose, and in the sinuses, the epithelium is of the columnar ciliated kind; but it becomes laminated or scaly in the dilatation or vestibule inside the nostril (fig. 31, ^0). Fig. 32. A. 1. Columnar epithelium at the free surface. 2. Granular or middle layer of the same. 3. Deepest layer of elouj,'ated cells placed vertically. 4. Secreting tubular glands. B. a. Pieces of the columnar epithelium greatly en- larged. 6. Olfactorial cells amongst the epithelium parti- cles. Magnified Vertical Section of the Mucous Membrane of the Nose (altered from Henle). The olfactory region (fig. 32) is situate at the top of the nasal cavity, and is confined to the surface of the roof formed by the cribriform plate of the ethmoid; to a portion of the outer wall constructed by the lateral mass of the ethmoid bone: and to a corresponding extent of the septum, viz., about one-tliird. Tlie mucous membrane in the olfactory region receives the olfactory nerve, and is tlierefore tiie seat of the sense of smell. It differs much from that in the lower portion of the nose, for it is less strong and vascu- lar; and is of a yellowish color, wliich is due to pigment in tiie epithelium and the glands. Tlie epithelium (fig. 32 a) is thicker but softer here than lower in the cavity, and it is columnar on the surface, but not ciliated. Beneath the OLFACTORY NERVE, 137 surface layer are strata of granules and ovalish cells (^), amongst which sink the pointed or attached ends of the pieces of epithelium. Around the pieces of the columnar epithelium stand numerous bodies named olfactorial cells by Schultze (fig. 32 b. *). They consist of small spindle-shaped nucleated cells, with a rounded filament prolonged from each end towards the attached and free surfaces of the mucous membrane : that to the free surface, the larger, ends on a level with the pieces of the columnar epithelium. But the connections of the deeper threads or pro- cesses are unknown ; they have been supposed to unite with the olfactory nerve. The glands in the olfactory region are simple lengthened tubes (fig. 32 A. *) like those in the stomach, but are slightly wavy, and end in the submucous tissue by closed extremities. A flattened epithelium, with colored granular contents, lines the tubes (Henle.) Dissection. At this stage of the dissection, little will be seen of the distribution of the olfactory nerve. If the septum nasi be removed, so as to leave entire the membrane covering it on the opposite side (the left), the filaments of the nerve will appear on the surface, near the cribriform plate. In the membrane, too, near the front of the septum, is an offset of the nasal nerve. The naso-palatine nerve and artery (fig. 33, ^) are to be sought lower down, as they are directed from behind forwards, towards the anterior Fijr. 33. Nerves op the Septum of the Nose. 1. Olfactory bulb and its ramifications on the 3. Naso-palatine nerve from Meckel's ganglion septum. (too lar^e in the cut.) 2. Nasal nerve of the ophthalmic trunk. palatine fossa; the artery is rejidily seen, especially if it is injected, but the fine nerve, which is about as large as a coarse liair, is imbedded in the membrane and will be found by scraping with the point of the scalpel. By cutting through the fore and upper jmrt of the membrane that has been detached from the septum nasi, other branches of the olfactory nerve may be traced on the outer wall of tlie nasal fossa. 138 DISSECTION OF THE HEAD. The OLFACTORY NERVE (fig. 33, ^) fomis a bulb on the cribriform plate of the ethmoid bone, and send8 branches to the olfactory region of the nose througl) the apertures in the roof. These branches are about twenty in number, and are divisible into three sets. An inner set, the largest, descend in the grooves on the septum nasi, and branching, extend over the upper third. A middle set is confined to the roof of the nose. And an external set is distributed on the upper spongy bone, on the anterior square surface of the os ethmoides, and on the fore part of the middle spongy bone. As the branches of the olfactory nerve leave the skull, they receive tubes from the dura mater and pia mater, which are lost in the tissue to which the nerves are distributed. The nerves ramify in the pituitary membrane in tufts of filaments which communicate freely with the con- tiguous twigs, forming a network, but their mode of termination in the tissue is unknown. It has been suggested by Schulze that they join the deep processes or ends of the so-called olfactorial cells ; but this union has not been seen. The olfactory nerve differs in structure from the other cranial nerves ; for its branches are deficient in the white substance of Schwann, are not divisible into fibrillar, and are nucleated and granular in texture. They resemble the ganglionic fibres: and seem to consist of an extension of the nerve substance of the olfactory bulb. The other nerves in the nose will be described in the following section. Bloodvessels. Foi* a statement of the different vessels of the nose, see p. 141. The arteries form a network in the pituitary membrane, and a large submucous plexus on the edge of each of the two lower spongy bones, especially on the inferior. The veins have a plexiform disposition like the arteries, and this is largest on the lower spongy bone and the septum nasi. Section XIV. SPHENO-PALATINE AND OTIC GANGLIA, FACIAL AND NASAL NERVES, AND BRANCHES OF THE INTERNAL MAXILLARY ARTERY. The preparation of Meckel's ganglion and its branches (fig. 34), and of the terminal branches of the internal maxillary artery, is a somewhat ditti- cult task in consequence of the nerves and vessels being contained in osseous canals which require to be opened. As is the case witii other dissections, the student seeks first the branches, and traces these to the ganglion and main trunk. Dissection. The left half of the head is to be used for the display of the ganglion and its branches; but the student may previously acquire some skill by attempting the dissection on the remains of the right side. To lay bare the branches of the palate, detach the soft parts in the roof of the mouth from the bone, until tlie nerves and vessels escaping from the posterior y)alatine foramina are arrived at. Cut off, with a bone forceps, the j)OSterior part of the hard i)alate to a level with the vessels and nerves ; and cleaning these, trace offsets behind into the soft palate, and follow the main pieces forwards to the front of the mouth. Take away without injury to the naso-palatine nerve and vessels (already SPHENO-PALATINE GANGLION. 139 found), the hinder part of the loose piece of mucous membrane before de- tached from the septum nasi, and separate the mucous membrane from the outer wall of the nasal fossa, behind the spongy bones, as high as the spheno-palatine foramen. In reflecting forwards the membrane many branches of vessels and nerves will be seen entering it through the fora- men ; but these may be left for the present, as directions for their dissec- tion will be subsequently given. When the lining membrane of the nose has been removed behind the spongy bones, palatine nerves and vessels will appear through the thin translucent palate bone, and will be readily reached by breaking carefully through it w^ith a chisel. Afterwards the tube of membrane containing the palatine vessels and nerves being opened, these are to be followed down to the soft palate and the roof of the mouth, and upwards to the ganglion which is close to the body of the sphenoid bone. To bring the ganglion fully into view, it will be necessary to saw through the overhanging part of the sphenoid bone, to cut away pieces of the bones surrounding the hollow in which it lies, and to remove with care tlie enveloping fat and the periosteum. The ganglion then appears as a flat- tened reddish-looking body, from which the vidian and pharyngeal nerves pass backwards. Besides the branches referred to, the student should seek two large nerves from the upper part of the ganglion to join the upper maxillary, and smaller offsets to the floor of the orbit. To trace backwards the vidian branch to tlie carotid plexus and the facial nerve, the student must lay open the canal which contains it and its artery in the root of the pterygoid process; and in doing this he must define the small pharyngeal brandies of nerve and artery which are super- ficial to tlie vidian, and lie in the pterygo-palatine canal. At the back of the pterygoid canal, a small branch from the vidian to the plexus on the internal carotid artery is to be looked for. Lastly, the vidian nerve is to be followed into the skull through the cartilage in the foramen lacerum (basis cranii), after cutting away the point of the petrous portion of the temporal bone, and dividing the internal carotid artery; and it is to be pursued on the surface of the temporal bone, beneath the ganglion of the fifth nerve, to the hiatus Fallopii : its junction with the facial nerve will be seen with the dissection of that nerve. The branches of the ganglion to the nose will be found entering the outer surface of the detached mucous membrane opposite the spheno-pala- tine foramen, with corresponding arteries. One of these nerves (naso- palatine), before dissected in the membrane of the septum, is to be isolated, and to be followed forwards to where it enters the floor of the nose. The branches of the internal maxillary artery with the nerves are to be cleaned at tiie same time. The SPHENO-PALATINE GANGLION (fig. 34, ') (ganglion of Meckel) occupies the spheno-maxillary fossa, close to the spheno-palatine foramen, and is connected with the branches of the superior maxillary nerve to the palate. The ganglionic mass is somewhat triangular in form, and of a reddish-gray color. It is situate for the most part, behind the branches (spheno-palatine) of the superior maxillary nerve to the palate, so as to sur- round only part of their fibres ; and it is prolonged posteriorly into the vidian nerve. Meckel's ganglion resembles the other ganglia in connec- tion with the fifth nerve in having sensory, motor, and sympathetic offsets or roots connected with it. The Branches of the ganglion are distributed for the most part to the 140 DISSECTION OF THE HEAD. nose and palate, but small offsets are given to the pharynx and the orbit. Other offsets connect it with surrounding nerves. Branches of the nose. The nasal branches, from three to five in num- ber, are for the most part very small and soft, and pass inwards through the spheno-palatine foramen : their distribution is given below : — The superior nasal branches (f t) are distributed in the mucous mem- brane on the two upper spongy bones, and a few filaments reach the back part of the septum nasi. The naso-palatine nerve (nerve of Cotunnius) (fig. 33, ^) crosses the roof of the nasal fossa to reach the septum nasi, and descends on that par- tition to near the front. In the floor of the nose it enters a special canal by the side of the septum, the left being anterior to the other, and is con- veyed to the roof of the mouth, where it lies in the centre of the anterior palatine fossa. Finally, the nerves of opposite sides are united in the mouth, and are distributed in the mucous membrane behind the incisor teeth. On the septum nasi filaments are supplied by the naso-palatine nerve to the mucous membrane. To follow the nerve to its termination, the canal in the roof of the mouth must be opened. Fiff. 34. Nerves op the Nose and Palate. 1. Olfactory nerve. 2. Olfactory bulb giving branches to the nose. 3. Third nerve. 4 Fourth nerve. .0. Fifth nerve. 6. Nasal nerve of the ophthalmic trunk. 7. Meckel's ganglion. S. Vidian nerve. 9. Larger palatino nerve. 10. Smaller palatine nerve, ft Nasal nerve. Branches of the palate. The nerves of the palate, though connected in part with tlie ganglionic mass, are the continuation of the spheno-palatine branches of tjje su])erior maxillary nerve (p. 104). Below the ganglion they are divided into three — large, small, and external. The larffe palatine nerve (anterior) (fig. 34, ^) reaches the roof of the mouth through the largest palatine canal, and courses forwards nearly to tlie incisor teeth, where it joins the naso-palatine nerve. Whilst in the canal, the nerve furnishes two or more filaments {inferior nasal t) to the SPHENO-PALATINE GANGLION. 141 membrane on the middle and lower spongy bones ; in the roof of the mouth it supplies the mucous membrane and glands, and gives an offset to the soft palate. The small jmlatiiie nerve, 10 (posterior), lies in the smaller canal, and ends inferiorly in the soft pahite, and the levator j^alati and azygos uvulje muscles ; it supplies the uvula and tonsil. The external palatine nerve is smaller than the other two, and de- scends in the canal of the same name. Leaving the canal, the nerve is distributed to the velum palati and the tonsil. The pharyngeal branch is very small, and is directed through the pterygo-palatine canal to the mucous membrane of the pharynx near the Eustachian tube, in which it ends. Branches to the orbit. Two or three in number, these ascend through the spheno-maxillary fissure, and end in the fleshy layer of the musculus orbitalis (p. GO). It will be necessary to cut throngh the sphenoid bone to follow these nerves to their termination. Connecting branches. The ganglion is united, as before said, with the spheno-palatine branches of the fiftli nerve (fig. 24, ^), receiving sensory nerve fibres through them ; and through the medium of the vidian, which is described below, it communicates with a motor nerve (facial) and with the sympathetic nerve. The vidian nerve (^) passes backwards through the vidian canal, and sends some small filaments, through the bone, to the membrane of the back of the roof of the nose {upper posterior nasal branches). At its exit from the canal, the nerve receives a soft reddish offset {carotid branch) from the sympathetic on the outer side of the carotid artery. The continuation of the nerve enters the cranium through the cartilaginous substance in the foramen lacerum (basis cranii), and is directed backwards in a groove on the surface of the })etrous part of the temporal bone, where it takes the name of large superficial petrosal nerve (fig. 35, ^). Lastly it is continued through the hiatus Fallopii, to join the gangliform enlargement on the facial nerve. AVhilst in the temporal bone, the vidian receives a twig from the tympjuiic nerve. The vidian nerve is supposed to consist of motor and sympathetic fibres in the same sheath, as in the connecting branches between the sympa- thetic and spinal nerve. Directions. The student may now give his attention to the remaining nerves in the nasal cavity. Dissectioti. The nasal nerve is to be sought in the nose beiiind the nasal bone (fig. 34), by gently detaching the lining membrane, after having cut olf the projecting bone. A branch is given from the nerve to the septum nasi, but probably this, and the trunk of the nerve, will be seen but imperfectly in the present condition of the part. The terminal branches of the internal maxillary artery in the spheno- maxillary fossa have been laid bare in the dissection of Meckel's ganglion, but they may be now completely traced out. The nasal nerve (of the ophthalmic) (fig. 34, ^) has been already seen in the skull and orbit. Entering the nasal fossa by an a})erture at the front of the ethmoid bone, the nerve gives a branch to the membrane of the septum, and is continued in a groove behind the os nasi to the lower margin of this Ijone where it escapes to the surface of the nose in the face (fig. 9, '). 142 DISSECTION OF THE HEAD. Branches. Tlie branch to the septum (fig. 33) divides into fibiments that ramify on the anterior part of tliat partition, and reach nearly to the lower border. One or two jilaments are likewise furnished by the nerve to the mueous membrane on the outer wall of the nasal fossa ; these extend as low as the inferior spongy bone. Terminal branches of the internal maxillary artery. The branches of the artery in the spheno-maxillary fossq,, which have not been examined, are the superior palatine, naso-palatine, pterygo-palatine, and vidian. The superior or descending palatine is the largest branch, and accom- panies the large palatine nerve through the canal, and along the roof of the mouth ; it anastomoses beiiind the incisor teeth wdth its fellow, and with a branch through the incisor foramen. This artery supplies offsets to the soft palate and tonsil tlirough the other palatine canals, and some twigs are furnished to the lining membrane of the nose. In the roof of the mouth the mucous membrane, glands, and gums, receive their vessels from it. The nasal Qv spheno -palatine artery enters the nose through the spheno- palatine foramen, and divides into branches : Some of these are distributed on the spongy bones, and the outer wall of tlie nasal fossa, and supply oif- sets to tlie posterior ethmoidal cells. One long branch, artery of the sep- tum {art. naso. palatino?) runs on the partition between the nasal fossne to the incisor foramen, through which it anastomoses with the superior pala- tine in the roof of the mouth ; this branch accompanies the naso-palatine nerve, and covers the septum with numerous ramifications. 'YXxe pterygo-palatine is a very small branch which, passing backwards through the canal of the same name, is distributed to the lining membrane of the pharynx. The vidian or pterygoid branch is contained in the vidian canal with the nerve of the same name, and ends on the mucous membrane of the Eustachian tube and the upper part of the pharynx. Some small nasal arteries are furnished to the roof of the nasal fossa by the posterior ethmoidal branch of the ophthalmic (p. 56). Also the anterior ethmoidal (internal nasal, p. 57), enters the cavity with the nasal nerve, and ramifies in the lining membrane of the fore part of the nasal chamber as low as the vestibule ; a branch passes to the face between the OS nasi and the cartilage, with its nerve. Other offsets from the facial artery supply the part near the nostril. Veins. Tlie veins accompanying the terminal branches of the internal maxillary artery unite in the spheno-maxillary fossa in the cdveolar plexus. Into this plexus offsets are received from the pterygoid plexus and the infraorbital vein ; and from the plexus a large trunk (anterior in- ternal maxillary) is directed forwards below the malar bone to join the facial vein (p. 40). Beneath the mucous membrane of the nose the veins have a {)lexiform arrangement, as before said. Facial nerve in the temporal bone (fig. 35). This nerve winds through the petrous part of the temporal bone ; and it is followed with difficulty in consequence of the extreme density of the bone, and the ab- sence of marks on the surface to indicate its position. To render this dissection easier, the student should be provided with a temporal bone, in which the course of the facial nerve and the cavity of the tympanum are displayed. FACIAL NERVE IN THE BONE, 143 Dissection. The examination of the nerve is to be begun at the stylo- mastoid foramen, and to be carried forwards from that point. With this view, the side of the skull should be sawn through vertically between the meatus externus and tlie anterior border of tlie mastoid process, so as to open the ])Osterior part of the aqueduct of Fallopius. The nerve will be then seen entering deeply into the substance of the temporal bone ; and it can be followed by cutting away with the bone forceps all the bone pro- jecting above it. In this last step the cavity of the tympanum will be more or less opened, and the chain of bones in it laid bare. The nerve is to be traced onwards along tlie inner side of the tympa- num, till it becomes enlarged, and bends suddenly inwards to the meatus auditorious internus. Tlie surrounding bone is to be removed from that enlargement so as to allow of the petrosal nerves being traced to it ; and the meatus auditorious is to be laid open, to see the facial and auditory nerves in that hollow. The course of the chorda tympani nerve (branch of the facial) across the tympanum will be brought into sight by the removal of the central ear bone, the incus. This nerve may be also followed to the facial througii the wall of the cavity behind, as well as out of the cavity in front. The remaining branches of the facial nerve in the bone are very minute, and are not to be seen ex- cept on a fresh piece of the skull which has been softened in acid. The student may therefore omit the para- graphs marked with an asterisk, till he is able to obtain a part on which a careful examination can be made. The facial nerve (fig. 35, ^) is re- ceived into the internal auditory mea- tus, and entering the aqueduct of Fallopius at the bottom of that hol- low, is conducted through the tem- poral bone to the stylo-mastoid fora- men and the face (p. 48). In its serpentine course tlirough the bone, the nerve is first directed outwards to the inner wall of the tympanum : at that S[)Ot it bends backwards, and is marked by a ganglifbrm swelling (in tu muscen tia gangliformis), to which several small nerves are united. From this swelling the nerve is con- tinued through the arched aqueduct, to the aperture of exit from the bone. The branches of the nerve in the bone serve for the most part to con- nect it with otlier nerves ; but one supplies the tongue, and another the stapedius muscle. * Connecting branches communicate with the auditory and glosso- pharyngeal nerves ; and with two trunks (superior and inferior maxillary) of the fifth nerve. Nerves joining the ENLAROhMENT of thk Facial Nerve. 1. Facial nerve. 2. Large superficial petrosal. 3. Small superficial petrosal from Jacobson's nerve. i. External superficial petrosal. 5. Chorda tympaui of the facial. 144 DISSECTION OF THE HEAD. * Union with the auditory nerve. In the bottom of the meatus the facial and auditory nerves are connected by one or two minute fihiments. * Connecting branches of the gangliform. enlargement. The swelling of the facial nerve receives three small twigs. One in front is the large superficial petrosal nerve^ (vidian) ; another is the small superficial petro- sal^ of the tympanic nerve ; and the third is the external superficial petrosal, *, which is derived from the sympathetic on the middle menin- geal artery. * The branch of the stapedius muscle arises at the back of the tympa- num, and reaches its muscle by a special canal. Chorda tympani. This long but slender branch of the facial nerve crosses the tympanum, and ends in the tongue. Arising about a quarter of an inch from the stylo-mastoid foramen (fig. 35, ^), it enters the tym- panum below tlie pyramid. In the cavity the nerve is directed forwards across the handle of the malleus and tlie membrana tympani to the Glase- rian fissure, or to an aperture on the inner side, through which it leaves the tympanum. As it issues from the cavity it emits a small branch to the laxator tympani muscle (?). Outside the skull the chorda tympani joins the gustatory nerve, and continues along it to the submaxillary ganglion and the tongue (p. 102). The AUDITORY NERVE will be learnt with the ear. Entering the audi- tory meatus with the facial it divides into two parts, of whicli one belongs to the cochlea, and the other to the vestibule. Otic ganglion (fig. 36). At this stage of the dissection there is little to be seen of the ganglion, but the student should remember that it is one of the things to be examined in a fresh part. Its situation is on the inner aspect of the inferior maxillary nerve, close to the base of the skull, and it must therefore be arrived at from the inner side. Dissection. Putting the part in the same position as for the examina- tion of Meckel's ganglion, the dissector should define the Eustachian tube and the muscles of the palate, and then take away the levator palati and that tube, using much care in removing the last. When some loose areolar tissue has been cleared away the internal pterygoid muscle (6) comes into view, with the trunk of the inferior maxillary nerve above it ; and a branch (internal pterygoid, *) descending from that nerve to the muscle. If the nerve to the pterygoid be taken as a guide, it will lead to the ganglion. To comjjlete the dissection, saAv vertically through the petrous part of the tem[)oral bone, near the inner wall of the tympanum, the bone being supported whilst it is divided. Taking off some membrane which covers the ganglion, the student may follow backwards a small branch to the tensor tympani muscle ; but he must open the small tube that contains the muscle, by entering it below tlirough tlie carotid canal. Above this small branch there is said to be another minute nerve (small superficial petrosal), which issues from the skull, and joins the back of the ganglion. A small twig is to be sought from the front of the ganglion to the tensor palati muscle ; and one, near the same spot, to join the sympathetic nerve on the middle meningeal artery. The otic ganglion (gang, auriculare, Arnold) (fig. 3G) is a small reddish body, which is situate on the inner surface of the inferior maxil- lary nerve close to the skull, and surrounds the origin of the nerve to the internal ))terygoid muscle. By its inner surface the ganglion is in contact with the Eustachian tube, and at a little distance, behind, lies the middle OTIC GANGLION. 145 meningeal artery. In this ganglion, as in the others connected with the fifth nerve, filaments from motor, sensory, and sympathetic nerves are blended. Some twigs are furnished by it to muscles. Connecting branches — roots. The ganglion is joined by a fasciculus from the motor part of the inferior maxillary nerve, and is closely united with n. Tensor tympani muscle. b. Internal pterygoid muscle with its nerve entering it. c. External carotid artery with the sym- pathetic on it. 1. Otic ganglion. 2. Branch of Jacobson's nerve. 8. Nerve to tensor tympani. 4. Chorda tympani joining gustatory. 5. Nerve to pterygoideus internus. 6. Nerve of tensor palati. 7. Auriculo-temporal nerve. Inner View of the Otic Ganglion. the branch of that nerve to the internal pterygoid muscle, thus receiving two of its roots, motor and sensory, from the fifth nerve. Its connection with the sympathetic is established by a twig from the plexus on the middle meningeal artery.^ Branches to muscles. Two muscles receive their nerves from the otic ganglion, viz., tensor tympani and circumfiexus palati. The nerve to the tensor tympani^ '', is directed backwards, and enters the bony canal con- taining that muscle. The branch for the circumjiexus, ^ arising from the front of the ganglion, may be supposed to be derived from the internal pterygoid nerve. The nerve of the internal pterygoid mnscle, ^, arises from the inner side of the inferior maxillary nerve near the skull and penetrates the deep surface of the muscle. This branch is joined by a fasciculus from thcT motor root of the fifth nerve. Directions. The remainder of the pterygo-maxillary region of the left side may be noAv examined. I Further, the ganglion is said to be connected with the tympanic nerve (of the glosso-pliarjngeal) by means of the small superficial petrosal nerve, 2, joining the posterior part. 10 146 DISSECTION OF THE TONGUE, Section XV. DISSECTION OF THE TONGUE. Directions. The tongue and larynx are to remain connected with each other whilst the student learns the general form and structure of the tongue. Dissection. The ends of the extrinsic lingual muscles that have been detached on the right side may be shortened, but enough of each should be left to trace it afterwards into the substance of the tongue. The TONGUE occupies the floor of the mouth, and is rather flattened, with the larger end turned backwards. It is free over the greater part of the surface; but at the hinder part, and at the posterior two-thirds of the under surface, it gives attachment to the muscles and the mucous mem- brane which fix it to the parts around. The tip of the tongue (apex) touches the incisor teeth ; and the base, which looks towards the pharynx, is attached to the hyoid bone, and is connected likewise with the epiglottis by three folds of mucous membrane — a central and two lateral. The upper surface of dorsum is somewhat convex, and is received into the hollow of the roof of the mouth ; along the anterior two-thirds it is divided into two equal parts by a median groove, whicli ends behind in a hollow named foramen ciecum. Tliis surface is covered with papilhe over the anterior two-thirds; but is smoother at the posterior third, though even here the surface is irregular in consequence of projecting mucous glands and follicles. The under surface, free only in part, gives attach- ment to the mucous membrane, and to the different lingual muscles con- nected with the hyoid bone and the jaw ; and in front of those muscles is a fold of the mucous membrane named fra^num linguae. The borders of the tongue are thick and round at the base of the organ, where they are marked by vertical ridges and furrows ; but gradually be- come thinner near the tip. Papillce. On the dorsum of the tongue are the following kinds of pa- pillae; the conical and filiform, the fungiform, and tlie circumvallate. The cojiical and filiform pajHllae are the numerous small jn-ojections, like the villi on the mucous membrane of the small intestine, wliich cover the anterior two-thirds of the dorsum of the tongue. Some of the papilla? (conical) are wider at their attached than at their free ends, and these are most developed over the central part of the tongue. Others become longer (filiform), especially towards the sides of the tongue. These ])apilla3 are furnished with minuter papilla;, and are provided at the tip with hair-like processes of the epithelium. Towards their limit behind, as well as on the side of the tongue, they have a linear arrangement. T\\G fungiform j)apilla.' are less numerous but larger than the preceding set, amongst which tliey are scattered. They are wider at the free end than at the part fixed to the tongue, and project beyond the other set ; they are situate mostly at the tip and sides of the tongue. They are covered witli small simple papilhi). The circumvallate or caliciform are fewer in number and larger tlian the others, and are placed at the junction of the two anterior with the STRUCTURE OF THE TONGUE. 147 posterior third of the tongue : tlieir number varies from eight to ten These papillae extend across the tongue in a line resembling the letter V with the point turned backwards. Each papilla consists of a central truncated part of a conical form, which is surrounded by a fold of the mucous membrane ; its wider part or base projects above the surface, whilst the apex is attached to tlie tongue. Both the papilla and the sur- rounding fold are furnished with smaller secondary papillae. Minute simple papilhe exist behind the c^lciform kind, and on the under surface of the free portion of the tongue ; but they are not observed till the epithelium is removed. Taste buds. Around the circum vallate papilla? is a circle of small peculiar bodies, which are covered by the epithelium : they are like a small carafe in shape, the base resting on the corium. They are formed of elongated epithelium-like cells, of which the central, resembling olfac- torial cells, are supposed to be connected with the nerve of taste. A small collection of similar bodies occupies tlie back of the tongue, on each side, just in front of the anterior pillar of the fauces. Structure of the PapillcB. The simple papillte are constructed like those of the skin, viz. of a projecting cone of membrane, which is covered by epithelium, and filled with a loop of capillaries, and a nerve. The other compound forms of the papillae may be said to be produced by outgrowths from the simple kind. Thus smaller papillary eminences spring from the common cone of limiting membrane ; and each has its separate investment of epithelium, by which the brush-like appearance on the surface is pi-oduced. From the plexus of capillary vessels in the in- terior of the papilla a looped offset is furnished to each smaller papillary projection. The entering nerve sends offsets to the different subdivisions of the papilla, on some of which end-bulbs may be recognized. Structure. The tongue consists of two symmetrical halves separated by a fibrous layer in the middle line. Each half is made up of muscular fibres with interspersed fat ; and entering it are the lingual vessels and nerves. The whole tongue is enveloped by the mucous membrane ; and a special fibrous membrane attaches it to the hyoid bone. Dissection. To define the septum, and the membrane attaching the tongue to the hyoid bone, the tongue is to be placed on its dorsum ; and, the remains of the right mylo- and genio-hyoideus having been removed, the genio-hyo-glossi muscles are to be cleaned, and drawn from one another along the middle line. After separating those muscles, except for an inch in front, and cutting across tlieir intercommunicating fibres, the edge of the septum will appear. By tracing the hinder fibres of the genio-hyo- glossus muscle towards the os hyoides, the hyo-glossal membrane will be arrived at. Outside this triangular muscle in the middle line, is the longitudinal bundle of the inferior lingualis, which will be better seen subsequently. Fibrous tissue. Along the middle line of the tongue is placed a thin lamina of this tissue, forming a septum : its root is attached by another fibrous structure, the hyo-glossal membrane ; and covering the greatiir part of the organ is a submucous layer of the same tissue. Septum. This structure forms a vertical partition between the two halves of the tongue (fig. 37, ^), and extends from the base to the apex. It is thicker posteriorly than anteriorly, and is connected behind with the hyo-glossal membrane. To each side the transverse muscle is connected. Its disposition may be better seen subsequently on a vertical section. In 148 DISSECTION OF THE TONGUE. some instances a small fibro-cartilage, about a quarter of an inch deep and lonjr, exists in the septum. The hyo-glossal membrane is a thin but strong fibrous lamina, which attaches the root of the tongue to the upper border of the body of the hyoid bone. On its under or anterior surface some of the hinder fibres of the genio-hyo-glossi are inserted, as if this was their aponeuroses to attach tliem to the os hyoides. The submucous Jibrous or aponeurotic stratum of the tongue invests the organ, and is continued into the sheaths of the muscles. Over the pos- terior third of the dorsum its strength is greater than elsewhere; and in front of the epiglottis it forms bands in the folds of the mucous membrane in that situation. Into it are inserted the muscular fibres which end on the surface of the tongue. Muscles. Each half of the tongue is made up of extrinsic and in- trinsic muscles. The former or external are distinguished by having only their termination in the tongue ; and the latter or internal, by having both origin and insertion within the origin — that is to say, springing from one part and ending in another. The extrinsic muscles (fig. 37) are the following : palato and stylo- glossus, hyo and genio-hyo-glossus, and pharyngeo-glossus. Only the lingual endings of these are now to be looked to. Dissection. After the tongue has been firmly fastened on its left side, the extrinsic muscles may be dissected on the right half. Three of these muscles, viz., palato-, d, stylo-, b, and hyo-glossus, c, come together to the side of the tongue, at the junction of the middle and posterior third ; and, to follow their radiating fibres forwards, it will be necessary to remove from the dorsum, between them and the tip, a thin layer consisting of the mu- cous membrane and fleshy fibres of the upper lingualis. Beneath the tip a junction between the stylo-glossus muscles of opposite sides is to be traced. The part of the constrictor muscle, g, which is attached to the tongue, and the ending of the genio-hyo-glossus, will come into view on the divi- sion of the hyo-glossus. Only the two parts of the hyo-glossus (basio- and cerato-glossus, p. 99), which arise from the body and great wing of the hyoid bone, are referred to above. To lay bare the third part, or the chondro-glossus, f, which is a small muscular slip attached to the small cornu of tlie os hyoides, turn upwards the dorsum of the tongue, and feel for the small cornu of the hyoid bone through the mucous membrane. Then remove the mucous membrane in front of the cornu, and the fibres of the muscle radiating forwards will be exposed. The palato and stylo-glossus muscles, D and b, are partly combined at their attachment to the lateral part of the tongue, and form, together with tiie following muscle, an expansion over the anterior two-thirds of the dorsum beneath the superficial lingualis. In this stratum tiie fibres radi- ate irom the point of contact of the muscles with the tongue — some passing almost horizontally inwards to the middle, and others obliquely forwards to the tip of the organ. A' great portion of the stylo-glossus is directed along the side of the tongue ; and some fibres are inclined to the under surface in front of the hyo-glossus, to join those of tlie opposite muscle beneath the tip. Hyo-glossvs. The two superficial parts of the muscle (basio and cerato- MUSCLES OF THE TONGUE. 149 Fig: glossus, c, p. 99) enter the under surface of the tongue, between the stylo-glossus and the lingualis. After entering that surface by separate bundles, they are bent round the margin, and form, with the two preceding muscles, a stratum on the dorsum of the tongue. The third part of the muscle, or the chondro- glossus, F, is distinct from the rest. About two or three lines wide at its origin from the root of the small cornu, and from part of the body of the os hyoides, tlie muscle entering beneath the upper lingualis, passes obliquely inwards over the posterior third of the dorsum, to blend with the hyo glossus. Cortex of the tongue. The muscles above described, together with the superficial lingua- lis, constitute a cortical layer of oblique and longitudinal fibres, which covers the tongue, except below where some muscles are placed, and resembles "a slipper turned upside down." This stratum is pierced by deeper fibres. The genio-hyo-glossus (fig. 38, ^) enters the tongue vertically on the side of the septum, and perforates the cortical covering to end in the submucous tissue. In the tongue the fibres spread like the rays of a fan from apex to base, and are collected into bundles as they pass through the transversalis. The most [)OS- terior fibres end on the hyo-glossal membrane and the hyoid bone ; and a slip is prolonged from them, beneath the hyo-glossus, to the up- per constrictor of the pharynx. A vertical section at a future stage will siiow tlie radiation of its fibres. The pharyngeo-glossiis (glosso-pharyngaus), or the part of the upper constrictor attaclied to the side of the tongue, passes amongst fibres of the hyo- glossus, and is continued with the trans- verse muscle to the septum. The intrinsic nmscles (fig. 38) are three in number in each half of the tongue, viz., transversalis, with a superior and an infe- rior lingualis. Dissection. To complete the prepara- tion of the inferior lingualis on the right side, the fibres of the stylo-glossus covering it in front, and those of the genio-hyo- glossus over it behind, are to be cut through. The superior lingualis (fig. 37, ^) may be shown, on the left side, by taking the thin mucous membrane from tlie ui)per surface from tip to base. The transversalis (fig. 38, ^) may be laid bare on the right side, by cutting away on the upper surface the stratum of the extrinsic muscles Muscles on the surface of THE ToXdUE. A. Superficial lingualis. B. Stylo-glossus. c Hyo-glossus. D. Palato-glossus. F. Chondro-glossus. o. Phaiyngeo-glossus. H. Septum liuguaj (Zaglas). Fig. 38. Intrinsic Muscles of the Tongue. A. Geuio-hyo-glossu8. B. Septum linguffl. c. Traasversalis. D. Inferior lingualis (Zaglas). 150 DlSSECTrON OF THE TONGUE. already seen ; and by removing on the lower surface, the inferior lingualis and the genio-hyo-glossus. The nerves of the tongue are to be dissected on the left half as well as the part will admit ; but a recent specimen would be required to follow them satisfactorily. The transversalis muscle (fig. 38, ^) forms a horizontal layer in the substance of the tongue from base to apex. The fibres are attached in- ternally to the side of the septum, and are directed thence outwards, the posterior being somewhat curved, to their insertion into the side of the tongue. Its fibres are collected into vertical plates, so as to allow the passage between them of the ascending fibres of the genio-hyo-glossus. Action. By the contraction of the fibres of these muscles the tongue is made narrower and rounder, and is increased in length. The superior lingualis (fig. 37, ^, noto-glossus of Zaglas) is a very thin layer of oblique and longitudinal fibres close beneath the submucous tissue on the dorsum of the tongue. Its fibres arise from the fraenum ej)iglotti- dis, and from the fascia along the middle line ; from this attachment they are directed obliquely outwards, the anterior becoming longitudinal, to the margin of the tongue, at which they end in the fascia. Action. Both muscles tend to shorten the tongue ; and they will bend the point back and up. The inferior lingualis (fig. 38, ^) is much stronger than the preceding, and is placed under the tongue, between the hyo and genio-hyo-glossus. The muscle arises posteriorly from the fascia at the root of the tongue ; and the fibres are collected into a roundish bundle: from its attached sur- face fasciculi are continued vertically through the transverse fibres up- wards to the dorsum; and at the anterior tliird of the tongue, where the muscle is overlaid by the stylo-glossus, some of the fibres are applied to that muscle and distributed with it. Action. Like the upper lingualis this muscle shortens the tongue, and bends the point down and back. The mucous membrane is a continuation of that lining the mouth, and is provided with a laminar epithelium. It partly invests the tongue, and is reflected off at different points in the form of folds (p. 1.46). At the epiglottis are three small glosso-epiglottid folds, connecting tiiis body to the root of the tongue ; the central one of these is called the fra^num of the epiglottis. Like the membrane of the moutli, it is furnished with numerous glands, and some follicles. The follicles are depressions of the mucous membrane, which are sur- rounded by closed capsules in the submucous tissue, like the arrangement in the tonsil: they occupy the dorsum of the tongue between the papillne circumvallaia3 and the epiglottis, where they form a stratum, close beneath the mucous membrane. The glands (lingual) are racemose or compound in structure, similar to those of tlie lips and cheek, and are placed beneath tlie mucous membrane on the dorsum of the tongue behind the papilhe vallatie. A few are found in front of the circumvallate papillae, where they project into the muscular substance. Some of their ducts open on the surface; others into the hol- lows around the large [)apill*!, or into the foramen Ciccum and the depres- sions of the follicles. Opposite the papilhe vallatae, at the margin of the tongue, is a small cluster of submucous glands. Under the tip of the tongue, on each side EXTERNAL LARYNGEAL MUSCLES. 151 of the fi'cTinum, is another elongated collection of the same kind of glands imbedded in the muscular fibres, from which several ducts issue. Nerves. There are three nerves on the under part of each half of the tongue, viz., the gustatory, the hypoglossal, and the glosso- pharyngeal (fig. 23). The gustatory nerve gives upwards filaments to the muscular substance, and to the two smallest sets of papilla?, conical and fungiform ; it joins also the hypoglossal nerve. The hypoglossal nerve is spent in long slender offsets to the muscular substance of the tongue. The glosso-pharyngeal nerve divides under the hyo-glossus into two branches: — One turns to the dorsum, and ramifies in the mucous mem- brane behind the foramen cjecum. The other passes beneath the side of the tongue, and ends in branches for the muscular substance; it supplies the papillae circumvallatse, as well as the mucous membrane covering the lateral part of the tongue. Vessels. The arteries are derived chiefly from the lingual of each side; these, together w^ith the veins, have been examined (p. 101.) Section XVI. DISSECTION OP THE LARYNX. The larynx is the upper dilated part of the air tube, in which the voice is produced. It is constructed of several cartilages united together by ligamentous bands ; of muscles for the movement of the cartilages ; and of vessels and nerves. The whole is lined by mucous membrane. Dissection. The tongue may be removed from the larynx by cutting through its root, but this is to be done without injuring the epiglottis. If the student learns the laryngeal cartilages before he begins the dis- section of the larynx, he will obtain more knowledge from the study of this Section. Occupying the middle line of the neck, the larynx is placed in front of the pharynx, and between the carotid vessels. It is pyramidal in form. The base is turned upwards, and is attached to the hyoid bone ; and the apex is continuous with the trachea. In length it measures about one inch and a half; in width at the top one inch and a quarter, and at the lower end one inch. The front is prominent along the middle line of the neck; and the pos- terior surface is covered by the mucous membrane of the pharynx. The larynx is very movable, and during deglutition is elevated and depressed by the different extrinsic muscles. Muscles. Commonly five pair and one single muscle are described in the larynx. Three are outside the cartilages, and three are more or less concealed by the thyroid cartilage. Directions. On one side of the larynx, say the right, the muscles may be dissected, and on the opposite side the nerves and vessels ; and those superficial muscles are to be first learnt, which do not require the carti- lages to be cut. Dissection. The larynx being extended and fastened with pins, the dissector may clear away from tlie os hyoides and the thyroid cartilage the 152 DISSECTION OF THE LARYNX following extrinsic muscles, viz., constrictor, sterno-liyoid, sterno-thyroid, and thyro-hyoid. In front, between the thyroid and cricoid cartilages, one of the three small external muscles — crico-thyroid (fig. 39), will be recognized. The other two external muscles (fig. 40) are situate at the posterior aspect of the larynx: to denude them it will be necessary to turn over the larynx, and to remove the mucous membrane covering it. On the back of the circoid cartilage the dissector will find the crico-arytajnoideus posti- cus muscle; and above it, on the posterior part of the arytaenoid cartilages, the arytaenoid muscle will appear. The CRico-THYROiDEL'S MUSCLE (fig. 39, ^) is triangular in form, and is separated by an interval from the one on the opposite side. It arises from the front and the lateral part of the cricoid cartilage ; and its fibres Fig. 39. Fiff. 40. Front View of the Larynx. 1. Crico-thyroid muscle 2. Thyroid cartilai(e. 3. Cricoid cartilage. Hinder View of the Lartn.x. A. Superficial part of the arytsenoideus muscle. B. Deep part of the arytacnoideus. 0. Crico-arytseuoideus posticus. ascend to be inserted into the lower cornu, and the low'er border of the thyroid cartilage as far forwards as a quarter of an inch from the middle line ; also, for a short distance (a line), into the inner surface of that carti- lage. The muscle rests on the crico-thyroid membrane, and is concealed by the sterno-thyroid muscle. Action. It approaches the thyroid to the cricoid cartilage, making longer the distance between the thyroid and the arytaenoid cartilages, and tightens indirectly the vocal cords. The CKico-ARYTiENOiDEUS POSTICUS MUSCLE (fig. 40, ^) lics on the posterior part of the cricoid cartilage. Its origin is from the depression on the side of the vertical ridge at the back of that cartilage. From this origin the fibres are directed outwards, and are inserted into a projection at tlie outer part of the base at the arytaiuoid cartilage. INTERNAL LARYNGEAL MUSCLES. 153 Action. It rotates the aiyta^noid cartilage, turning out the lateral pro- jection at the base, and enlarges the interval between the cartilages. At the same time the upper orifice of the larynx is widened by the separation from each other of its lateral boundaries. Musciilus kerato-cricoideus (Merkel). This is a small fleshy slip which is occasionally seen below and close to the precedingmuscle ; it arises from the cricoid cartilage, and is inserted into the back part of the lower cornu of the thyroid cartilage. The ARYT^NOiDEUS is a single muscle in the middle line (fig. 40, ^), and is placed on the posterior surface of the aryt^enoid cartilages : it pos- sesses two sets of fibres, superficial and deep, with different directions. The deep fibres, b, are transverse, and are inserted into the outer border and the posterior surface of each cartilage ; they close the interval between the cartilages. The superficial fibres, a, consist of two oblique fasciculi, which cross like the parts of the letter X, each passing from the base of one cartilage to the apex of the other : a few of these fibres are continued beyond the cartilage to join the thyro-arytajnoid muscle, and the depressor of the epiglottis. Action, The muscle causes the arytainoid cartilages to glide towards one another, and diminishes much, or closes the rima glottidis. Acting with the depressors of the epiglottis it will assist in closing the upper orifice of the larynx. Dissection. The remaining muscles and the vocal apparatus would be learnt better on a fresh larynx, if this can be obtained. To bring into view the muscles, which are concealed by the thyroid cartilage (fig. 41) it will be necessary to remove the right half of the cartilage, by cutting through it a (piarter of an inch from the middle line, after its lower cornu has been detached from the cricoid. By dividing next the crico-thyroid membrane attached to the lower edge, and the thyro-hyoid ligament con- nected with the upper margin, the loose piece will come away on separat- ing it from the subjacent areolar tissue. By the removal of some areolar tissue, the dissector will define inferiorly the crico-arytjcnoid muscle ; above it, the thyro-arytienoideus muscle ; and still higher, the thin muscular fibres (depressor of the epiglottis) in the fold of mucous membrane between the epiglottis and the aryta^noid cartilage. On cleaning the fibres of the thyro-arytjenoideus near the front of the larynx, the top of the sacculus laryngis with its small glands will appear above the fleshy-fibres. The CRico AKYT.ENOiDEUS LATERALIS (fig. 41,^) is a Small lengthened band, which arises from the upper border of the cricoid cartilage at the lateral part ; its fibres are directed backwards to be inserted into a })rojec- tion on the outer side of the base of the arytaenoid cartilage, and into the contiguous part of the outer surface. This muscle is concealed by the crico-thyroideus, and its upper border is contiguous to the succeeding muscle. Action. Rotating the aryta^noid cartilage by moving inwards the pro- jection on the outer part of the base, it replaces the cartilage after tliis has been everted by the crico-aryta^noideus posticus. It may also approach the one vocal cord to tlie other, and so narrow the glottis. The THYRO-ARYTyENOiDEUs MUSCLE (fig. 41) extends from the thyroid to the arytcBnoid cartilage ; it is thick below, but thin and expanded above. The muscle arises from the thyroid cartilage near the middle line, for about the lower half of the deptli, and from the crico-thyroid ligament. The fibres are directed backwards with different inclinations : — The external, *, 154 DISSECTION OF THE LARYNX Fig. 41. ascend somewhat, and are inserted in- to the u{)per part of" the outer surface of the arytaenoid cartilage, and blend with the depressor of the epiglottis. The internal and lower fibres, ^, are transverse, and form a thick bundle, which is inserted into the fore part of the base of that cartilage, and into the outer surface. By its outer surface the muscle is in contact with the thyroid cartilage ; and the inner surface rests on the vocal cords, and on the ventricle of the larynx and the pouch. Action. It moves forwards the ary- taenoid cartilage towards the thyroid, and relaxes the vocal cord. By a thin band of fibres along the upper edge the rima glottidis can be narrowed, and the cord put into the vocalizing position. The DEPRESSOR OB' THE EPIGLOT- TIS (fig. 41, ^) (thyro-arytseno-epiglot- tideus) is a thin muscular layer by the side of the upper opening of the larynx. Its fibres arise posteriorly from the front of the arytaenoid cartilage, some being continuous below with fibres of the arytiianoid and thyro-aryta^noid muscles ; and anteriorly by a narrow slip from the thyroid cartilage near the middle line. From those attachments the fibres turn upAvards with very dif- ferent directions, and are inserted into the border of the epiglottis on the same side. The strengtii of the muscle va- ries much in diflferent bodies. Some of the lower fibres of the muscle, which cover the top of the laryngeal pouch, have been described by Mr. Hilton as a separate muscle with the name arytceno-epiglottideus inferior. Action. By the contraction of the fibres, the tip of the arytaenoid car- tilage will be moved forwards and inwards, and the eppiglottis will be lowered over the orifice of the larynx. The fibres of the muscle which are s})read over the sacculus will compress it, and assist in the expulsion of the contents. Parts inside the larynx. The |)arts more immediately concerned in the production of the voice are, the vocal cords, the glottis, and the ventricle of the larynx and its pouch : these are placed within, and are protected by the laryngeal cartilages. Dissection. For the purpose of displaying the vocal apparatus, let the tube of the larynx be divided along the posterior i)ai't, as in fig. 42 ; and in cutting through the arytitnoid muscle, let the incision be rather to the right of the middle line, so as to avoid the nerves entering it. On looking into the larynx a hollow (ventricle) will appear on each View op the Internal Mpsci-es of the Larynx. 1. Crico-thyroidens detached. 2. Crico-arytierioideiis p )8ticu8. 3. Crico arytaeaoideus lateralis. 4. Thyro-arytsenoideus, superficial part. a. Depressor of tlie epiglottis. 6. Thyro-hyoideus, cut 8. Deep or transverse part of thyro-arytae noideus. GLOTTIS AND LARYNGEAL POUCH. 155 side ; and bounding the ventricle above and below are the whitisli bands of the vocal cords. If a probe be passed into that hollow, it will enter a small pouch (sac- culus laryngis) by an aperture in the anterior and upper part. The dis- sector should fill the sacculus on the left side by introducing a small piece of cotton wool into it. The laryngeal space reaches from the epiglottis to the lower border of the cricoid cartilage. It opens above into the pharynx, and below into the trachea ; and in the intermediate portion are lodged the parts pro- ducing voice. The upper orifice of the larynx (fig. 29, ^) will be evident on placing in contact the cut surfaces. It is triangular in shape, with the base in front and the apex behind, and its sides are sloped obliquely downwards in the antero-posterior direction. Its boundaries are, — the epiglottis in front, the aryta3noid muscle and cartilages behind, and the arytieno-epiglottidean fold of mucous membrane on each side. This aperture is closed by the epiglottis during deglutition. The lower opening^ limited by the inferior edge of the cricoid cartilage, is circular in form, and is of the same size as that cartilage. The laryngeal cavity is much reduced in size within the thyroid car- tilage by the vocal cords, and is dilated above and below them for the pur- pose of allowing their free vibration. The lower dilatation may be seen to be as large as the ring of the cricoid ; and the upper, much smaller, corresponds with the ventricle of the larynx. Above the upper bulge the wall of the larynx slants up to the epiglottis. The glottis or rima. glottidis^ is the interval between the lower vocal cords (fig. 44) ; it is })laced on a level with the base of the arytsenoid car- tilages, and is the narrowest part of the laryngeal cavity. Its sides are constructed partly of ligament and partly of cartilage : — thus, for about the two anterior thirds is the elastic vocal cord (fig. 42, ^), whilst at the posterior third is the smooth inner surface of the arytasnoid cartilage, e. Behind it is bounded by the arytnsnoid muscle ; and in front by the thyroid cartilage and the attachments of the vocal cords. The size of the interval differs in the two sexes. In the male it mea- sures from before back nearly an inch (less a line), and across at the base, when dilated, about a third of the other measurement. In the female the dimensions will be less by two or three lines. Alterations in the size and form affect the interval where it is bounded by the cartilages, as well as where it is limited by the ligaments. In the former part, the clianges are occasioned by the movements of the arytas- noid cartilages ; but in the latter they are due to the lengthening and shortening of the bands. In the state of rest it is a narrow fissure which is enlarged a little behind and rounded; but when dilated it is triangular in form, like the upper orifice, though its wider part is turned backwards to the aryta^ioid muscle. In the living body the fissure is larger in inspiration than in exi)iration. The mus- cles too are constantly producing alterations in the fissure, some acting more immediately on the cartilages as dilators and contractors of the base; and others altering the state of the ligaments, by elongating and shortening the sides. The base is enlarged, and the interval rendered triangular by the poste- rior crico-arytienoid ; and is diminished by the arytienoid, and the lateral crico-aryta3noid. And the ligamentous sides are elongated and made tense by the crico-thyroidei, but are shortened by the thyro-arytienoidei. 156 DISSECTION OF THE LARYNX The ventricle of the larynx (fig. 42, ^) is best seen on the left side. It is the oval hollow between the vocal cords, whose upper margin is semi- lunar, and the lower straight. It is lined by the mucous membrane, and on the outer surface are the fibres of the thyro-aryt:enoid muscle. In the anterior part is the aperture into the laryngeal pouch. The laryngeal pouch (sacculus laryngis) (fig. 42,^), has been laid bare in part on the right side by the removal of the half of the thyroid cartilage (p. 153), but it will be seen again in the subsequent dissection for the vocal cords. It is a small membranous sac, half an inch deep and cylindrical in form, which projects upwards between the upper vocal cord and the thyroid slip of the depressor of the epiglottis, and reaches sometimes as high as the upper border of the thyroid cartilage. Its cavity communicates with the front of the ventricle by a somewhat narrow aperture. On the outer sur- face are numerous small glands, whose ducts are transmitted through tile coats of the sac to the inside. Numerous nerves are distributed over the top. Its upper part is covered by the muscular slip before referred to. Dissection. The general shape and position of the vocal cords are evi- dent on tlie left half of the laryngeal tube, but to show more fully the na- ture of the lower cord, put the cut surfaces in contact, and detach on the right side the crico-arytajnoideus lat- eralis from its cartilages. Remove in like manner the thyro-arytognoi- deus, raising it from beibre back. By the removal of the last muscle, a fibrous membrane, crico-thyroid (fig. 44, ^), comes into view, and its up- per free edge will be perceived to constitute the inferior or true vocal cord. Whilst taking away the thyro- arytienoideus, the ventricle and the sacculus laryngis, which are formed chiefiy by mucous membrane, will disappear. The vocal cords or the thyro-ary- tcenoid ligaments (fig. 42), are two bands on each side, which are ex- tended from the angle of the thyroid to the aryti«noid cartilage — one ibrm- ing the u|)per, the other the lower margin of the ventricle. The upper ligament (false vocal cord (fig. 42, ^) is semilunar in form, and is much weaker than the other. It is fixed in front to the angle of the thyroid cartilage, near the attachment of the epiglottis ; and behind to Vocal Apparatus, o\ a Vertical Section OF THE Larynx. A. Ventricle of the larynx. B. True vocal cord, c. False vocal cord. D. Sacculus laryugif. E Arytaenoid cartilage. F. Cricoid cartilage. G, Thyroid cartilage. H. Epiglottis. K. Crico-thynnd ligament. L. Thyro-hyoid ligament. GLOTTIS AND LARYNGEAL POUCH. 157 the outer surface of the aryta^noid cartilage. This ligament consists chiefly of white fibrous tissue, whicli is continuous with that in the arytteno-epi- glottidean fold of mucous membrane. The inferior ligament (chorda vocalis, fig. 42, ^) is attached in front to the angle of the thyroid cartilage, about half-way down below the notch ; the ligament is directed backwards, and is inserted into the anterior promi- nence at the base of the arytienoid cartilage. It is about seven lines long in man, and two less in the woman. Internally this band is covered by thin mucous membrane, and projects towards its fellow into the cavity of the larynx, the interval between it and the opposite one being the glottis. Externally it is connected with the thyro-aryttenoid muscle And infe- riorly it is continuous with the crico-thyroid ligament, k. The edge that bounds the ventricle is straight and well defined, and vibrates to produce sounds. The ligament is composed of fine elastic tissue. The mucous membrane of the larynx is continued from that investing the pharynx, and is prolonged to the lungs through the trachea. When entering the larynx it is stretched between the epiglottis and the tip of the arytenoid cartilage, forming the arytaeno-epiglottid fold on each side of the laryngeal orifice: at this spot it is very loose, and the submucous tissue abundant. In the larynx the membrane lines closely the cavity, sinks into the ventricle, and is prolonged into the laryngeal pouch. On the thyro-arytenoid ligaments it is very thin and adherent, allowing these to be visible through it. In the small part of the larynx above the vocal cords, the epithelium is of the laminar kind, and free from cilia. But a columnar ciliated epithe- lium covers the surface below the level of the superior cords, though it becomes flattened without cilia on the cords : on the epiglottis it is ciliated in the lower half. Numerous branched glands are connected with the mucous membrane of the larynx, and the orifices will be seen on the surface, especially at the posterior aspect of the epiglottis. In the edge of the arytieno-epiglot- tidean fold there is a little swelling occasioned by a mass of subjacent glands (arytJEUoid) ; and along the upper vocal cord lies another set. None exist over the vocal cords, but close to those bands is the collection of the sacculus laryngis, which lubricates the ventricle and the lower vocal cord. Dissection of nerves and vessels. The termination of the laryngeal nerves may be dissected on the untouched side of the larynx. For this purpose the other half of the thyroid is to be disarticulated from the cri- coid cartilage, care being taken of the recurrent nerve, which lies near the joint between the two. The trachea and larynx should be fastened down next with pins; and after the thyroid has been drawn away from the cricoid cartilage, the inferior laryngeal nerve can be traced over the side of the latter cartilage to the muscles of the larynx, and mucous mem- brane of the pharynx. Afterwards the superior laryngeal is to be found as it pierces the thyro- hyoid membrane, and branches of it are to be followed to the mucous membrane of the larynx and pharynx. Two communications are to be looked for between the laryngeal nerves ; one is b(meath the thyroid car- tilage, the other in the mucous membrane of the pharynx. An artery accompanies each nerve, and its offsets are to be dissected at the same time as the nerve. 158 DISSECTION OF THE LARYNX. Nerves. The nerves of the larynx are the superior and inferior hiryn- geal branches of the pneumo-gastric (p. 113); the former is distributed to the mucous membrane, and tlie latter cliiefly to the muscles. The inferior laryngeal nerve (recurrent), when about to enter the larynx, furnishes backwards an offset to the mucous membrane of the pharynx ; this joins filaments of the upper laryngeal. The nerve then passes beneath the ala of the thyroid cartilage, and ends in branches for all the special muscles of the larynx except the crico-thyroideus. Its small muscular branches are superficial, but that to the aryta^noid muscle passes beneath the crico-arytfenoideus posticus. Beneath the thyroid car- tilage the inferior is joined by a long offset of the upper laryngeal nerve. The superior laryngeal nerve pierces the thyro-hyoid ligament, and gives offsets to the mucous membrane of the pharynx ; it furnishes also a long branch beneath the ala of the thyroid cartilage to communicate with the recurrent nerve. The trunk then terminates in many branches for the supply of the mucous membrane : — Some of these ascend in the aryta3no- epiglottid fold to the epiglottis, and the root of the tongue. The others, which are the largest, descend on the inner side of the ventricular pouch, and supply the lining membrane of the larynx as low as the vocal cords. One nerve of this set pierces the arytsenoid muscle, and ends in the mucous membrane. Vessels. The arteries of the larynx are furnished from the superior and in erior thyroid branches (p. 85 and 78). The laryngeal branch of the superior thyroid artery enters the larynx with the superior laryngeal nerve, and divides into ascending and descend- ing branches ; some of these enter tlie muscles, but the rest supply the epiglottis, and the mucous membrane from the root of the tongue to the chorda vocalis. Like the nerves, it unites with the following artery both beneath the ala of the thyroid cartilage, and in the mucous membrane of the pharynx. The laryngeal branch of the inferior thyroid artery ascends on the back of the cricoid cartilage, and ends in the mucous membrane of the pharynx and the postei-ior muscles of the larynx. Some other twigs from the superior thyroid artery perforate the crico- thyroid membrane, and ramify in the mucous lining of the interior of the larynx at the lower part. Laryngeal veins. The vein accompanying the branch of the superior thyroid artery, joins the internal jugular or the superior thyroid vein ; and the vein with the artery from the inferior thyroid opens into the plexus of the inferior thyroid veins (p. 85 and 78). Section XVII. HYOID BONE, CARTILAGES AND LIGAMENTS OF THE LARYNX, AND STRUCTURE OF THE TRACHEA. Dissection. All the muscles and the mucous membrane are to be taken away so as to denude the hyoid bone, the cartilages of tlie larynx, and the epiglottis ; but the piece of membrane that joins the hyoid bone CARTILAGES OF LARYNX. 159 to the thyroid cartilage, and the ligaments uniting one cartilage to another on the left side, should not be destroyed. In the arytieno-epiglottidean fold of mucous membrane, a small carti- laginous body (cuneiform) may be recognized ; an oblique whitish pro- jection indicates its position. The hyoid bone (os hyoides) (fig. 43) ^'s situate between the larynx and the root of the tongue. Resembling the letter U, placed horizontally and with the legs turned backwards, it offers for examination a central part or body, and two lateral pieces or cornua on each side. The body, c, is thin and flattened, and measures most in the transverse direction. Convex in front, where it is marked by a tubercle, it presents an uneven surface for the attachment of muscles ; whilst on the opposite aspect it is concave. To the upper border the fibrous membrane (hyo- glossal) fixing the tongue is attached. The cornua are two in number on each side (large and small). The large cornu, h, continues the bone backwards, and is joined to the body by an intervening piece of cartilage. The surfaces of this cornu look somewhat upwards and downwards ; and the size decreases from before backwards. It ends posteriorly in a tubercle. The small cornu, or ap- pendix, J, is dissected upwards from the point of union of the great cornu with the body, and is joined by the stylo-hyoid ligament : it is seldom wholly ossified. Cartilages of the Larynx (fig. 43). There are four large carti- lages in the larynx, which are concerned in the production of the voice, viz., the thyroid, the cricoid, and the two arytasnoid. In addition there are some yellow fibro-cartilaginous structures, viz., the epiglottis, a capitu- lum to each aryttenoid cartilage, and a small ovalish piece (cuneiform) in each arytoeno-epiglottidean fold of mucous membrane. The thyroid cartilage., B, is the largest of all : it forms the front of the larynx, and protects the vocal apparatus as with a shield. The upper part of the cartilage is considerably wider than the lower, and in conse- quence of this form the larynx is somewhat funnel-shaped. The anterior surface is prominent in the middle line, forming the subcutaneous swelling named pomiim Adami ; but the cartilage is concave behind at the same spot, and gives attachment to the epiglottis and the thyro-arytaenoid mus- cles and ligaments. The upper border is notched in the centre. The cartilage consists of two square halves, which are united in the middle line. Posteriorly each half of the cartilage has a thick border, which terminates upwards and downwards in a rounded process or cornu (e and f). Both cornua are bent slightly inwards: of the two, the upper, E, is the longest ; but the lower one, f, is tliicker than the other, and articulates with the cricoid cartilage. The inner surface of each half is smooth ; but the outer is marked by an oblique line for the attachment of muscles, which extends from a tubercle near the root of the upi)er cornu, almost to the middle of the lower border. The cricoid cartilage, D, is stronger though smaller than the thyroid, and encircles the cavity of the larynx ; it is partly concealed by the shield- like cartilage, below which it is placed. It is very unequal in depth be- fore and behind, — the posterior part being three times deeper than the anterior, something like a signet ring. Its hollow is about as large as the fore finger. The outer surface is rough, and gives attachment to muscles. At the back of the cartilage there is a flat and rather square portion, which is 160 DISSECTION OF THE LARYNX. Fig. 43. marked by a median ridge between two contiguous muscular depressions. On eacli side, immediately in front of the square part, is a shallow articu- lar mark, whicli receives the lower cornu of the thyroid cartilage. The inner surface is smooth, and is covered by mucous membrane. The lower border is undulating, and is united to the trachea by fibVous membrane. The upper border is nearly straight posteriorly, opposite the deep part of the ring; and this portion is limited on each side by an articular mark for the arytcenoid cartilage. In front of that spot the border is sloped obliquely downwards to the middle line. At the middle line behind there is a sliglit excavation in each border. The two arytcenoid cartilages, c, are placed one on each side at the back of the larynx, on the upper border of the cricoid cartilage. Each is pyramidal in shape, is about half an inch in depth, and offers for examination a base and apex, and three surfaces. The base has a slightly hollowed sur- face behind for articulation w^ith the cricoid cartilage, and is elongated in front into a process which gives attach- ment to tlie vocal cord. The apex is directed backwards and somewhat in- wards, and is surmounted by the carti- lage of Santorini. The inner surface is narrow, especially above, and flat. The outer is wide and irregular, and on it is a small projection at the base, wdiich receives the insertion of some of the muscles. At the pos- terior aspect tlie cartilage is concave and smooth. Cartilages of Santorini. Attached to the apex of each arytienoid cartilage is the small, conical fibro-cartilage of Santorini (corniculum ca[)itulum), which is bent inwards towards the one of the opposite side. The arytoeno-epiglottidean fold is connected with it. Cuneiform cartilages. Two other small fibro-cartilaginous bodies, one on each side, which are contained in the arytoeno-epiglottid folds, have received tliis name. Each is somewhat elongated and rounded in form, like a grain of rice; it is situate obliquely in front of tiie capitulum of the arytamoid cartilage, and its place in the fold of the mucous membrane is marked by a sliglit whitish projection. The epiglottis (fig. 43, ^) is single, and is the largest of the pieces of yellow fibro-cartilage. In form it is cordate, and it resembles a leaf, with the stalk below and the lamina or expanded part above. Its position is behind the tongue, and in front of the orifice of the larynx. During HyoiD Bonk and the Laryw«eal Cartilages. a. Body of the hyoid bone. H. Large cornu. J. Small cornu. A. Epiglottis. B. Thyroid cartilage, c. Arytenoid cartilage. D. Cricoid cartilasje. E. Upper cornu, and F. Lower cornu of the thyroid carti- lage. LIGAMENTS OF LARYNX 161 Fisr. 44. respiration it is placed vertically, but during deglutition it takes a hori- zontal direction so as to close tlie opening of the larynx. The anterior sui-face is bent forwards to the tongue, to which it is con- nected by three folds of mucous membrane ; and the posterior surface, hollowed laterally, is convex from above down. To its sides the arytseno- epiglottid folds of mucous membrane are united. After the mucous mem- brane has been removed from tlie epiglottis its substance will be seen to be perforated by numerous spaces, which lodge mucous glands. Between the epiglottis and the hyoid bone is a mass of yellowish fat with some glands; this has been sometimes called the epiglottidean gland. Ligaments of the Larynx. The larynx is connected by extrinsic ligaments with the hyoid bone above and the trachea below. Other liga- ments join together the cartilages, forming joints in some cases. Union of the larynx with the hyoid bone and the trachea. A thin loose elastic membrane (thyro-hyoid) passes from the thyroid cartilage to the hyoid bone; and a second membrane connects the cricoid cartilage with the trachea. The thyro-hyoid ligament (fig. 42, l) is at- tached on the one part to the upper border of the thyroid cartilage; and on the other, to the upper border of the hyoid bone, at the posterior aspect. Of some thickness in the centre, it gradually be- comes thinner towards the sides ; and it ends laterally in a rounded elastic cord, which inter- venes between the extremity of the hyoid bone and the upper co]"nu of the thyroid cartilage. The superior laryngeal nerve and vessels per- forate the ligament, and a synovial membrane is placed between it and the posterior surface of the hyoid bone. In the elastic lateral part of the ligament will be found occasionally a small ossific nodule (cartilago triticea). The membrane joining the lower border of the cricoid cartilage to the ilrst ring of the trachea — crico-tracheal ligament, resembles the band joining the rings of the trachea to each other. Union of the cricoid and thyroid cartilages. These cartilages are joined in the middle line in front by ligament ; and on the side, by a joint with the small cornu ot the thyroid cartilage. The crico-thyroid ligament or membrane (fig. 44, ^) closes the space between the thyroid, cri- coid, and arytaenoid cartilages, and the right half is now visible. It is yellow in color, and is formed mostly of elastic tissue. At the centre it is thick and strong, but is thinner on each side as it is continued backwards. By the lower bor- der it is fixed to the upper edge of the cricoid as far back on each side as the joint with the aryttenoid cartilage. Its upper border, free and rounded, is covered by mucous membrane, and forms the lower vocal cord. In front it is united to the thyroid cartilage; and be- hind to the base of the arytaenoid. 11 View of the Vocal Cords ANP Crico-thyroid Liua- MENTS. 1. True vocal cord. 2. Post, crico-arytaen niascle. 3. Cricoid cartilage. 4. Aryifpnoid cartilage. 5. Sacculus laryngis. 6. Crico-thyroid membrane. 162 DISSECTION OF THE LARYNX. The ligament is partly concealed by the crico-thyroid muscle, and some small apertures exist in it for the passage of fine arteries into the larynx. The strong forepart of the ligament serves the purpose of uniting the two large laryngeal cartilages; and the lateral piece, closing the larynx, ends above in the vocal cord. A capsular ligament surrounds the articular surfaces between the side of the cricoid and the lower cornu of the thyroid cartilage. Its fibres are strongest behind. A synovial membrane lines the capsule. This joint admits forward and backward movements of the thyroid car- tilage, by which the condition of the vocal cords is altered. If that carti- lage is moved forwards the cords are stretched, and if backwards the cords are relaxed. Articulation of the cricoid and arytcenoid cartilages. The articular surfaces of the cartilages are retained by a loose capsule, and possess a synovial sac. The capsular ligament is fixed to each cartilage around its articular surface ; and one part — posterior ligament, is strongest on the inner and posterior aspects. A loose synovial meinhrane is present in the articu- lation. The arytienoid cartilage glides freely forwards and backwards, inwards and outwards; but if its horizontal movements are controlled by muscular action, it can be rotated around a vertical axis, the anterior spur being moved inwards and outwards. Obviously the state of the vocal cords will be changed by the movements of the cartilages. When the arytsenoids glide in and out the cords will be approximated and separated; when backwards and forwards, the cords will be tightened and relaxed ; and in rotation the cords will be moved away from, and brought towards each other. A kind of capsule, formed of thin scattered fibres, with a synovial sac, unites the apex of the arytcenoid cartilage with the hollowed base of the capitulum of Santorini. Sometimes these cartilages are blended together. Fibrous bands (thyro-arytaenoid) join the thyroid with the arytcenoid cartilages, and have been examined as the vocal cords (p. 156). Ligaments of the epiglottis. A band, thyro-epiglottidean, connects the lower part of the epiglottis to the thyroid cartilage, close to the excavation in the upper border of the latter (fig. 42). Some fibrous and ela.stic tis- sues— hyo-epiglottid ligament, connect likewise the front of the epiglottis to the hyoid bone. Structure of the Trachea. The air tube consists of a series of pieces of cartilage (segments of rings) (fig. 40), which are connected together by fibrous tissue. The interval between the cartilages at the back of the tube is closed by fibrous membrane, and by muscular fibres and mucous glands. The trachea is lined by mucous membrane with subja- cent elastic tissue. Cartilages. The pieces of cartilage vary in number from sixteen to twenty. Each forms an incomplete ring, which extends about three- fourths of a circle ; and each is convex forwards, forming the front and sides of the air tube. Botli above and below, the cartilaginous pieces are less constant in size and form : for towards the larynx they increase in dei)th, whilst in the op])osite direction they may be slit at their ends or blended together ; and the lowest j)iece of cartilage is shaped like the letter V. A fibrous tissue is continued from one to another on both aspects, though LOXGUS COLLI MUSCLE. 163 in greatest quantity externally, so as to incase and unite them ; and it is extended across the posterior part of the air tube. Dissection. On removing for about two inches the fibrous membrane and the mucous glands from the interval between the cartilages at the back of the trachea, the muscular fibres will appear. After the muscular fibres have been examined the membranous part of the tube may be slit down, to see the elastic tissue and the mucous mem- brane. Muscular fibres. Between the ends of the cartilages is a continuous layer of transverse bundles of unstriated muscle, which is attached to the truncated ends and the inner surface of the cartilages. By the one sur- face the fleshy fibres are in contact with the membrane and glands, and by the other with the elastic tissue. Some longitudinal fibres are super- ficial to the transverse ; they are arranged in scattered bundles, and are attached to the fibrous tissue. The elastic tissue forms a complete lining to the tracheal tube beneath the mucous membrane ; and at the posterior part, where the cartilages are deficient, it is gathered into strong longitudinal folds. This layer is closely connected with the mucous membrane covering it. Tlie mucous membrane of the trachea lines the tube, and resembles that of the larynx in being furnislied with a columnar ciliated epithelium. Connected with this membrane are numerous branched mucous glands of variable size. The largest are found at the back of the trachea, in the interval between the cartilages, where some are placed beneath the fibrous membrane with the muscular fibres, and others outside that layer. Other smaller glands occupy the front and sides of the trachea, being situate on and in the fibrous tissue connectins: the cartilasfinous rinjrs. Section XVIII. PREVERTEBRAL MUSCLES AND VERTEBRAL VESSELS. Directions. On the part of the spinal column that was laid aside after the separation of the pharynx from it, the student is to learn the deep muscles on the front of the vertebn^. Dissection. The prevertebral muscles will be prepared by removing the fascia and areolar tiss'ue. The muscles are three in number on each side (fig. 45), and are easily distinguished. Nearest the middle line lies the longus colli — this is the longest ; the muscle external to it, which reaches to the head, is the rectus capitis anticus major ; and the small muscle close to the skull, which is external to the last and partly concealed by it, is the rectus capitis anticus minor. The smaller rectus muscle is often injured in cutting through the basilar process of the occipital bone. The LONGUS COLLI muscle (fig. 45, ^) is situate on the bodies of tlie cervical and upper dorsal vertebra3, and is pointed above, but larger below. It consists of two parts — internal and external, the former being vertical, and the latter oblique in direction, as on the right side of the figure. The internal part arises by fleshy and tendinous processes from the bodies of the two upper dorsal and two lower cervical vertebrae ; and the external piece takes origin from the anterior transverse processes of four 164 DISSECTION OF THE NECK. cervical vertebrae (sixth, fifth, fourth, and tliird) Both parts of the mus- cle are blended above, and the whole is inserted by four slips into the bodies of the four upper cervical vertebra). Some of the lowest fibres of the muscle are attached separately by ten- don to the anterior transverse process of one or two of the lower cervical vertebrae. Fig. 45. A. Longus medius. B. Rectus capitis auticus major, c. Scalenus auticus. D. Scalenus medius. F. Scalenus posticus. G. Rectus capitis anticus minor. Deep Muscles of the Frokt of the Neck and the Scaleni Muscles, In contact with the anterior surface of the muscle is the pharynx. The inner border is at some distance inferiorly from the muscle of tlie opposite side, but superiorly only the pointed anterior common ligament of the ver- tebrae separates the two. The outer border is contiguous to the scalenus, to the vertebral vessels, and to the rectus capitis anticus major muscle. Action. Botli muscles bend forwards the neck ; and the upper oblique fibres of one will turn the neck and head to the same side, by the attach- ment to the atlas. The RECTUS CAPITIS ANTICUS MAJOR (fig. 45, ^) is external to the preceding muscle, and is largest at the upper end. Its origin is by pointed tendinous slips, with the longus colli, from the summits of the anterior transverse processes of four cervical vertebrae (sixth, fifth, fourth, and third) ; and the fibres ascend to be inserted into the basilar process of the occipital bone, in front of the foramen magnum. The anterior surface of the muscle is covered by the pharynx, and by the carotid artery and the numerous nerves near the base of the skull. The muscle j)artly conceals the following one. At its insertion the rectus is fleshy, anS, ascends for a short distance into the frontal lobe. The posterior, limb, the continuation of the fissure, is directed obliquely U])wards and backwards to about the middle of the outer face of the hemi- sphere. At its extremity it is sometimes divided into smaller sulci. Fissure of Rolando (i?, fig. GO). Beginning above, about half way along the hemisphere, in or near the longitudinal fissure of the cerebrum, it is prolonged outwards between the frontal and parietal lobes nearly to the j)Osterior part of the Sylvian fissure, — about the middle of that limb. The external parieto-occipital fissure (opposite P 0, fig. 60) begins in the median longitudinal fissure half way between the preceding and the hinder end of the hemisphere. It is very variable in. extent, being some- times an inch long, and at others only a slight indentation ; but it may be always recognized by its continuity with the perpendicular f ssure on the inner face of the hemisphere (fig. 62). Lobes of the Hemisphere. Each hemisphere is divided into five lobes, which have the following names and limits : — The fi'ontal lobe (Pr, fig, 60) forms the anterior half of the hemisphere. It is limited below by the fissure of Sylvius, S, and behind by tlie fissure ' In the following description of the surface anatomy of the cerebrum I have followed chiefly the arrangement of Professor Turner in liis paper "On the Con- volutions OF THE Human Cerebrum;" and to hi»i I am indebted for permission to copy the wood-cuts employed in illustration of his publication. 13 194 DISSECTION OF THE BRAIN, of Rolando,^ 7?. Its under part, which rests on the orbital plate, has been called the orbital lobule. The parietal lobe {Par, fig. GO) is placed behind the preceding, and reaches down to the Sylvian fissure. It is about half as long as the fron- tal. In front it is bounded by the fissure of Rolando, R, and behind by the parieto-occipital {P 0). Tlie upper and hinder part, close to the median fissure, is named the parietal lobule (5^). Lobes op the Hemisphere, and Convolutions Fr. Frontal lobe. Par. Parietal lobe. Oc. Occipital lobe. T S. Teinporo-sphenoidal lobe. E. Fissure of Rolando. 8. Posterior. '8. Ascending limb of the Sylvian fissure. P 0. Place of the external parieto-occipital fissure "which is not visible in a side view. IP. Intra-parietal sulcus. A. P. Parallel sulcus — 1, inferior; 2, middle ; and 3, superior frontal gyrus; AND Fissures of the Outer Surface. 4, ascending frontal ; and 5, ascending parietal gyrus ; 5', parietal lobule; 6, angular gyrus ; 7, superior ; 8, middle ; and 9, inferior teniporo-sphenoidal gyrus ; 10, superior ; 11, middle ; and 12, inferior occipital convolution. Supra- marginal convolution — a, first; 6, second ; c, third ; and d, fourth, annectant gyrus. The occipital lobe {Oc, fig. CO) constitutes the pointed end of the hemi- sphere, and measures about a fifth of the whole. In front it is separated from the parietal lobe by the parieto-occipital fissure {P 0), but below it blends with the following lobe. It rests on the tentorium. On the inner surface is a triangular piece, the occipital lobule {^^, fig. 62). The temporo-sphenoidal lobe (T S, fig. GO) projects into the middle fossa of the base of the skull. It is situate behind the fissure of Sylvius, and below the parietal and occipital lobes. The outer sniface is in contact with the cranium, and the opposite is supported mainly on the tentorium. The central lobe or the island of Reil {C, fig. Gl) lies in tlie sylvian fis- sure, and is concealed by the overlapping of tlie frontal and temporo-sphe- noidal lobes. On separating those lobes it will be seen to be bounded in • By some the anterior limb of the fissure 'S is made the hinder bound of the lobe ; but this is not so good an anangement as that in the text. OUTER CEREBRAL CONVOLUTIONS. 195 front and behind by the limbs of the Sylvian fissure, and externally by a deep groove separating it from the frontal and parietal lobes. It is of a triangular form with the apex down. Convolutions of the Cerebrum. In different brains the convolu- tions vary slightly in form, and even in the two liemispheres of the same cerebrum they are not exactly alike : but there is always similarity enough for the recognition of the chief eminences. Each lobe possesses convolutions, but these run into each other by means of smaller gyri, either on the surface of the brain or at the bottom of tlie sulci ; and the student may experience some difficulty at first in defining the limits of each. It is in the smaller gyri that the greatest variation will be found. A. Convolutions of the Obter Surface. About the middle of the hemisphere are two straight vertical convolutions, one on each side of the fissure of Rolando, i?, which will serve as a starting point. In front of tliose two the convolutions are longitudinal ; and behind they take an oblique direction to the back of the brain. a. The frontal convolutions (fig. 60) form two sets, one on the outer, the other on the under surface of the frontal lobe : those on the outer aspect are four, viz., one vertical or posterior, and three longitudinal or anterior, as follows : — The ascending frontal (*) is the vertical, straight convolution, which bounds in front the Rolando fissure. It reaches down from the median to the sylvian fissure (posterior limb). Along the anterior border it is joined by the three frontal convolutions ; and below it unites with the most ante- rior convolution of the parietal lobe round the lower end of the fissure of Rolando, R. The three longitudinal frontal convolutions are much subdivided and blended, and are separated by two intervening sulci. They are named superior (^), middle Q)^ and inferior (}) : they communicate behind by secondary gyri with the ascending frontal (*), the highest having often two processes ; and are directed forwards one outside another to the anterior extremity of the hemisphere. The under or orbital surface of the frontal lobe, concave, is represented in fig. 01. Near the inner margin is a sulcus, the olfactory, lodging the olfactory nerve ; and internal to it is the lower end of the marginal convo- lution ('7). External to the sulcus lies a convolution, which is pointed behind, but widened and subdivided in front, and incloses smaller gyri and sulci within its coil : this has been subdivided into three parts, an inner C^), a posterior (^),and an external (^). b. The parietal convolutions (fig. 60), like the outer frontal, are four in number ; an anterior, or ascending, Avhich is vertical along the fissure of Rolando, and three directed back from it. The ascending parietal (^), narrow and straight, limits behind the fissure of Rolando, and reaches from the middle line to the hinder limb of the Sylvian fissure, *S'. Above, it runs into the parietal lobule,^' ; and below, it joins the ascending frontal round the lower end of the fissure of Rolando. Behind it is separated from the other gyri of the parietal lobe by a suclus, IP} The parietal lohiile (^') appears to be an appendage to the upper end of ' Tlie intraparietal sulcus (IP, fig. 60, Turner), 'is placed between the ascending parietal and the supra-marginal convolution, A. Above, it is directed back near the upper part of the hemisphere, separating the parietal lobule (5') and the supra-marginal convolution, A. 196 DISSECTION OF THE BRAIN the ascending convolution, and is continued back along the upper margin of tlie hemisphere as far as the parieto-occipital fissure. Subdivided on the surface into two chief parts it is joined behind to the occipital lobe by tiie small annectant gyrus (a). To its outer side lies the upper part of the intraparietal sulcus ; and here it joins usually the following convolution, A. The supra-marginal convolution A, lying outside and below the preced- ing, is interposed between the intraparietal sulcus, / P, and the Sylvian fissure (outer end). Variable in shape it joins, below, the ascending parietal convolution (^) ; it may communicate above with the parietal lobule, and behind with the following. The angular convolution (*), very complicated and not well defined, is placed at the extremity of the hinder limb of the Sylvian fissure, and is composed of two or three pieces Fig. 61. Above it is the parietal lobule ; and below, the temporo-sphenoidal j^^ ^--.. lobe which it joins. In front lies 1/ \ \ ^. the supra-marginal convolution ; ' • i ' \ r^nd behind, the occipital lobe, with which it blends by the small annect- ant gyrus (6). c. The occipital convolutions (fig. GO) are small and very much di- vided, so that their outline is un- certain. They are three in number, lying one above another, and sepa- rated by sulci, something like the frontal gyri at the opposite end of the hemisphere. The upper (^°), forming part of the margin of the longitudinal fis- sure, receives an annectant gyrus from the parietal lobule. The middle (^^), crossing out- wards the hemisphere, has two an- nectant gyri to other convolutions; one (6) joining it above to the an- gular convolution, and another (c) passing to the middle temporo- sphenoidal convolution. The inferior ('^) occupies the tip of the hemisphere between the up- per and under surfaces. At the inner end it is continuous witli the upper gyrus ; and at the outer end with the inferior temporo-S{)henoi- dal convolutioti (") by an annectant gyrus {d). d. The temporo-sphenoidal convolutions (fig. GO), three in number, run from above down, and are separated from one another by two sulci. The superior {J) bounds posteriorly the horizontal limb of the Sylvian fissure. At the upper end it is connected by a gyrus with the angular convolution. The middle {^) is separated from the first by the parallel sulcus (P). View of the Orbital Lobule and the Central Lobe. C. Island of Reil or median lole. 0. Olfactory salens. 2. Internal ; and 6. External orbital convolution. posterior ; 17. Marginal convolution of the hemisphere INNER CEREBRAL CONVOLUTIONS. 197 Above, it blends commonly with the angular convolution, and is connected to the middle occipital convolution by an annectant gyrus (c). The inferior C), less well marked than the other two, forms part also of the inner surface of the temporo-sphenoidal lobe. By the upper end it is united to the third occipital convolution by an annectant gyrus (d). The parallel sulcus (/*, iig. 60), named from its position to the Sylvian fissure, extends from the lower end of the temporo-sphenoidal lobe to the angular convolution. e. The convolutions of the central lohe ( O, iSg. 61), about six in number, are straight for the most part, and are separated by shallow sulci : they are directed upwards from apex to base of the lobe. The posterior gyri are the longest and broadest, and the anterior joins the convolution of the under surface of the orbital lobule. B. The CONVOLUTIONS ON THE INNER SURFACE of the hemisphere (fig. 62) are generally well defined ; but some being so long as to reach beyond the extent of a lobe, the arrangement of them in lobes cannot be followed, as on the exterior. Dissecti07i. Without the use of a separate hardened hemisphere, the parts now to be described will not be seen satisfactorily. If the student possesses only one brain, he may bring into view much of the inner sur- face by cutting of the left hemisphere as low as the white corpus callosum in the median fissure. Convolution of the corpus callosum^ gyrus fornicatus (^®), is long and simple, and arches round the body from which it takes its name. Begin- ning at the base of the brain in the anterior perforated spot, it bends backwards in contact with the corpus callosum {Cal), and below the back of that body blends by a narrowed part with the uncinate convolution Q^) of the temporo-sphenoidal lobe. Anteriorly a sulcus separates it from the following convolution ; and smaller gyri often connect the two across that sulcus. The marginal convolutioti (^^) is named from its position on tKe edge of the median fissure. Its extent is rather more than half the length of the hemisphere, for it begins in front at the anterior perforated spot, and ter- minates near the back of the corpus callosum, just behind the fissure of Rolando. It is much subdivided both internally and externally; and on the under part of the frontal lobe (fig. 61) it lies internal to the olfactory sulcus. Between it and the preceding convolution is situate the calloso- marginal sulcus (^) which marks its hinder limit. The calloso-inarginal sulcus (/, Huxley), designated from its situation, begins in front below the corpus callosum, and ends beliind, near the back of the same body, by ascending to the edge of the hemisphere. Smaller gyri uniting the two bounding convolutions, frequently interrupt it, and secondary sulci are prolonged from it into the same convolutions. The quadrilateral lobule Q^) reaches from the marginal convolution in front to the parieto-occipital fissure behind. It is much divided by sulci, and projects above to the edge of the hemisphere ; it joins below the gyrus fornicatus. The occipital lobule ('^*) is triangular in shape, with the base upwards, at the margin of the hemisphere. Measuring about an inch and a half in depth, it lies between the internal parieto-occipital fi.ssure, PO, and the calcarine sulcus (/). Sulci running from apex to base divide it into four or five narrow convolutions. 198 DISSECTION OF THE BRAIN. Internal perpendicular or parieto-occipital fissure {PO, fig. 02) sepa- rates the two preceding lobules. Continuous with the external fissure of the same name, it opens below into the following. The calcarine sulcus /, (Huxley) is directed across the back of the hemisphere below the level of the corpus callosum, and ends in front at the gyrus fornicatus ('®), whose hinder limit it marks. It receives above Fiff. 62. Convolutions and Fissures on the Inner Face of the Hemisphere. P. 0. Internal parietooccipital fissure. 18. Convolution of corpus callosum. Cal. Corpus callosum, cut. 18'. Quadrilateral lobule. i. Calioso-marginal sulcus. 19. Uncinate gyrus. I. Calcarine sulcus. 19'. Crotchet or hook of the uncinate gyrus, m. Dentate sulcus. 25. Occipital lobule. «. Collateral sulcus. 9. Inferior temporo-sphenoidal gyrus partly 17. Marginal gyrus. seen. the internal perpendicular fissure; and it sinks into the posterior cornu of the lateral ventricle, forming the eminence of the hippocampus minor. Internal temporo-sphenoidal convolutions (fig. 62) are two in number, viz., the uncinate and dentate, and occupy the tentorial surface of the hemisphere. The uncinate or hippocampal convolution (^') is prolonged from the posterior end of the hemisphere nearly to the tip of the temporo-sphenoidal lobe. It is somewhat narrowed in the middle, where the gyrus fornicatus blends with it ; and is enlar<]jed at each end, especially at the posterior where it is subdivided by sulci. Below it is a long curved sulcus, the collateral (n) ; and above it are the calcarine (/), and the dentate sul- cus (m). From the anterior extremity a narrow part (^^', uncus) is pro- longed back for half an inch on the inner side, like a hook. Below the uncinate convolution is part of the inferior temporo-sphe- noidal convolution (^), before described, which forms the lower edge of the temporo-sphenoidal lobe, appearing more largely on the inner than on the outer face. The collateral sulcus n, (Huxley) courses along tlie lower border of the uncinate convolution ; it projects into the inferior cornu of the lateral ventricle, and gives rise to the prominence of the eminentia collateralis. Secondary sulci emanate from it, and it is often interrupted by cross The dentate sulcus m^ (Huxley) is the deep groove at the upper edge of the uncinate convolution ('^j, and corresponds with the prominence of the CORPUS CALLOSUM. 199 hippocampus major in the descending cornu of the lateral ventricle. Upwards it is limited by the corpus callosum {Cal) and downwards it intervenes between the hook and the body of the uncinate convolution. In the dentate sulcus is the gray substance of the hemisphere, which presents a notclied border at the inner edge of the temporo-sphenoidal lobe ; this has been called the dentate convolution, and will be better seen in a subsequent stage of the dissection of the brain. Structure of the convolutions. Each convolution is continuous with the interior of the brain on the one side (base) ; and is free on the surface of the brain on the other side, where it presents a summit and lateral parts. On a cross section it will be seen to consist externally of gray cerebral substance as a cortical layer, which is continued from one eminence to another over the surface of the hemisphere ; and internally it is composed of white brain substance — the medullary part, which is derived from the fibrous mass in the interior. The cortical layer is composed of two, or in some parts of three strata, which are separated by their intervening paler layers ; and an outer white stratum, which covers the surface, is most marked over the internal and lower portions of the uncinate convolution. IxTEiiiOR OF TfiE Cerebrum. The cerebrum consists on each side of a dilated part or hemisphere, and of a stalk or peduncle. In the interior is a large central space, which is subdivided into smaller hollows or ven- tricles by the before-mentioned connecting pieces. And the whole, except the peduncle, is surrounded by a convoluted crust. In conducting the dissection of the cerebrum, the student will learn the form and situation of the several constituent parts, and the connections between these by means of fibres. Dissection. Supposing both hemispheres entire, the left is to be cut off to the level of the convolution of the corpus callosum. When this has been done, the surface displays a white central mass of an oval shape (centrum ovale minus), which sends processes into the several convolu- tions. In a fresh brain this surface would be studded with drops of blood escaping from the divided vessels. Next, the convolution of the corpus callosum is to be divided about the middle, and the two pieces are to be thrown backwards and forwards. Under it lies a thin narrow band, the covered band of Reil, which bends down before and behind the corpus callosum. The same steps of the dissection are to be taken on the opposite side ; and the tops of the hemispheres being removed to the level of the coqms callosum, the transverse fibres of that body are to be defined as they radi- ate to the convolutions. Now a much larger white surface comes into view (larger ovan centre), which has been named centrum ovale, Vieussens ; and the white mass in each hemisphere is seen to be continuous, across the middle line, through the corpus callosum. Tiie corpus callosum reaches from the one-half of the cerebrum to the other, and forms the roof of a space (lateral ventricle) in each hemisphere. Between the halves of the brain, where it occupies the longitudinal fissure, it is of small extent, being about four inches in length, and somewhat arched from before backwards. It is narrower in front tlian behind, and extends nearer to the anterior than the posterior part of the cerebrum. In front the corpus callosum is bent to the base of the brain (fig. o9, w), as before described (p. 192); and behind it ends in a thick roll, which is connected with the subjacent fornix. 200 DISSECTION OF THE BRAIN. On the upper surfjice the fibres are directed from the hemispheres to the middle line — the middle being transverse, but those from the anterior and posterior parts oblique. Along the centre is a ridge or niphe, and close to it are two or more slight longitudinal white lines (nerves of Lancisi). Still further out may be seen other longitudinal lines (covered band), beneath the convolution of the corpus callosum, if all of them have not been taken away in the removal of that convolution. The longitudinal fibres in the middle line are continued downwards in front, and joining the covered band or fillet are continued to the anterior per- forated spot. Dissection. In order to see the thickness of the corpus callosum, and to bring into view the parts in contact with its under surface, a cut is to be made through it on the right side about half an inch from the central ridge : and this is to be extended forwards and backwards, as far as the limits of the underlying ventricle. Whilst cutting through the corpus callo- sum, the student may observe that a thin membranilbrm structure lines its under surface. The corpus callosum is thicker at each end than at the centre, in con- sequence of a greater number of fibres being collected from the cerebrum ; and the pt)sterior part is the thickest of all. Connected with its under surface along the middle is the septum lucidum or partition between the ventricles (fig. G3, h)^ and still posterior to that is the fornix. This body is the chief commissural part of the halves of the brain, and reaches laterally even to the convolutions, but its fibres are not distinct far in the hemisphere. Dissection. The left lateral ventricle is to be now opened in the same way as the right ; and to prepare for the examination of the cavity on the right side, as much of the corpus callosum as forms the roof of the space is to be removed. A pai-t of the ventricle extends down in the temporo- sphenoidal lobe towards the base of the brain ; and to open it, a cut is to be carried outwards and downwards, through the substance of the hemi- sphere, along the course of the hollow. (See fig. 63.) Ventricles of the brain — The ventricular spaces in the interior of the cerebrum are derived from the subdivision of a large central hollow, and are five in number. One (lateral) is contained in each lu^misphere ; and these constitute the first and second. The third occupies tlie middle line of the brain near the under surface ; and the small fiftli is included in the partition between the lateral ventricles. The fourth is situate be- tween the cerebellum and the posterior surface of the medulla oblongata and pons. The lateral ventricles (fig. 63) are two in number, one in each hemi- sphere ; they are separated incompletely in the middle line by a septum, as they communicate by iui ai)erture below that partition. The interior is lined by a thin stratum of areolar tissue covered by nucleated epithelium (the ependyma ventriculorum), with cilia at some spots. P^ach is a narrow interval, which rt^aches into the anterior, posterior, and middle regions of the corresponding hemisphere. Its central part (body) is almost straight, but the extremities (cornua) are curved. Thus there are three cornua in each, which have the following disposition : — The anterior is directed outwards from its fellow in the other hemisphere. The posterior or the digital cavity is much smaller in size, and is bent inwards in the occipital lobe towards the one on the opposite side. And the inferior coniu, beginning opposite the posterior fold of the corpus cal- BOUNDS OF LATERAL VENTRICLE 201 losum (a), descends in a curved direction in the temporo-sphenoidal lobe, with the concavity of tlie bend turned inwards. For the purpose of examining its boundaries, tlie ventricle may be di- vided into an upper or horizontal, and a lower or descending part. The upper or iiorizontal portion reaches from the frontal to the occipital lobe, and is shaped like the italic letter /; View of the Lateeal Ventricles: on the left side the Descendi.vq Corxc is laid OPEX. (From a cast ia a museum of University College, Loudon.) a. Kemains of the corpus callosum. g. Optic thalamus. 6. Septum luciduni, iuclosiug the small space /*. Choroid plexus. of the fifth ventricle. ^ i Hippocampus minor. c. Fornix, fc. Eminentia coUatfralis. d. Posterior crus or tajnia of the fornix. I. Hippocampus major. e. Corpus striatum. o. Digital fossa. /. Taenia semicircalaris. The roof is formed by the corpus callosum. The floor is irregular in outline, and presents from before backwards the following objects ; — first, a small piece of the under part of the corpus callosum ; next, a large, gray body, the corpus striatum (^,g), which is situate above the posterior commissure, and between the anterior pair of the corpora quadrigemina. In sha|)e like the cone of a pine, it is about a quarter of an inch in length, and has the base or wider part turned for- wards. It is connected to the optic tlialami by two white bands, — [)edun- cles of the pineal body (/' ) : these begin at the base, and extending for- wards, one on each side along the inner part of the thalamus, end by joining the crura of the fornix. At the base of the gland is a band of trans- verse white fibres which unites it which the posterior commissure. This body is of a red color and vascular, and incloses two or more cells containing a thick fi.:id, with amyloid bodies, and a calcareous material (brain sand) consisting of particles of phosphate and carbonate of lime, and phosphate of magnesia and ammonia^ In its substance are large pale nucleated cells. The corpora, quadrigemina (fig. G8) t^re four small bodies, which are arranged in pairs, right and left, and are separated by a median groove. Each pair is situate on the upper aspect of the cerebral peduncle of the same side. The anterior eminence (^, nates) is somewhat larger than the posterior, from which it is separated by a slight depression ; it is oblong from before backwards, and sends forward a white band to join the optic tract and thalamus. The posterior eminence (/, testis) is rounder in form and whiter in color than the preceding : it has also a lateral white band wiiicli is directed beneath the corpus geniculatum internum, and blends with the peduncular fibres in the thalamus opticus. Tliese bodies are small masses of gray substance enveloped by white, and are placed on the band of the fillet which forms the roof of the aque- duct of Sylvius. The processes (brachia) to the optic thalamus are acces- sory parts to the peduncular fibres ef the cerebrum (p. 209). Fillet of the olivary body. If the upjjcr margin of the cerebellum be ' These particles are referred to by KoUiker, as pathological products ; and the concentrically arranged uiasses amongst them ai'e said to be incrustations of fibrin coagula. FIBRES OF CEREBRUM. 209 pulled aside, a white band, about a quarter of an inch in width, will be seen to issue from the transverse fibres of the pons, and to bend upwards over the peduncle of the cerebellum to the corpora quadrigemina (fig. This is the upper or commissural piece of the fillet (p. 128), which passes beneath the corpora quadrijjemina, and joins with the similar part of the opposite side over the Sylvan aqueduct. Structure of the Cerebrum. In each cerebral hemisphere three principal sets of constituent fibres are recognized, viz., diverging, trans- verse, and longitudinal. The former are in part derived from the spinal cord ; while the two latter, joining distant pieces of the cerebrum, are con- sidered to be only connecting or commissural in tlieir office. Pedimcular or diverging Jibres (fig. 56). In the crus cerebri two bundles of longitudinal fibres are collected; these are separated, in part, by gray matter, and are derived from the medulla oblongata (p. 191). JJissection, A complete systematic view of the diverging fibres can- not be now obtained on the imperfect brain. At this stage the chief |)ur- pose is to show the passage of the radiating fibres from the crus through the two cerebral ganglia. To trace the diverging fibres onwards beyonds the crus cerebri, and througli the corpus striatum, the nucleus caudatus of this body should be scraped away (fig. 65) ; and the dissection should be made on the left side on which the striate body and the optic thahimus remain uncut. In this proceeding the pecten of Reil comes into view, viz., gray matter passing between tlie white fibres in the corpus striatum, and giving the appearance of the teeth of a comb. On taking away completely the prolonged part of the nucleus caudatus, others of the same set of fibres will be seen issuing from the outer side of the optic thalamus, and radiating to the posterior and inferior lobes. After tracing those fibres, the upper part of the optic thalamus may be taken away at the posterior end, to denude the accessory bundles to the peduncular fibres, from the corpora quadrigemina and the superior pedun- cle of the cerebellum (fig. 65, ^) : the last band lies beneath the corpora quadrigemina. T\\g\y arrangement (fig. 65,^). Some of the diverging fibres radiate from the peduncle of the cerebrum to the sui-face of the hemisphere, pass- ing in their course through the two cerebral ganglia (optic thalamus (^) and corpus striatum (^) ), and they form a conically-shaped bundle, whose apex is below and base above. The fibres forming the free or fasciculated part (crust) of the peduncle (fig. 56) pass through the striate body. The fibres on the opposite aspect, which form the tegmentum (fig. 57, o?), are transmitted through tlie under part of the optic thahimus, and through the cor[)US striatum, reaching as far forwards as, but much farther back than tliose of tlie crust. In the thalamus and the corpus striatum the fibres are greatly increased in number. The upper or sensory set receive also accessory bundles from the superior peduncle of the cerebellum (fig. 65, ') in the crus cerebri (p. 191); and from the pair of the cor{)ora quadrigemina, and the corpora geniculata of the same side, in the thalamus. On escaping from the striate body and the thalamus, the fibres decussate with the converging fibres of the corpus callosum, and radiate then into the anterior, middle, and posterior parts of the cerebral hemisphere, form- ing the corona radiata. In the hemisphere the fibres are continued to 14 210 DISSECTION OF THE BRAIN. the convolutions : their expansion in tlie hemisphere resembles a fan bent down in front and behind, forming thus a layer wliich is concave on the under side. Their extent. All the fibres of the peduncle do not reach the surface of the brain, for some end in the corpus striatum and the optic thalamus, especially in the former. And some of the fibres in the convolutions begin in the ganglionic bodies before mentioned, and extend to the surface of the hemisphere.^ Thus, in addition to the fibres continued throughout, viz., from the crus to the surface, some unite the peduncle of the cerebrum with the ganglia, and others connect the ganglia with the convolutions on the exterior. Fig. 65. 1. Superior peduncle. 2. Middle, and 3, inferior pcduncleof the cerebellum. 4. Process from the fillet of the oli- vary body to the corpora qiiadri- gemina: on the right side it is cut and reflectfd. 5 Posterior pyramid. 6. Continuation of the lateral tract into the optic thalamus. 7. Corpora quadrigemiua. 8. Optic thalamus. 9. Corpus striatum. 10. Corpus callosum. Connection posteriorlt between the Cerkbkum and the Meddlla Oblongata and Cerebellum. Their source. The fibres thus entering inferiorly the cerebrum through its peduncle, and continued thence to the periphery of the hemisphere, are derived from the component pieces of the medulla oblongata except the restiform body (fig. 57), viz., from anterior pyramid, lateral column and olivary body, and posterior pyramid (p. 183) : they serve to connect the spinal cord with the cerebrum. The decussation between opposite sides has been before referred to (p. 186). The transverse or commissural Jihres connect the hemispheres of the cerebrum across the middle line. They give rise to the great commissure or the corpus callosum (p. 210) : and to the anterior and posterior com- missures (p. 207). Those bodies have been already examined. Longitudinal Jihres. Other connecting fibres pass from before back- wards, uniting together parts of the same hemisphere. The chief" bands of this system are the following, the fornix, the taenia semicircularis, and the peduncles of the pineal body. Other longitudinal fibres may be enu- ' According to some authors none of the fibres of the peduncle reach farther than the corpus striatum and the optic thalamus. SURFACES OF CEREBELLUM. 211 tnerated on the upper and under surfaces of the corpus callosnm, along the middle line, together with the band of the convolution of the corpus caU losum : these fibres are connected with the anterior perforated spot of the base of the brain. Structure of the optic thalamus. The thalamus is about an inch deep, and the following is a summary of its structure, as displayed in the pre- vious dissections. The upper and inner half is formed chiefly of gray matter, with which the undermentioned white bands are connected : Thus through it pass the fornix in front, and the posterior commissure behind ; whilst the pedun- cles of the pineal body lie along the inner side, and the taenia semicircu- laris along the outer. The lower and outer part consists mainly of white fibres directed upwards, and these are derived from the peduncle of the cerebrum in- feriorly, and from the peduncle of the cerebellum and the corpora quadri- gemina superiorly : to the hinder part of them two slips of fibres are added from the corpora geniculata. The corpora geniculata contain gray substance inside. Into these bodies fibres of the optic tract enter ; and from each issues a band to join the fibres of the crus cerebi'i. They seem to serve as accessory ganglia to the peduncular fibres of the cerebrum. Corpus striatum. By slicing through the corona radiata on the left side, so as to bring into view the extraventricular nucleus of the corpus striatum, the extent and form of that mass, and the situation of the ante- rior commissure in it, will be apparent. Grus cerebri. By a vertical section through the left peduncle of the cerebrum, the disposition and the thickness of the two layers of its longi- tudinal fibres ; and the situation and extent of the locus niger between them, may be perceived. Section V. THE CEREBELLUM. Dissection. The cerebellum (fig. 59, h) is to be separated from the remains of the cerebrum, by carrying the knife through the optic thala- mus so that the small brain, the corpora quadrigemina, the crura cerebri, the pons, and the medulla oblongata, may remain united together. All the pia mater is to be carefully removed from the median fissure on the under surface ; and the different bodies in that fissure are to be sepa- rated from one another. Lastly the handle of the scalpel should be passed along a sulcus at the circumference, which is continued from the crus, be- tween the upper and under surfaces. The cerebellum, little brain (fig. &^), is flattened from above down, so as to be widest from side to side, and measures about four inches across. This part of the encephalon is situate in the posterior fossfe of the base of the skull, beneath the tentorium cerebelli. Like the cerebrum, it is in- completely divided into two hemispheres ; the division being marked by a wide median groove along the under surface, and by a notch at the poste- rior border which receives the falx cerebelli. 21^ DISSECTION OF THE BRAIN Upper Surface. On the upper aspect the cerebellum is raised in the centre (fig. G8), but slopes towards the circumference. There is not any median sulcus on this surface ; and the halves are united by a central con- stricted j)art — the superior vermiform process. Se{)arating the upper from the under surface, at the circumference, is the horizontal Jiss are, which is wide in front, and extends' backwards from the pons Varolii to the middle line of the cerebellum. The UNDER SURFACE is couvcx, being received into the fossae of the base of the skull, and is divided into hemispheres (fig. 66) by a median hollow (vallecula). USDEB PART OF THE CEREBELLUM, SEEN FROM BEHIND, THE MeDPLLA OBLONOATA, 6, BEING CUT AWAY IN GKEATEH PAKT. a. Pons Varolii. c to e. Inferior vermiform process, consisting 2/. Medulla oblongata, cat through. of;— c. Uvula, d. Pyramid, e. Com- missural laminae. Lobes of each half of the Cerebellum on the Under Surface. /. Snbpeduncnlar. k. Posterior. g. Amygdaloid. 3 Third nerve attached to the crus cerebri. h. Biventral. 6. Two roots of the fifth nerve attached to the i. Slender. side of the pons Varolii. The central jissure, or the vallecula, is wider at the middle than at either the anterior or the posterior end, and receives the medulla oblongata. In the bottom of the fissure is a mass named inferior vermiform process (fig. 66, c to e), which corresponds with tiie central part connecting the halves of the cerebellum on the upper surface. The two vermiform processes constitute the general commissure of the halves of the cerebellum. Constituents of the vermiform process. In the inferior vermiform pro- cess are the following eminences, which may be easily separated from one another with the handle of the scalpel : — Most anteriorly is a narrow body, the uvula (fig. 66, c), which is named from its resemblance to the same ])art in the throat ; it is longer from before backwards tlian from side to side, and is divided into laminae. Its anterior projection into the fourth ventricle is named nodule^ or laminated tubercle (fig. 67) ; and on the side is a band of giay matter with ridges and sulci, the furrowed hand. (fig. 67, c?), wliich unites it with 'the almond-like lobe of the hemisphere. Connected with the nodule is a thin white layer, — the medullary velum LOBES OF THE CEREBELLUM. 213 (h) ; but this, and the furrowed band will be seen in a subsequent dissec- tion (p. 214). Behind the uvula is a tongue-shaped body, named pyramid (fig. 66, under surface, let the knife be carried vertically through the centre of the vermiform processes ; and then the structure of the central uniting part, as well as the boundaries of the fourth ventricle, may be observed on separating the halves of the cerebellum. Fig. 68. View of the Third and Fourth Ventricles. The formpr being obtained by the removal of the velum interpositum ; and the latter by di vidinjir vertically the verniilorm process of the cerebellnm. (From a cast in the Museum of University College.) The third ventricle is the interval in the middle Hue between the optic thalami, b. k. Valve of Vieussens. a. Corpus striatum. b. Optic thalamus. c. Anterior commissure. d. Middle or soft commissure. (. Posterior commissure. g. Pineal body. /. Pedunclf of the pineal body. h and i. Left pair of the corpora quadrigensina. The fourth ventricle, n, is at the back of the medulla oblangata. I. Upper peduncle of ihe cerebellum, o. Eminentia teres. p. Anterior fossa. r. Posterior fossa. *. Posterior pyramid. 4. Origin of the fourth nerve from the valve of Vieussens. Structure of the vermiform process (fig. 68). The upper and lower vermiform processes of the cerebeJlum are united in one central part, which connects together the hemispheres. The structure of this connecting FOURTH VENTRICLE. 217 piece is the same as that of the rest of the cerebellum, viz., a central white portion and investing laminai. Here the branching appearance of a tree (arbor vitag) is best seen, in consequence of the laminae being more divided, and the white central pieces being longer and more ramified. The FOURTH VENTRICLE (fossa rhomboidalis) is a space between the cerebellum and the posterior surface of the medulla oblongata and pons (fig. 68). It has the form of a lozenge, with the points placed upwards and downwards. The upper angle reaches as high as the upper border of the pons; and the lower, to a level with the inferior end of the olivary body. Its greatest breadth is opposite the lower edge of the pons; and a transverse line in this situation would divide the hollow into two triangu- lar portions — upper and lower. Tlie lower half has been named calamus scriptorius from its resemblance to a writing pen. The lateral boundaries are more marked above than below. For about half way down, the cavity is limited on each side by the superior peduncle of the cerebellum (/), which projecting over it forms part of the roof; and along the lower half lies the eminence of the restiform body (fig. 66^ ^). The roof of the space is somewhat arched, and is formed above by the valve of Vieussens (^), and the under part of the vermiform process ; and below, by the reflection of the pia mater from that process to the spinal cord. The ^oor of the ventricle is constituted by the posterior surfaces of the medulla oblongata and [)ons, and is grayish in color. Along its centre is a median fissure, which ends below, near the point of the calamus, in a minute hole — the aperture of the canal of the cord. On each side of the groove is a spindle-shaped elevation, the fasciculus s. emine7itia teres (o). This eminence reaches the whole length of the floor, and is pointed and little marked inferiorly, where it is covered by gray substance ; but it be- comes whiter and more prominent superiorly, and its widest point is oppo- site the lower border of the pons. Tlie outer border of the eminence is limited externally by a slight groove, which points out the position of two small fossae (fovea anterior et posterior). The posterior (r) is near the lower end of the groove ; and the anterior (/>) is opposite the crus cerebelli. Above the anterior fossa is a deposit of very dark gray substance, which has a bluish appearance as it is seen througli the thin stratum covering it ;^ from it a bluish streak is continued upwards, at the outer edge of the eminentia teres, to the opening in the top of the fourth ventricle. Crossing the floor on each side, opposite the lower border of the pons, are some white lines, which vary much in their arrangement (fig. 55) : they issue from the central median fissure, and enter tlie auditory nerve (p. 181). Besides the objects above mentioned, there are other eminences in tlie floor of the ventricle indicating the position of the nuclei of origin of cer- tain nerves. In the lower half of the space are three slight eminences on each side for the hypo-glossal, vagus, and auditory nerves : that for the hypo-glossal is close to the middle line below, and corresponds with the lower pointed end of the eminentia teres. The other two, outside that eminence, are placed in a line one above another, but separated by a well-marked groove ' Tlie term locus csruleus lias been applied to the spot, and the dark vesicular matter in it has been named substantia ftrriujinea. 218 DISSECTION OF THE BRAIN. (fovea posterior) ; the lower is tlie nucleus of the vagus and glosso-pharyn- geal nerves, and the upper is the nucleus of the auditory nerve. Running into the lower part of the vagus nucleus, is the nucleus of the accessory portion of the spinal accessory nerve. (See p. 189.) In the upper half of the space some other nerves take origin from nu- clei, but there is only one projection. This is placed over the common nucleus of the sixth and the facial nerve : it is a rounded elevation on tlie outer part of the eminentia teres, about a line above the white cross striae on the floor, and close behind the fovea anterior. The fourth ventricle communicates at the upper part with the third ventricle through tlie Sylvian aqueduct ; and with the subarachnoid space of the cord and brain, through an aperture in tlie pia mater intervening between the medulla and the cerebellum: laterally, the ventricular space is extended for a short distance between the cerebellum and the side of the medulla oblongata. The lining of the other ventricles is prolonged into this by the aperture of communication with the third. Covering the floor is a columnar epi- thelium, which is continuous with that in the upper part of the central canal of the spinal cord (Clarke). In this ventricle is a vascular fold — choroid plexus, on each side, simi- lar to the body of the same name in the other ventricles. It is attached to the inner surface of the membrane (pia mater) which closes the ventricle between the medulla and the cerebellum, and it extends upwards on the side of the opening into the sub-arachnoid space. Its vessels are supplied by the inferior cerebellar artery. Gray matter of fourth ventricle. The gray matter forms a surface- covering for the floor of the fourth ventricle. It is continuous below with the gray commissure of the cord, and extends upwards to the aqueduct of Sylvius (p. 187). The special nuclei have been referred to already (p. 217). ARTERIES OF THE HEAD AND NECK, 219 TABLE OF THE CHIEF ARTERIES OF THE HEAD AND NECK, 1. Common < carotid 5-1 1. Brachio-j; cephalic. Hyoid branch 1. Superior thyroid . laryngeal thyroid. 2. lingual . Hyoid branch dorsal lingual sublingual ranine. 'Inferior palatine branch tonsil litic glandular submental 3. facial . , , .- inferior labial ^ inferior coronary . . J ^^^^,i^,. 1 lateral nasal ^angular. 4. occipital 1 Meningeal branch posterior cervical. Stylo-mastoid branch 1. External 5. posterior auricular auricular carotid . -^ mastoid. 6. ascending pharyngeal. Pharyngeal branches meningeal. Auricular parotid articular 7. temporal transverse facial middle temporal anterior temporal .posterior temporal. Inferior dental middle meningeal muscular posterior dental 8. internal maxillary infraorbital spheno-palatine descending palatine vidian pterygo-palatine. n Arteriffi receptaculi. Lachrymal supraorbital central of the retina ciliary 2. ophthalmic . muscular ethmoidal 2. internal - 1 palpebral carotid . 3. antero cerebral 4. anterior communicating 5. middle cerebral 6. posterior commuuicatin L7. choroid. frontal .^nasal. s 1. Vertebral 2. subcli • vian . 2. left common carotid. ^3. left subclavian. 2. internal mammary 3. thyroid axis . . 4, superior intercostal Anterior spinal posterior spinal inferior cerebellar posterior meningeal transverse basilar anterior inferior cerebellar superior cerebellar [^posterior cerebral. r Infra thyroid ■^ suprascapular . [^transverse cervical ) Deep cervical. . Ascending cervical. i Supraspinal infraspinal. i Superficial cervical posterior scapular. 220 VEINS OF THE HEAD AND NECK. TABLE OF THE CHIEF VEINS OF THE HEAD AND NECK. '1. Lateral sinus 2. ascending pliaiyugeal. Brachio-ce- jihalic is formed ly tlie union of Internal ju- gular . . 3. lingual 4. facial f Superior longitudinal i sinus inferior longitudinal sinus ■{ straight sinus occipital sinuses oplitlialmic ven superior petrosal ^inferior petrosal. J Meningeal branches ( pharyngeal. ( Supprflcial dorsal < lingual ( ranine. Angular . inferior palpebral dorsal and lateral nasal veins. anterior internal maxil- laiy Supraorbital frontal palpebral nasal. C Alveolar branches I infraorbital -{ descending palatine uaso-palatiue Lvidlan. a. occipital coronary buccal masseteric lal>ial submental inferior palatine tonsillitic -glandular. Mastoid vein cervical. superior inferior superior thyroid \ Thyroid ( laryngeal. 7. middle thyroid fl. Vertebral . ( Spinal < deep ce ( ascendi ervical ng cervical. fl. Internal maxillary Hubclavian -i 2. external jugular _8. anterior jugular |^ 2. temporal 3. posterior auricular 4. branch to the internal jugular. o. suprascapular transverse cervical ("Middle meningeal I inferior dental ■i deep temporal pterygoid ^masseteric. {Anterior posterior middle temporal parotid anterior auricular transverse facial. J.\uricalar Stylo-mas told. < Supraspinal I infraspinal. J Superficial cervical posterior scapular. CRANIAL NERVES OF THE HEAD AND NECK 221 TABLE OF THE CRANIAL NERVES. 1. First nerve . 2. Second nerve 3. Third nerve 4. Fourth nerve Filaments to the nose. To retina of the eyeball. To muscles of the orbit. To superior oblique muscle. f Meningeal 6. Fifth or tri-facial lachrymal < Lachrymal • ( palbebral. Ophthalmic ., f.ontal . Supraorbital • ( supratrochlear. rTo lenticular ganglion J ciliary nerves .nasal • j infratrochlear l^nasal. ophthalmic or ( Connecting branches 1 To nasal nerve lenticular ■ to the third nerve ganglion. .. ' 1 to sympathetic. ciliary nerves. r Orbital branch . (> Malar • I temporal. superior max-J to Meckel's ganglion illary . . ] posterior dental anterior dental "- infraorbital Internal branches J Nasal • ( nasopalatine. ascsndiug . To the orbit. Meckel's gang- lion ( Anterior palatine descending . < posterior ( external. J Vidian ' I pharyngeal. ^posterior inferior maxil- lary TDeep temporal „ ,, , ^ masseteric Small or muscular part < jj^cc^l [^pterygoid. Auriculo- temporal Jarge or sensory part otic ganglion ( Connecting branches ( branches for muscles. Connecting bran'hes branches to the submaxillary J glands and the ganglion .1 mucous rae-n- brane of the t_ mouth. gustatory ^inferior dental f Articular and to I meatus -j parotid I auricular (^temporal. f To submaxillary I and sublingual •\ ganglia I to hypoglossal l_to the tongue. Mylo-hyoid labial incisor. To Jacobson's uprve the fifth and sym- pathetic. To the gustatory, chorda tyini)ani, and sympathetic. 222 CRANIAL NERVES OF THE HEAD AND NECK, TABLE OF CRANIAL NERVES — Continued, 6. Sixth nerve . To external rectus. f Connecting branches 7. Snventh nerve, or facial -( Branches for L distribution S. Ei^'hth nerve, or auditory f Connecting' branches Ninth nerve, or glosso- ' pharyngeal . . . j ' Connecting branches! 10. Tenth nerve, or pneumo- gastric 11. Eleventh nerve, or spinal accessory . • .j Branches for (^ distrlliUtioii ' Connecting branches 12. Twelfth nerve, lingual or ^ hypoglossal . Branches for \^ distribution To join auditory to Meckel's ganglion tympanic and sym- pathetic nerves the chorda tympani f Posterior auricular diirastric branch Btylo-hyoid branch ■\ temporo-facial . (^ cervlco-facial . To the portio dura rTol I ner l^ nerve ve to cochlea. to vestibule (Temporal malar infraorbital. r Buccal ,\ supramaxillary (inframaxillary. To the common sac to the saccule to the semicircular canals. B-anches for distribution To vagus to sympathetic. Jacobson's nerve ■ To carotid artery to the pharynx tonsillitic branches muscular lingual. To glosso-pharyngeal sympathetic and au- ricular nerves To the hypoglossal. • ("Pharyngeal nerve. Joins otic ganglion, supplies tympanum. ■I Branches for distiibution Connecting branchei superior laryngeal cardiac nerves. inferior laryngeal f External laryngeal ascending ^ to the \ , -.. { mucous .-j descending ^„e,„brane I to join the inferior lar- [ yngeal. Cardiac ocsophaireal, tracheal to constrictor and mus- es of larynx in superior laryn- geal. "I cle.« to joi L gea J To pneumo-gastric \ to the cervical plexus. < To sterno-mastoideus \ and trapezius. r To the pneumo-gas- ( trie nerve 4^ lo the sympathetic I to loop of atlas 1^ to gustatory nerve. ("descendens noni J thyro-hyoid nerve i to the lingual mus- ^_ clcB and tongue. SPINAL AND SYMPATHETIC NERVES, 223 TABLE OF THE SPINAL AND SYMPATHETIC NERVES OF THE HEAD AND NECK. Spinal Nerves. Superficial ascendiug /The first four form tlie Cervical / Plkxcs, which \ gives /Anterior branches ( superficial descending deep internal C Small occipital nerve < great auricular ( superficial cervical. £ Supraacromial < supraclavicular ( suprasternal. fTo the pneumo-gastric I to the hypoglossal -{ to the sympathetic I to join the spinal accessory I nerves to descendens noni. \deep muscular The cervical spinal / nerves ( divide \ into •1 posterior , branches To rectus muscles to diaphragm to the sterno-mastoideus to the trapezius to the levator anguli sch pulse. The rhomboid nerve r-Rvart^'haa oV./^»Ta I to the plirenic nerve The last four and ^ ,tn „io . f iL J suprascapular nerve part of first dor- ^^^ ciavicie . -i gu^clavian branch sal form the J | posterior thoracic Brachial j (^to the scaleni muscles. Plexus, which «i^«« • • • Lbranches below \ ^'it^jf;'"*''^ "^'^^ *^' "P^"' Are distributed to the muscles of the back, and give ofl" cuta- neous nerves. Sympathetic Nerve. ''Ascending branches, which unite in plexuses /I. Superior cervical ganglion > E 2. Middle cervical ganglion 3. Inferior cervical ganglion external branches Internal branches branches to vessels External branches i; nternal . f Anterior branches I external . internal . 'Carotid plexus, wh'ch gives Cavernous plexus, which gives branches . J to Branch to tympanic plexus the vidian the sixth and fifth cranial nerves. rTo the third cranial nerve I to the fourth cranial nerve J to the fifth and lenticular gang- 1 lion. to the carotid artery and I branches. !To join pneumo-ga'^trlc and hypoglossal nerves to tne spinal nerves, \ Pharyngeal branches ( superficial cardiac nerve. Nervl iTiolles. To the spinal nerves. I Middle cardiac nerve i to supply thyroid body and ( join the external laryngeal. To the subclavian artery. J To the spinal nerves forming ( vertebral plexus. Inferior cardiac norve. 224 DISSECTION OF THE UPPER LIMB. CHAPTEE in. DISSECTION OF THE UPPER LIMB. Section I. THE WALL OF THE THORAX AND THE AXILLA. The parts included in this section, viz., the wall of the chest and the axilla, are to be learnt within a fixed time, in order that the examination of the thorax may be undertaken. Whilst the dissection of the thorax is in progress, the student will have to discontinue his labors on the upper limb; but, on the completion of that cavity, he must be ready to begin the part of the Back that belongs to him. Position. Whilst the body lies on the Back, the thorax is to be raised to a convenient height by a block ; and the arm, being slightly rotated outwards, is to be placed at a right angle to the trunk. Directions. Before the dissection is entered on, attention should be given to the depressions on the surface, to the prominences of muscles, and to the projections of the bones ; because these serve as guides to the position of parts beneath the skin. Surface-marking. Between the arm and the chest is the hollow of the arm-pit, in wliich the large vessels and nerves of the limb are lodged. The extent of this hollow may be seen to vary much with the position of the limb to the trunk ; for in proportion as the arm is elevated, the fore and hinder boundaries are carried upwards and rendered tense, and the depth of the space is diminished. In this spot the skin is of a dark color, and is furnished with hairs and large sweat glands. If the arm is forcibly raised and moved in different directions, whilst the fingers of one hand are placed in the arm-pit, the head of the humerus may be recognized. On the outer side of tlie limb is the prominence of the shoulder ; and immediately above it is an osseous arch, which is formed internally by the clavicle, and externally by the spine and the acromion process of the scapula. Continued downwards from about the middle of the clavicle, is a slight depression between the pectoral and deltoid muscles, in which the coracoid process can be felt near that bone. A second groove, extending outwards from the sternal end of the clavicle, corresponds with the inter- val between the clavicular and sternal origin of the great pectoral muscle. Along the front of the arm is the prominence of the bice})S muscle ; and on each side of that eminence is a groove, which subsides inferiorly in a depression in front of the elbow-joint. The inner of the two grooves, the deepest, indicates the position of the brachial vessels. If the elbow joint be semiflexed, the prominences of the outer and inner condyles of the humerus will be rendered evident, especially the inner. PARTS ON FRONT OF THORAX. 225 Below the outer condyle, and separated from it by a slight interval, the head of the radius projects ; it may be recognized by rotating the bone, the fingers at the same time being placed over it. At the back of the articulation is the prominence of the olecranon. Dissection. As the first step in the dissection, raise the skin from the side of the chest and the arm-pit, over the great pectoral muscle and the hollow of the axilla, by means of the following incisions : — One is to be made along the middle of the sternum. A second, carried along the cla- vicle for the inner two-thirds of that bone, is to be continued down the front of the arm rather beyond the anterior fold of the arm-pit, and then to be turned across the inner surface of the arm as far as the hinder fold of the axilla. From the xiphoid cartilage a third cut is to be directed outwards over the side of the chest, as far back as to a level with the pos- terior fold of the arm-pit. The flap of skin now marked out should be reflected outwards beyond the axilla ; but it should be left attached to the body, in order that it may be used afterwards for the preservation of the part. The subcutaneous fatty layer of the thorax resembles the same structure in other parts of the body; but in this region it does not contain much fat. Beneath the subcutaneous layer is a deeper and stronger special fascia which closely invests the muscles, and is continuous with the deep fascia of the arm. It is thin on the side of the chest, but becomes much thicker where it is stretched across the axilla. An incision through it, over the arm-pit, will render evident its increased strength in this situation, and the casing it gives to the muscles bounding the axilla ; and if the fore finger be introduced through the opening, some idea will be gained of its capability of confining an abscess in that hollow. Dissection. The cutaneous nerves of the side of the chest are to be next sought. At the spots where they are to be found they are placed beneath the fat, so that the student must cut through it ; and those on the clavicle lie also beneath the platysma muscle. Small vessels will indicate the position of the nerves. Some of them (from the cervical plexus) cross the clavicle at the middle, and the inner part. Others (anterior cutaneous of the thorax) appear at the side of the sternum — one from each intercostal space. And the rest (lateral cutaneous of the thorax) should be looked for along the side of the chest, about one inch below the anterior fold of the axilla, there being one from each intercostal space except the first : as the last-mentioned nerves pierce the wall of the thorax, they divide into an anterior and a posterior piece. The posterior pieces of the highest two nerves are larger than the rest. They are to be followed across the arm-pit, and a junction is to be found there with a branch (nerve of Wrisberg) of the brachial plexus. Cutaneous nerves of the cervical plexus. These cross the clavicle and are distributed to the integuments over the pectoral muscle. The most internal branch (sternal) lies near the inner end of the bone, and reaches but a short distance below it. Other branches (clavicular), two or more in number and larger in size, cross the centre of the clavicle and extend to near the lower border of the pectoralis major ; they join one or more of the anterior cutaneous nerves of the thorax. The cutaneous nerves of the thorax are derived from the trunks of the intercostal nerves between the ribs (fig. 69). Of these there are two sets : One set, lateral cutaneous nerves of the thorax, arise from the 15 226 DISSECTION OF THE UPPER LIMB. trunks of the nerves about midway between the spine and the sternum. The other set, anterior cutaneous nerves of tlie tliorax, are the termina- tions of the same intercostal trunks at the middle line of the body. The anterior cutaneous nerves [)iercinji the pectoral muscle, are directed outwards in the integuments as slender filaments. The offset of the second nerve joins a cutaneous branch of the cervical plexus ; and the others supply the intejruments and the mammary gland. Small cutaneous branches of the internal mammary vessels accompany the nerves. The lateral cutaneous nerves (fig. G9) issue with companion vessels between the digitations of the seratus muscle, and divide into an anterior and a posterior piece. There is not usually any lateral cutaneous nerve to the first intercostal trunk. The anterior offsets {^) bend over the pectoral muscle, and end in the integuments and the mammary gland: they increase in size downwards, and the lowest give twigs to the digitations of the external oblique muscle. The cutaneous nerve of the second intercostal trunk wants commonly the antt^rior offset. The posterior offsets (®) end in the integuments over the latissimus dorsi muscle and the back of the scapula, and decrease in size from above down. The branch of the second intercostal nerve is larger than the rest, and perforates the fascia of the axilla ; it supplies the integument of the arm (p. 251), and is named intercosto-humeral. As it crosses the axilla it is divided into two or more pieces, and is connected to the nerve of Wris- berg (^) by a filament of variable size. The branch of the third intercostal gives filaments likewise to the arm- pit and the inner part of the arm. The MAMMA is the gland for the secretion of the milk, and is situate on the lateral aspect of the fore part of the chest.^ Resting on the great pectoral muscle, it is hemispherical in form, but it is rather most prominent at the inner and lower aspects. Its dimensions and weight vary greatly. In a breast not enlarged by lactation, the width is commonly about four inches. Longitudinally it extends from the third to the sixth or seventh rib, and transversely from the side of the sternum to the axilla. Its thickness is about one inch and a half. The weight of the mamma ranges from six to eight ounces. Nearly in the centre of the gland (rather to the inner side) rises the conical or cylindrical projection of the nipple or mamilla. This promi- nence is about half an inch or rather more in length, is slightly turned outwards, and presents in the centre a shallow depression, where it is rather redder. Around the nipple is a colored ring, — the areola, about an inch in width, whose tint is influenced by the complexion of the body, and is altered during the times of menstruation, pregnancy, and lactation. The skin of the nii)[)le and areola is {)rovided with numerous papillae and lubricating glands ; and on the surface are some small tubercles marking the position of the ducts of the glands. In the male the mammary gland resembles that of the female in general form, though it is less prominent; and it possesses a small nij)ple, which is surrounded by an areola provided with hairs. The glandular or secre- tory structure is imperfect. ' If the 8tufl body is a female, he may set aside the breast for a more con- venient examination of its structure. MAMMARY GLAND. 227 Structure. In its texture the mamma resembles those compound glands which are formed by the vesicular endings of branched ducts. It consists of small vesicles which are united to form lobules and lobes. Connected with each lobe is an excretory or lactiferous duct. A layer of areolar tissue, containing fat, surrounds the gland, and penetrates into the interior, subdiving it into lobes ; but in the ultimate structure of the gland, and in the nipple and areola, there is not any fatty substance. Some fibrous septa fix the gland to the skin, and support it ; these are the ligamenta suspensoria of Sir A. Cooper. Vesicles, The little vesicles or cells at the ends of the most minute ducts are rounded in shape, and when filled with milk or mercury are just visible to the naked eye, being about the size of a small pinliole in paper. (Cooper.) Each is surrounded externally by a close vascular network. Lobules and lobes. A collection of the vesicles around their ducts form the lobule or glandule, which varies in size from a pin's head to a small tare. By the union of the lobules the lobes are produced, of whicli there are about twenty altogether, and each is provided with a distinct duct. The duds issuing from the several lobes (about twenty) are named from their office galactophorus; they converge to the areola, where they swell into oblong dilations or reservoirs (sacculi) of one-sixth to one-third of an inch in width. Onwards from that spot the ducts become straight ; and, surrounded by areolar tissue and vessels, are continued through the nipple, nearly parallel to one another, and gradually narrowing in size, to open on the summit by apertures varying from the size of a bristle to that of a common pin. Like many other excretory ducts, the milk tubes consist of an external or fibrous, and of an internal or mucous coat ; they and the vesicles are sheathed by a columnar epitlielium, which becomes flattened towards the outer opening. Beneath the skin of the nipple and areola- are branched lubricating glands, which open on the tubercles before mentioned. Bloodvefiseh. — The arteries are supplied by the axillary, internal mammary, and intercostal, and enter both surfaces of the gland. The veins end principally in the axillary and internal mammary trunks ; but others enter the intercostal veins. The nerves are supplied from the anterior and lateral cutaneous branches of the thorax, viz., from the third, fourth, and fifth intercostal nerves. The lymphatics of the inner side open into the anterior mediastinal glands ; but on the outer side they reach the axillary glands. Dissection (fig. 69). With the limb in the same position to the trunk, the student is first to remove the fascia and the fat from the surface of the great pectoral muscle. In cleaning the muscle the scalpel should be car- ried in the direction of the fibres, viz., from the arm to thorax ; and the dissection may be begun at the lower border on the right side, and at the upper border on the left side. The fascia and tlie fat are to be taken from the axilla, without injury to the numerous vessels, nerves, and glands in the space. The dissection will be best executed by cleaning first the large axillary vessels at the outer part, where these are about to enter the arm : and then following their branches which are directed to the chest, viz., the long thoracic under cover of the anterior boundary, and the circumflex and subscapular vessels and nerves along the posterior boundary. Some arterial twigs entering the axillary glands should be traced out. In taking away the fascia and fat from the muscles in the posterior 228 DISSECTION OF THE UPPER LIMB. boundary of the space, the small internal cutaneous nerve of the musculo- spiral should be looked for near the great vessels. The large nerves of the brachial plexus are then to be defined. The smallest of these, which possibly may be destroyed, is the nerve of Wris- berg : it lies close to the hinder edge of the axillary vein, and joins with the intercosto-humeral nerve. When cleaning the serratus muscle on the ribs the student is to seek on its surface the posterior thoracic nerve ; and to trace the posterior off- sets of the intercostal nerves crossing the axilla. THE AXILLA. The axilla is the hollow between the arm and the chest (fig. 69). It is somewhat pyramidal in form, and its apex is directed upwards to the root of the neck. The space is larger near the thorax than at the arm, and its boundaries are as follows : — Boundaries. In front and behind the space is limited by folds, which are constructed by the muscles passing from the trunk to the upper limb. In the anterior fold are the two pectoral muscles, but these take unequal shares in its construction, in consequence of the difference in their size and shape : — thus the pectoralis major a extends over the whole front of the space, reaching from the clavicle to the lower edge of the anterior fold ; whilst the pectoralis minor b, which is a narrow muscle, corresponds only with the middle third of the space. In the posterior boundary, from above down- wards, lie the subscapularis f, the latissimus dorsi muscle d, and the teres major e : this boundary reaches further out than the anterior, especially near the humerus ; and its lower margin, which is formed by the latissimus dorsi, projects forwards beyond the level of the subscapularis. On the inner side of the axilla lie the first four ribs, with their inter- vening intercostal muscles, and the part of the serratus magnus c taking origin from those bones. On the outer side the space has but small di- mensions, and is limited by the humerus and the coraco-brachialis and biceps muscles (g and ii). The apex of the hollow is situate between the clavicle, the upper mar- gin of the scapula, and the first rib; and the forefinger may be introduced into the space for the purpose of ascertaining the upper boundaries, and the depth. The base or widest part of the pyramid is turned downwards, and is closed by the thick aponeurosis reaching from the anterior to the posterior fold. Contents of the space. In the axilla are contained the axillary vessels and the brachial plexus, with their branches ; some branches of tlie inter- costal nerves ; together with lymphatic glands, and a large quantity of loose areolar tissue and fat. Position of the trunks of vessels and nerves. The large axillary artery (a) and vein {b) cross the outer portion of the space in passing from the neck to the upper limb. The part of each vessel now seen lies close to the humerus, reaching beyond tlie line of the anterior fold of the arm-pit, and is covered only by the common superficial coverings, viz., the skin, the fatty layer or sui)erficial fascia, and the deep fascia. Behind the vessels are tlie subscapularis (k) and the tendons of the latissimus and teres muscles (d and e). To their outer side is the coraco-brachialis muscle (g). BOUNDARIES OF AXILLA, 229 On looking into the space from below, the axillary vein (b) lies on the thoracic side of the artery. After the vein has been drawn aside, the artery will be seen amongst the large nerves of the upper limb, having the median trunk (^) to the outside, and the ulnar (^) and the small nerve of Wrisberg (^) to the inner side ; the internal cutaneous (^) generally superficial to, and the musculo- spiral (*) and circumflex nerves beneath it. This part of the artery gives branches to the side of the chest and the shoulder. The vein receives some branches in this spot. Fig. 69. View of the DrasECXED Axilla (Illustrations of Dissections). Muscles : Nerves : A. Pectoralis major. 1. Median. B. Pectoralis minor. 2. Internal cutaneous. c. Serratus magnus. 3. Ulnar. D. Lastissimus dorsi. 4. Musculo-spiral. E. Teres major. 6. Nerve of Wrisberg. F. Subscapularis. 6 Internal cutaneous of musculo-spiral. o, Coraco-brachialis 7. Subscapular, H. Biceps. 8. Posterior pieces of the lateral cutaneous of Vessels : the thorax. a. Axillary artery. 9. Anterior pieces of cutaneous of the thorax. b. Axillary vein. c. Subscapular vein. d. Subscapular artery. e. Posterior circumflex artery. Position of the branches of vessels and nerves. The several branches of the vessels and nerves have the undermentioned position with respect to the boundaries : — Close to the anterior fold, and concealed by it, the long thoracic 230 DISSECTION OF THE UPPER LIMB. artery runs to the side of the chest ; and taking the same direction, though nearer the middle of the hollow, are the small external mammary artery and vein. Extending along the posterior fold, within its lower margin and in con- tact with the edge of the subscapularis muscle, are the subsca[)uhir vessels and nerves {d and ') ; and near the humeral end of the subscapularis the posterior circumflex vessels and nerve (e) bend backwards beneath the large axillary trunks. On the inner boundary, at the upper part, are a few small branches of the superior thoracic artery, which ramify on the serratus muscle; but these are commonly so unimportant, that this part of the axillary space may be considered free from vessels with respect to any surgical operation. Lying on the surface of the serratus magnus, is the nerve to that muscle ; and perforating the inner boundary of the space, are the lateral cutaneous nerves of the thorax — two or more offsets of whicli are directed across the axilla to the arm, and receive the name intercosto-humeral. The lymphatic glands of the axilla are arranged in two sets : one is placed along the inner side of the bloodvessels ; and the other occupies the lower and hinder parts of the space, l;^ing near and along the posterior boundary. Commonly they are ten or twelve in number; but in number and size they vary much. Small vascular twigs from the brandies of the axillary vessels are furnished to them. The glands by the side of the bloodvessels receive the lym|)hatics of the arm ; and those along the hinder boundary are joined by the lymphatics of the fore part of the thorax and posterior surface of the Back, as well as by some from the mamma. Most of the eflTerent ducts unite to form a trunk, which opens into the lymphatic duct of the neck of the same side ; some may enter separately the subclavian vein. The PECTORALis MAJOR, A, is triangular in shape, with the base at the thorax and the apex at the arm. It arises internally from tiie front of the sternum, and the cartilages of the true ribs except the last ; superiorly from the sternal half of the clavicle ; and inferiorly from the aponeurosis of the external oblique muscle of the abdomen. From this wide origin the fibres take different directions — those from the clavicle being inclined obliquely downwards, and those from the lower ribs upwards beneath the former ; and all end in a tendon, which is inserted into the outer edge of the bicipital groove of the liumerus for about two inches. This muscle bounds the axilla anteriorly, and is connected sometimes to its fellow by fibres in front of the sternum. Besides the su{>erficijd structures and the mamma, the platysma covers the pectoralis major close below the clavicle. A lengthened interval, which corresponds with a de- j)ression on the surface, se{)arates the clavicular from the sternal attach- ment. One border (outer) is in contact with the deltoid muscle, and with the cephalic vein and a small artery ; and the lower border forms the margin of the anterior fold of the axilla. The parts covered by the muscle will be seen subsequently. Action. If the humerus is hanging, the muscle will move forwards the limb until the elbow reaches the front of the trunk, and will rotate it in. When the limb is raised, the pectoralis depresses and adducts it ; and acting with other muscles inserted into tlie oj^posite side of the humerus, it may dislocate the head of that bone when the lower end is fixed, as in a fall on the elbow. PECTORALIS MINOR MUSCLE. 231 Supposing both limbs fixed as in climbing, the trunk will be raised by both muscles ; and the ribs can be elevated in laborious breathing. Dissection (fig. 70). The great pectoral muscle is to be cut across now in the following manner : — Only the clavicular part is to be first divided, so that the branches of the nerve and artery to the muscle may be found. Reflect the cut part of muscle, and press tlie limb against the edge of the table, for the purpose of raising the clavicle and rendering tight the fascia attached to that bone ; on carefully removing the fat, and a piece of fascia prolonged from the upper border of the small pectoral muscle, the membranous costo- coracoid sheath will be seen close to the clavicle, covering the axillary vessels and nerves. At this stage the cephalic vein is to be defined as it crosses inwards to the axillary vein. A branch of nerve (anterior thoracic), and the acro- mial thoracic artery, which perforate the tube of membrane around the vessels, are to be followed to the pectoral muscles. The remaining part of the pectoralis major may be cut about its centre, and the pieces may be thrown inwards and outwards. Any fat coming into view is to be removed ; and the insertion of the tendon of the pecto- ralis is to be followed to the humerus. Insertion of the pectoralis. The tendon of the pectoralis consists of two parts, anterior and posterior, at its attachment to the bone ; the ante- rior receives the clavicular and upper sternal fibres, and joins the tendon of the deltoid muscle ; and the posterior gives attachment to the lower ascending fibres. The tendon is from two inches to two inches and a half wide, and sends upwards one expansion over the bicipital groove to the capsule of the shoulder-joint, and another to the fascia of the arm. Parts covered by the pectoralis. The great pectoral muscle covers the pectoralis minor, and forms alone, above and below that muscle, the ante- rior boundary of the axilla. Between the pectoralis minor and the clavicle it conceals the subclavius muscle, the sheath containing the axillary ves- sels, and the branches perforating that sheath. Below the pectoralis minor it lies on the side of the chest, on the axillary vessels and nerves, and on the biceps and coraco-brachialis muscles near the humerus. The PECTORALIS MINOR (fig. 70, ^) rescmbles the preceding muscle in shape, and is extended like it from the thorax to the arm. Its origin is connected by slips with the third, fourth, and fifth ribs, external to their cartilages ; and between the ribs, with the aponeurosis covering the inter- costal muscles. The fibres converge to their insertion in the anterior half of the upper surface of the coracoid process of the scapula. This muscle is placed before the axillary space, and assists the pecto- ralis major in forming the middle of the anterior boundary: in that po- sition it conceals the axillary vessels and the accompanying nerves. The upper border lies near the clavicle, but between it and that bone is an in- terval of a somewhat triangular form. The lower border projects beyond the pectoralis major, close to the chest ; and along it the long thoracic artery lies. The tendon of insertion is united with the short head of the biceps and the coraco-brachialis. Action. Acting with the serratus magnus it moves the scapula for- wards and somewhat downwards. In laborious breathing it becomes an inspiratory muscle, as it takes its fixed point at the scapula. 232 DISSECTION OF THE UPPER LIMB. Dissection. Supposing the clavicle raised by the pressing backwards the arm, as before directed, the tube of fascia around the vessels will be demonstrated by making a transverse cut in the costo-coracoid membrane near the clavicle, so that the handle of the scalpel can be passed beneath it. By raising the lower border of the subclavius this muscle will be seen to be incased by fascia, which is attached to the bone both before and be- hind it. The costo-coracoid membrane, or ligament (fig. 70), is a firm membra- nous band, which receives this name from its attachment on the one side to the rib, and on the other to the coracoid process of the scapula. Between those points it is inserted into the clavicle, inclosing the subclavius muscle ; and is joined by the piece of fascia that incases the small pectoral muscle. From its strength and position it gives protection to the vessels surrounded by their loose sheath. When traced downwards it is found to descend on the axillary vessels and nerves, joining externally the fascia on the coraco-brachialis muscle, and blending with the sheath of the axillary vessels beneath the small pectoral muscle. Its extent is not so great on the inner as on the outer side, for internally it reaches but a very short distance on the axillary vein. The sheath of the axillary vessels and nerves, E, is derived from the deep fascia of the neck, being prolonged from that on the scaleni muscles ; and resembles, in its form and office, the funnel-shaped tube of membrane surrounding the femoral vessels in the upper part of the thigh. It is strongest near the subclavius muscle, where the costo-coracoid band joins it. The anterior part of the tube is perforated by the cephalic vein (e), the acromial thoracic artery (a), and the anterior thoracic nerve ('). Dissection. After the costo-coracoid membrane has been examined, the remains of it are to be taken away ; and the subclavius muscle, and the axillary vessels and nerves with their branches, are to be carefully cleaned. The SUBCLAVIUS muscle (fig. 70, ^) is roundish in form, and is placed between the clavicle and the rib. It arises by a tendon from the first rib, at the junction of the osseous and cartilaginous parts, and in front of the costo-clavicular ligament. The fibres ascend obliquely, and are inserted into a groove on the under surface of the clavicle, which reaches between the two tubercles (internal and external) for the attachment of the costo and coraco-clavicular ligaments. The muscle overhangs the large vessels and nerves of the limb, and is inclosed, as before said, in a sheath of fascia. Action. It depresses the clavicle, and indirectly the scapula ; but if the shoulder is fixed it elevates the first rib. The AXILLARY ARTERY (fig. 70) continucs the subclavian trunk to the upper limb. The part of the vessel to which this name is applied is con- tained in the axilla, and extends from the lower border of the first rib to the lower edge of the teres major muscle (h). In the axillary space its position will be marked by a line from the middle of the clavicle to the inner edge of the coraco-brachialis. Its di- rection will vary with the position of the limb to the trunk ; for when the arm lies by the side of the body the vessel is curved, its convexity being upwards ; and in proportion as the limb is removed to a right angle with the chest, the artery becomes straight. In the upper part of the axilla the vessel is deeply placed, but it becomes superficial as it approaches tiie arm. AXILLARY ARTERY 233 Its connections with surrounding parts are numerous ; and the descrip- tion of these will be methodized by dividing the artery into three parts one above, one beneath, and one below the small pectoral muscle. Above the small pectoral muscle the artery is contained in the axillary sheath of membrane, e. This part is concealed by the clavicular portion of the great pectoral muscle. Behind it are the intercostal muscles of the first space and the first digitation of the serratus magnus. Fig. 70. Second View of the Dissection of the Thorax (Illustrations of Dissections). MuscJes : Vessels : A. Pectoralis major, cut. a. Acromial-thoracic branch. B. Pectoralis minor. 6. Long thoracic branch. Serratus magnus. c. Subscapular branch. Subclavius. d. Axillary artery. Axillary sheath. e. Cephalic vein. Subscapularis. /. Brachial veins joining the axillary veins, g. Nerves : c. D. E. P. G. Latissimus dorsl. H. Teres major. J. Coraco-trachialis. K. Biceps. 1 and 2. Anterior thoracic branches. 3. Subscapular branch. 4. Nerve to the serratus. 5. Intercosto-humeral branch. To the thoracic side is placed the axillary vein (^). The cephalic vein (e), and offsets of the acromial thoracic artery and vein, cross over it. On the acromial side lie the two cords of the brachial plexus, separated from the vessel by a slight interval. Superficial to it lies an anterior tho- racic nerve ; and beneath, is the posterior thoracic. Beneath the pectoralis, the pectoralis minor and major b and A are superficial to the axillary vessel. But there is not any muscle immediately 234 DISSECTION OF THE UPPER LIMB. in contact behind, for the artery is placed across the top of the axilla, particularly when the limb is in the position required by the dissection. The companion vein (g) lies to the inner side, but separated from the arterial trunk by a bundle of nerves. In this position the cords of the brachial plexus lie around it, one being outside, a second inside, and a third beneath the artery. Beyond the pectoralis minor the artery is concealed in part by the lower border of the great pectoral muscle a, but thence to its termination it is covered only by the integuments and the fascia. Beneath it are the sub- scapularis muscle, f, and the tendons of the latissimus and teres, G and h. To the outer side is the coraco-brachialis muscle, J. The axillary vein remains as above on the thoracic side of the artery. Here the artery lies in the midst of the large trunks of nerves into which the brachial plexus has been resolved : On the outer side is the median nerve, with the musculo-cutaneous for a short distance; and on the inner side are the ulnar, and the nerve of Wrisberg. Superficial to the vessel is the internal cutaneous; and behind are the musculo-spiral and circumflex nerves, the latter extending only as far as the border of the subscapular muscle. The branches of the axillary artery are furnished to the wall of the thorax and the shoulder. The thoracic branches are four in number ; two (superior and acromial thoracic) arise from the artery above the pectoralis minor; one (alar thoracic) beneath the muscle; and one (long thoracic) at the lower border. Three branches are supplied to the shoulder, viz., subscapular and two circumflex ; the first springs opposite the edge of the muscle of the same name, and the others wind round the neck of the humerus. The last offsets are the external mammary and some muscular twigs. The superior thoracic branch is the highest and smallest offset, and arises opposite the first intercostal space; it ramifies on the side of the chest, anastomosing with the intercostal arteries. The acromial thoracic branch (fig. 70, a) is a short trunk on the front of the artery, which appears at the upper border of the pectoralis minor, and opposite the interval between the large pectoral and deltoid muscles. Its branches are directed inwards, outwards, and upwards : — a. The inner set supply the thoracic muscles, and give a few offsets to the side of the chest to anastomose with the intercostal and other thoracic arteries. h. The outer or acromial set end mostly in the deltoid; but one small artery accompanies the cephalic vein for a short distance ; and another {inferior acromial) perforates the deltoid muscle, and anastomoses on the acromion with a branch of the suprascapular artery of the neck. c. One or two small twigs ascend to the subclavius and deltoid muscles. The alar thoracic is very inconstant as a separate branch, and its place is taken by offsets of the subscapular and long thoracic arteries; it is dis- tributed to the glands and fat of the axillary space. The long thoracic branch is directed along the border of the pectoralis minor (fig. 70, h) to about the sixth intercostal space ; it supplies the pec- toral and serratus muscles, and anastomoses, like the other branches, with the intercostal and thoracic arteries. In the female it gives branches to the mammary gland. An external mammary artery is commonly met with, especially in the female; its position is near the middle of the axilla with a companion vein. BRACHIAL PLEXUS. 235 It supplies the glands, and ends in the wall of the thorax below tlie pre- ceding. Tl»e subscapular branch (fig. 70, c) courses with a nerve of the same name along the subscapularis, as far as the lower angle of the scapula, where it ends in branches for the serratus magnus, and the latissimus dorsi and teres muscles: it gives many offsets to the glands of the space. Near its origin the artery sends backwards a considerable dorsal branch round the edge of the subscapular muscle: this gives an infrascapular offset to the ventral aspect of the scapula, and then turns to the dorsum of that bone, where it will be afterwards dissected. The subscapular artery is frequently combined at its origin with other branches of the axillary, or with branches of the brachial artery. The circumflex branches (anterior and posterior) arise near the border of the subscapular muscle. One turns in front of, and the other behind the humerus. They will be followed in the examination of the arm. Small muscular offsets enter the coraco-brachialis muscle. The AXILLARY VEIN {g) continues upwards the basilic vein of the arm and has the same extent and connections as the axillary artery. It lies to the thoracic side of its artery, and receives thoracic and shoulder branches. Opposite the subscapular muscle it is joined externally by a large vein, which is formed by the union of the vense comites of the brachial artery; and near the clavicle the cephalic vein opens into it. Dissection. To follow out the branches of the brachial plexus, cut through the pectoralis minor near its insertion into the coracoid process, and turn it towards the chest, but without injuring the thoracic nerves in contact with it. The axillary vessels are next to be cut across below the second rib,^ and to be drawn down with hooks; and their thoracic branches may be removed at the same time. A dense fascia is to be cleared away from the large nerves of the plexus. The BRACHIAL PLEXUS results from the union of the anterior branches of the four lower cervical nerves with the first dorsal (in part) ; and a slip is added to it above from the lowest nerve in the cervical plexus. It is placed partly in the neck, and partly in the axilla, and is divided opposite the coracoid process into large trunks for the supply of the limb. The part of the plexus above the clavicle is described in the dissection of the head and neck (p. 79). The part below the clavicle has the same connec- tions with the surrounding muscles as the axillary artery. The nerve trunks interlace in it generally in the following manner: — At first the plexus consists of two bundles of nerves, which lie on the outer side of the artery, and are thus constituted ; — the one nearest the vessel is formed by the last cervical with the part of the first dorsal nerve; and the other, by the fifth, sixth, and seventh cervical nerves. A little lower down a third or posterior cord is produced by the union of two fas- ciculi, one .from each of the other bundles ; so that, beneath the small pec- toral muscle, the plexus consists of three large cords, one being on the outer side, another on the inner side, and the third behind the vessel. Occasionally there may be some d(;viation from the above mentioned arrangement. The branches of the plexus below the clavicles arise from the several cords in the following way : — ' The student must be careful not to cut the vessels higher than the spot men- tioned, otherwise he Mill injure the dissection of the neck. 236 DISSECTION OF THE UPPER LIMB. The outer cord gives origin to one anterior thoracic branch, the musculo- cutaneous trunk, and the outer head of the median nerve. The inner cord produces a second anterior thoracic nerve, the inner head of the median, the internal cutaneous, the nerve of Wrisberg, and the ulnar nerve. The posterior cord furnishes the subscapular branches, and ends in the circumflex and musculo-spiral trunks. Only the thoracic and subscapular nerves are dissected to their termina* tion at present ; the remaining nerves will be seen in the arm. The anterior thoracic branches (fig. 70, ^ and ^), two in number, are named outer and inner, like the cords from which they come. The outer nerve crosses inwards over the axillary artery, to the under surface of the great pectoral muscle in which it ends. On the inner side of the vessel it communicates with the following branch. The inner thoracic branch turns upwards between the artery and vein, and after receiving the offsets from the other, ends in many branches to the under surface of the pectoralis minor. Some twigs enter the great pectoral muscle, after passing either through tlie pectoralis minor or above its border. The subscapular nerves are three in number, and take their names from the muscles supplied : — The branch of the subscapularis is the highest and smallest, and enters the upper part of that muscle. The nerve of the teres major gives a small offset to the inferior part of the subscapularis, and ends in its muscle. A long nerve of the latissimus dorsi (•'') takes the course of the sub- scapular artery along the posterior wall of the axilla, and enters the fleshy fibres near the outer end. Another small nerve, nerve to the serratus (*) (posterior thoracic), lies on the surface of the serratus muscle. It arises above the clavicle (p. 80), from the fifth and sixth cervical nerves ; it descends behind the axil- lary artery, and enters that surface of the serratus magnus which is turned towards the axilla. The LATISSIMUS DORSI MUSCLE, G, may be examined as far as it enters into the posterior fold of the axilla. Arising from the spinal column and the back of the trunk, and crossing the lower angle of the scapula, the muscle ascends to be inserted into the bottom of the bicipital groove by a tendon, one inch and a half in width, in front of the teres ; at the lower border aponeurotic fibres connect the two, but a bursa intervenes between them near the insertion. Dissection. To lay bare the serratus muscle between the side of the chest and the base of the scapula, the arm is to be drawn from the trunk, so as to separate the scapula from the thorax. Tlie nerves of the brachial plexus may be cut through opposite the third rib ; and the fat and fascia should be cleaned from the muscular fibres. The SERKATUS MAGNUS MUSCLE (fig. 71, a) cxteuds between the scapula and the thorax. It arises by nine pointed processes from the outer surface of the eight upper ribs, — the second rib having two pieces ; and between the ribs it takes origin from the aponeurosis covering the inter- costal muscles. The fibres converge towards the base and angles of the scapula, but from a difference in their direction the muscle appears to consist of three parts. The upper part is attached internally to the first two ribs and an INTERCOSTAL MUSCLES 237 aponeurotic arch between tliem ; and externally, to an impression on the ventral surface of the upper angle of the scapula. A middle part, which is very thin, extends from the second, third, and fourth ribs, to the base of the shoulder bone. And a lower part, which is the strongest, is con- nected on the one side with four ribs (fifth, sixth, seventh, and eighth), where it digitates with like processes of origin of the external oblique muscle ; and, on the other side, it is fixed into the special surface on the costal aspect of the lower angle of the scapula. The serratus is applied against the ribs and the intercostal muscles, and is partly concealed by the pectoral muscles and the axillary vessels and nerves : in the ordinary position of the arm the scapula and subscapularis are in contact with it. Action. The whole muscle acting, the scapula is carried forwards. But the lower and stronger fibres can move forwards the lower angle, rotating the bone around an axis through the centre, and raise the acromion. Dissection. The intercostal muscles will be brought into view by de- taching the processes of origin of the serratus from the ribs for a couple of inches, and by taking away the loose tissue on the surface. Towards the front of the chest is a thin aponeurosis, which is continued forwards from each external intercostal to the sternum ; this is to be retained in the third intercostal space. Some of the lateral cutaneous nerves should be preserved. The INTERCOSTAL MUSCLES are named from their position between the ribs. There are two layers in each space, but neither occupies the whole length of the space. Tlie direction of the fibres differs in each stratum ; for, whilst the fibres of the external muscle run very obliquely down- Fig- 71. wards and forwards, those of the internal have an opposite direction between the osseous parts of the ribs, so that the two sets cross. The external muscle is fixed to the outer margin of the ribs of each intercostal space, and consists of fleshy and tendinous fibres. Pos- teriorly the fibres begin at or near the tubercle of tlie rib ; and ante- riorly they end short of the middle line, but after a different manner in the upper and lower spaces : — In the intervals between the true ribs, they cease near the costal cartilages, and a thin aponeurosis is continued onwards from the point of ending to the sternum. In the lower spaces they are continued between the car- tilages (Theile) reaching the end of the ribs in the last two. Dissection. The internal inter- costal muscle will be seen by cutting through and removing the external layer and the fascia in one of the Avidest spaces, say the second ; it will be recognized by the difference in the direction of the fibres. Far back between the two muscles, and close to the rib above, the inter- Diagram of the Serratus Maqnds Muscle. A. Attachmeuts. 238 DISSECTION OF THE UPPER LIMB. costal nerve and artery will appear. A branch of the nerve to the surface (lateral cutaneous of the thorax) should be followed througli the external muscle ; and the trunk of the nerve is to be traced forwards in one or more spaces to the sternum, and the surface of the thorax. The hinder part of these muscles will be seen in the dissection of the Back and thorax. The internal intercostal muscle, attached to the inner border of the ribs bounding the intercostal space, begins in front at the extremity of tlie ribs, and ceases behind near their angles. Posteriorly they do not end at the same distance from the spine, for the upper and lower approach nearer than the middle ; and, anteriorly, in the two lowest spaces, the muscular fibres are continuous with the internal oblique of the abdomen. One sur- face is covered by the external muscle and in part by the intercostal ves- sels and nerve ; and the opjjosite surface is in contact with the pleura. Action. By the alternate action of the intercostal muscles the ribs are moved in respiration. The external intercostals elevate the ribs and evert the lower edges, so as to enlarge the thorax in tlie antero-posterior and transverse directions : they come into play during inspiration. The internal intercostals act in a different way at the side and fore part of the chest. Between the osseous parts of the ribs they dej)ress and turn in those bones, diminishing the size of the thorax ; and th(y are brought into use in expiration. Between the rib-cartilages they raise the ribs, and become muscles of inspiration like the outer layer. If both stt.s of muscles contract simultaneously, the motion of the ribs will be arrested ; or if two or more ribs are broken near the spinal column, the muscles of the space or spaces injured will be unable to move these bones. Dissection. To bring into view the triangularis sterni muscle and the internal mammary vessels, the cartilages of the true ribs, except the first and seventh, are to be taken away with the intervening njuscles on the right side of the body ;^ but the two ribs menti )ned are to be left un- touched for the benefit of the dissectors of the abdomen and head and neck. Small arteries to each intercostal space and the surface of the thorax, and the intercostal nerves, are to be preserved. The surface of the triangularis sterni will be apparent when the loose tissue and fat are removed. The TRIANGULARIS STERNI (fig. 72, a) is a thin muscle beneath the costal cartilages. It arises internally from the side of tlie xiphoid carti- lage, from the side of the sternum as high as the third costal cartilage, and usually from the inner ends of the lower three true costjil cartilages. Its fibres are directed outwards, the upper being most oblique, and are inserted by fleshy fasciculi into the true ribs ex{;ept the last two and the first, at the junction of the bone and cartilage, and into an aponeurosis in the intercostal sj)aces. Tiie muscle is covered by the ribs and the internal intercostals, and by the internal mammary vessels and the intercostal nerves. It lies on the pleura. Its lower fibres touch those of the trans versalis abdominis. » On the left side the vessels and the muscle will have been destroyed by the injection of the body. INTERNAL MAMMARY VESSELS, 239 Action. The muscle assists in depressing the anterior ends of tlie ribs ; and by diminishing the size of the thorax, it becomes an expiratory muscle. The internal mammary artery is a branch of the subclavian (p. 77), and enters the thorax beneath the cartilage of the first rib. It is con- tinued through the thorax, lying beneath the costal cartilages and about half an inch from the sternum, as far as the interval between the sixth and seventh ribs; there it gives externally a large muscular branch (musculo-phrenic), and passing beneath the seventh rib, enters the sheath of the rectus muscle in the wall of the abdomen. In the chest the artery lies on the pleura and the triangularis sterni, and is crossed by the intercostal nerves. It is accompanied by two veins, and by a chain of lymphatic glands. The follow- ing branches take origin in the thorax : — a. A small branch {comes nervi phrenici) arises as soon as the artery enters the chest, and descends to the diaphragm along the phrenic nerve. h. A few small mediastinal branches are distributed to the remains of the thymus gland, the pericardium, and the tri- angularis sterni muscle. c. Two anterior intercostal branches turn outwards in each space, one being placed on the border of each costal cartilage, and terminate by anastomosing witli the aortic inter- costal arteries. . d. Perforating branches^ one or two opposite each space, pierce the in- ternal intercostal and pectoral muscles, and are distributed on the surface of the thorax with the anterior cutaneous nerves: the lower branches sup- ply the mamma in the female. e. The musculo-phrenic branch courses outwards beneath the cartilages of the seventh and eighth ribs, and enters the wall of the abdomen by perforating the diaphragm: it supplies anterior branches to the lower intercostal spaces. Its termination will appear in tiie dissection of the abdomen. Two veins accompany the artery; these join into one trunk, which opens into the innominate vein. The intercostal nerves, seen now in the anterior part of their extent, are the anterior primary branches of t;he dorsal nerves, and supply the wall of the thorax. Placed at first between the layers of the intercostal muscles, each gives off the lateral cutaneous nerve of the thorax, about midway between the spine and tlie sternum. Diminished in size by the emission of that offset, the trunk is continued onwards, at first in, and afterwards beneath the internal intercostal muscle as far as tlie side of the sternum, where it ends as the anterior cutaneous nerve of the thorax. Branches supply the intercostal muscles, and the triangularis sterni. View from behind of the Attachments of the Triangulakis Sterni Muscle, a. 240 DISSECTION OF THE UPPER LIMB. The aortic intercostal arteries lie with the nerves between the strata of intercostal muscles, and nearer the upper than the lower rib bounding the intercostal space. About the mid point of the space (from before back) the artery bifurcates: — one branch follows the line of the upper rib, and the other descends to the lower rib ; both anastomose anteriorly with the intercostal offsets of the internal mammary artery. A small cutaneous offset is distributed with the lateral cutaneous nerve of the thorax; and other branches are furnished to the thoracic wall. Directions. The dissector of the upper limb waits now the appointed time for the examination of the thorax. But as soon as the body is turned he is to take his share in the dissection of the Back, and to proceed with the parts marked for him in Chapter V. After the Back is finished the limb is to be detached from the trunk by sawing the clavicle about the middle, and cutting through the soft parts connected with the scapula. Section II. SCAPULAR MUSCLES, VESSELS, NERVES, AND LIGAMENTS. Position. After the limb has been separated from the trunk it is to be placed with the subscapularis uppermost. Dissection. The different muscles that have been traced to the scapula in the dissection of the front of the thorax and the Back, are now to be cleaned, and to be followed to their insertion into the bone. A small part of each, about an inch in length, should be left for the purpose of ascertaining the osseous attachment. Between the larger rhomboid muscle and the serratus magnus at the base of the scapula, run the posterior scapular artery and vein, whose ramifications are to be traced. To the borders and the angles of the scapula the following muscles are connected: — From the upper margin of the scapula arises one muscle, the omo-hyoid (fig. 73, e). At its origin that muscle is about half an inch wide; it is attached to the edge of the bone behind the notch, and sometimes to the ligament which converts the notch into a foramen. • The lower margin, or costa, gives origin to the long head of the triceps (fig. 79, a), and to some fibres of the teres major; but these attachments will be ascertained in the progress of the dissection. The base of the bone has many muscles inserted into it (fig. 74). Be- tween the superior angle and the spine is the levator anguli scapulye, h. Opposite the spine the rhomboideys minor, j, is fixed. And between the spine and the inferior angle the rhomboideus major, k, is attached: the upper fibres of this muscle end often in an aponeurotic arch, and are con- nected indirectly to the bone by means of an expansion from it. Internal to those muscles, and inserted into all the base of the scapula, is the ser- ratus magnus muscle (fig. 73, d). On the inner surface of the upper and lower angles of the scapula the SUBSCAPULARIS MUSCLE. 241 fibres of the serratus magnus are collected. On the outer surface of the inferior angle lies tlie teres major (fig. 79, g) which will be subsequently seen. The insertion of the small pectoral muscle into the fore part of the upper surface of the coracoid process may be ascertained at this stage of the dissection (tig. 73, f). • Fiff. 73. A. Subscapiilaris. B. Teres major. c. Latissimus dorsi. D. Serratus magnus. E. Omo-hyoideus. F. Pectoralis minor. G. Biceps. H. Coraco-brachialis. a. Supra-scapular artery. 1. Supra-scapular nerve passing through the notch. View of the Si-bscapiti.akis and the sprroundino Muscles. The other muscles fixed into the base of the scapula as shown in fig. 74. Dissection. By the separation of the seri-atus from the subscapularis a thin fascia comes into view, which belongs to the last muscle, and is fixed to the bone around its margins ; after it has been observed, it may be re- moved. The subscapularis muscle is to be followed forwards to its insertion into the humerus. Next, the axillary vessels and nerves, and the offsets of these to the muscles, should be well cleaned. The suBSCAPrLARis MUSCLE (fig. 73, a) occupies the under surface of the scapula, and is concealed by that bone when the limb is in its natural position. The muscle arises from the concave surface on the ventral aspect of the scapula, except at the angles, and this attachment reaches forwards nearly to the neck ; it is united also to tlie ridges of the bone by tendinous processes. Externally it is inserted by a tendon into the small tuberosity of tlie humerus, and by fleshy fibres into the neck for nearly an incli below that process. By one surface the muscle bounds the axilla, and is in contact with tlie axillary vessels and nerves and the serratus magnus. By the other, it rests against the scapula and the shoulder joint ; and between its tendon and the root of the coracoid process is a bursa, which communicates gene- rally with the synovial membrane of the joint. The lower border projects much beyond the bone ; it is contiguous to the teres major, the latissimus 16 242 DISSECTION OF THE UPPER LIMB. dorsi, and the long head of the triceps : along this border is the subscapular artery, which gives backwards its dorsal branch. Action. It rotates in the hanging limb ; and when the humerus is raised it depresses the bone. If the humerus is fixed the subscapularis supports the shoulder joint with the other scapular muscles. jyissection. The subsca[)ular muscle is to be separated from the scapula, but a thin layer of fibres, in which the vessels lie, is to be left on the bone : as it is raised its tendinous processes of origin, the connection between its tendon and the capsule of the shoulder joint, and the bursa, are to be ob- served. A small arterial anastomosis on the ventral surface of the bone is to be dissected out of the fleshy fibres. The infrascapular artery ramifies on the ventral surface of the scapula, and is an offset of the dorsal branch of the scapular vessel (p. 335): en- tering beneath the subscapularis muscle, it forms an anastomosis with small twigs of the supra and posterior scapular branches. Position. The examination of the muscles on the opposite surface of the scapula may be next undertaken. For this purpose the scapula is to be turned over ; and a block, which is deep enough to make tlie shoulder prominent, is to be placed between that bone and the arm. Dissection. The skin is to be removed from the prominence of the shoulder, by beginning at the anterior border of the deltoid muscle. After its removal some small cutaneous nerves are to be found in the fat: — the upper of these extend over the acromion ; and another comes to the sur- lace about half way down the posterior border of the deltoid muscle. Superjicial nerves. Branches of nerves, super- acromial^ descend to the surface of the shoulder from the cervical plexus (p. 66). A cutaneous branch of the circumflex nerve (fig. 74,'"') turns forwards with a small companion artery from beneath the posterior border of the deltoid, and supplies the integuments covering the lower two-thirds of the muscle. Dissection. The fat and fascia are now to be taken from the fleshy del- toid, its fibres being made tense at the same time. Beginning at the anterior edge of the muscle, the dissector is to carry the knife upwards and downwards along the fibres, in order that its coarse muscular fasciculi may bi more easily cleaned. As the posterior edge is approached, the cuta- neous nerve and artery escaping from beneath it, are to be dissected out. At the same time the fascia may be removed from the back of tiie scapula, so as to denude the muscles there. The DELTOID MUSCLE is triangular in form (fig. 74, ^), with the base at the scapula and clavicle, and the apex at the humerus. It arises from n;^arly all the lower edge of the spine of the scapula, from the anterior edge of the acromion, and from the outer half or third of the clavicle. Its fibres converge to a tendon, which is inserted into a triangular imjjression, two or three inches long and about one inch wide at the base, above the middle of the outer surface of the humerus. The anterior border is contiguous to the pectoralis major muscle and the, cephalic vein ; and the posterior rests on the infraspinatus and triceps muscles. The origin of the muscle corresponds with the attachment of the trapezius to the bones of the shoulder; the insertion is united witli the tendon of the pectoralis major, and a fasciculus of the brachialis amicus is attached on each side of it. Action The whole muscle raises the humerus, and abducts it from DELTOID MUSCLE, 243 the trunk. The linil) bein*^ rjiised, the anterior fibres will carry it for- Avards, and the posterior fibres will move it backwards. When the humerus is fixed as in climbing, the muscle assists in sup- porting the w^eight of the body, and strengtiiening the shoulder-joint. Dissection (fig. 74). The deltoid is to be divided near its origin, and is to be thrown down as much as the circumflex vessels and nerve beneath will permit. As the muscle is raised a large thick bursa between it and the head of the humerus comes into sight. The loose tissue and fat are to be taken away from the circumflex vessels and nerve ; and the size of the bursa having been looked to, the remains are to be removed. Tlie insertion of the muscle should be examined. Fiff. 74. ViKW OF THE MUSCLKS OF THE DORSUM OF THE SCAPCLA, AXD OF THE CiRCrMFI.EX VESSELS AXD Kerve. (Illustrations of Dissections.) Muscles: Arteries: A. Supra-sp'natus. a. Posterior circumflex artery. B. Infra-spinatus. b. Branch to teres minor. c. Teres minor. c. Dorsal scapular branch of sub- ». Teres major. scapular. E. Latissimus dorsi. Nerves : F. Deltoid. 1. Posterior circumflex. o. Triceps (long head). 2. Its cutaneous ofl"sot to the arm. H. Levator anguli scapula?. 3. Branch to the teres minor muscle. J. Rhomboideus minor. K. Rhomboideus m ijor. Parts covered hy deltoid. The deltoid conceals the head and upper end of the humerus, and those ])arts of the dorsal scapular muscles which are fixed to the great tuberosity. A large bursa, sometimes divided into sacs, intervenes between the head of the humerus and the under surface of tlie deltoid muscle and the acromion process. Below the head of the 244 DISSECTION OF THE UPPER LIMB. bone are the circumflex vessels and nerve, and the upper part of the biceps muscle. In front of the humerus is the coracoid process with its muscles. Dissection. By following back the posterior circumflex vessels and nerve through a space between the humerus and the long head of the tri- ceps, G, their connection with the axillary trunks will be arrived at. In clearing the fat from the space a branch of the nerve to the teres minor muscle is to be sought close to the border of the scapula, where it is sur- rounded by dense fibrous tissue. Arching outwards in front of the neck of the humerus, is the sm^U anterior circumflex artery : this is to be cleaned. The circumflex arteries arivSe near the termination of the axillary trunk (p. 335) ; they are two in number, and are named anterior and posterior from their position to the neck of the humerus. The anterior branch is a small artery, which courses beneath the coraco-brachialis and biceps muscles, and ascends in the bicipital groove to the articulation and the head of the humerus : it anastomoses with small offsets of the posterior circumflex. The posterior circumflex artery (fig. 74, «), larger in size, winds back- wards through a space between the humerus and the long head of the triceps, and is distributed chiefly to the deltoid muscle, in which it anasto- moses with the acromial thoracic and upper profunda arteries. Branches are given from it to the head of the humerus and the shoulder joint, and to anastomose with the anterior circumflex artery. It supplies branches likewise to the teres minor, the long head of the triceps, and the integuments. The circumflex nertw (fig. 74, ^) leaves the arm-pit with the posterior circumflex artery (p. 335), and bends round the neck of the humerus; beneath the deltoid muscle in which it ends. Many and large branches enter the deltoid, and terminate in it; one or two filaments pierce the fibres and become cutaneous. Branches. In the axilla it gives an articular filament to the under part of the shoulder-joint. Behind the humerus it furnishes an ofl^set to the teres minor (^), which has a reddiwsh gangliform swelling on it. And at the edge of the deltoid it gives origin to the cutaneous nerve (^) before noticed. The INFRASPINATUS MUSCLE (fig. 74, b) occupies the infraspinal part of the scapula, and extends to the head of the humerus. The muscle arises from the infraspinal fossa, except at three spots, viz., the neck, and the low^er angle and inferior border where the teres muscles are attached ; it arises also from the lower side of the spinous process, and from the special fascia covering the surface. Its fibres converge to a tendon, which is in- serted into the middle impression on the great tuberosity of the humerus, and joins the tendons of the supraspinatus and teres minor. A part of the muscle is subcutaneous, and the fibres arising from the spine of tlie scapula overlay the tendon : the upper portion is concealed by the deltoid ; and the lower end, by the latissimus dorsi. The lower border is f)arallel to tlie teres minor, with which it is sometimes united. The muscle lies on the scapula and the humero-scapular articulation, but between it and the joint is a small bursa. Action. With the humerus hanging it acts as a rotator outwards; and when the bone is raised it will move the same backwards in concert with the hinder part of the deltoid. DORSAL SCAPULAR MUSCLES. 245 The TERES MINOR (fig. 74, c) is a narrow fleshy slip, which is often united inseparably with the preceding muscle, along whose lower border it lies. It arises on the dorsum of tlie scapula from a special surface alono- the upper two-thirds of the inferior costa of the bone, and from the invest- ing fascia ; and it is inserted by a tendon into the lowest of the three marks on the great tuberosity of the humerus, as well as by fleshy fibres into the humerus below that spot — about an inch together. This muscle is partly covered by the deltoid ; it rests on the long head of the trice))S and the shoulder joint. Underneath it the dorsal branch of the subscapular artery turns. Action, The arm hanging the muscle rotates it out and moves it back ; the arm being raised the teres depresses the humerus. In climbing it sui)ports the joint like the preceding scapular muscles. The TERES MAJOR musclc (fig. 74, d) is extended from the inferior angle of the scapula to the humerus. Its origin is from the rough surface on tlie dorsum of the bone at the inferior angle ; from the inferior costa as far forwards as an inch from the long head of the triceps ; and from the fascia cov^ering the teres minor. The fibres end in a tendon which is inserted partly into, and partly behind the inner edge of the bicipital groove of the humerus. This muscle assists in forming the posterior fold of the axilla ; and is situate beneath the axillary vessels and nerves near the humerus (fig. 70). At its origin it is covered by the latissimus dorsi. The upper border is contiguous to the subscapularis muscle, and the lower is received into a hollow formed by the fibres of the latissimus dorsi At the humerus the tendon of the muscle is one inch and a half to two inches wide, and is placed behind that of the latissimus: the two are separated above by a bursa ; but they are united below, and an expansion is sent from them to the fascia of the arm. A second bursa lies between the tendon and the bone. Action. If the limb hangs it is carried back behind the trunk and is rotated inwards by the muscle. The humerus being raised, the muscle depresses and adducts it. With the limb fixed by the hand the teres will cause the lower angle of the scapula to move forwards. Below the scapula (inferior costa), where the teres muscles separate from one another, is a triangular interval, which is bounded in front by the shaft of the humerus, and above and below by the teres muscles. This space is divided into two by the long head of the triceps. Through the anterior part, which is of a quadrilateral shape, the posterior circumflex vessels and the circumflex nerve pass : and opposite the posterior trian- gular space, the dorsal branch (c) of the subscapular artery bends back- wards. Dissection (fig. 75). In order that the acromion process may be sawn through to expose the supraspinatus muscle, the ligaments of the scapula and clavicle, which would be injured by such a proceeding, should next be dissected. A ligament (coraco-clavicular) ascends from the coracoid process to the under part of the clavicle : on removing the areolar tissue it will be seen to consist of two parts, anterior and posterior, differing in size, and in the direction of the fibres. A capsular ligament, connecting the outer end of the clavicle with the acromion, will be recognized by taking away the fibres of the trapezius and deltoid muscles. 246 DISSECTION OF THE UPPER LIMB Another strong band (coraco-acromial) passing transversely between the acromion and the coracoid process ; and a small fasciculus (posterior proper ligament), placed over the notch in the superior costa, are then to be defined. , . Ligaments of the Clavicle anp Scapula (fig. 75). The clavicle is connected to the scapula by a distinct joint with the acromion, and by a strong ligament (coraco-clavicular) between it and the coracoid process. The coraco-clavicnlar ligament consists of two parts, each having a different direction and designation. The posterior piece (^), called conoid from its shape, is fixed by its apex to the posterior and inner part of the coracoid process ; and by its base to the tubercle and the contiguous part of the under surface of the clavicle, at the junction of the outer with the middle third of tlie bone. The anterior part (^), trapezoid ligament, is larger than the conoid piece : it is connected inferiorly to the inner border of the carocoid pro- cess along the hinder half; and superiorly to the line on the under surface of the clavicle which extends outwards Irom the tubercle before mentioned. The two pieces of the ligament ai*e in apposition posteriorly, but are sepa- rated by an interval in iront. Use. Both pieces of the ligament support the scapula in a state of rest : they serve also to restrain the rotatory movements of that bone ; thus Fig. 75. 1. Conoid lli?ament. 2. Trapezoid ligament. 3. Anteiior ligament of the scapnia. 4. Posterior scapular ligament. 5. Capsule of the shoulder joint. 6. Tendon of the long head of the bi- ceps entering the joint. 7. Tendon of the subscapular muscle. 8. Coraco humeral ligament. LlOAMEXTS OF THE Cl.AVICLE AND SCAPUI.A, AND OF THE SHOULDER JoiNT (altered from Bourgery and Jacob). when the acromion is rotated down, the motion is checked by the trapezoid band ; and when upwards, by the conoid piece. Acromio-clavicular articulation. The articular surfaces of the clavicle and acromion process of the scapula are retained in contact by a capsule formed of strong fibres. Some of the fibres are thicker above and below, and are considered to constitute a superior and an inferior ligament. An inter articular Jibro-cartilage generally exists at the upper part of the joint ; but sometimes it forms a complete interarticular septum. If the fibro-cartilage is perfect, there are two synoviol membranes {)resent in the joint ; if it is imperfect, there is only one. The joint should be opened to see the cartilage and the synovial membrane. Movements. In this articulation there are limited fore and back and up and down movements of the scapula. SCAPULAR LIGAMENTS. 247 Besides, there is a glidinjr movement of the acromion on the clavicle in rotation of the scapula. For instance, when the acromion is depressed, its articular surface moves from above down at the fore part of the joint, and from below up at the back. When the acromion is elevated the sur- iace moves in exactly the opposite way. Scapular Ligaments. The special ligaments of the scapula are two in number, anterior and posterior, and extend from one part of the bone to another. The posterior ligament (*) is a narrow fasciculus of fibres stretching across the notch in the upper costa of the scapula. By one end it is at- tached to the base of the coracoid process, and by the other to the costa behind the notch. It converts the notch into a foramen, through which the suprascapular nerve passes. The anterior or coraco-acromial ligament (') is triangular in form, and extends transversely between the acromion and the coracoid process. Ex- ternally it is inserted by its point or apex into the tip of the acromion ; and internally, where it is much wider, it is attached to all the outer border of the coracoid process, reaching backwards to the capsule of the shoulder joint. The ligament consists usually of two thickened bands, anterior and j)OSterior, witii a thin intervening part. It forms part of an arch above the shoulder joint, which stops the ascent of the head of the humerus. Dissection, To lay bare the supraspinatus muscle, the acromion pro- cess is to be sawn tlirough, and to be turned aside with the outer end of the clavicle : but in the repetition of the dissection of the upper limb, the bone may be left uncut for the purpose of seeing the use of the coraco- acromial arch. A strong fascia covers tlie surface of the muscle ; this is to be taken away after it has been observed. The SUPRASPINATUS MUSCLE (fig. 74, ^) has the same form as the hollow of the bone it fills. It arises from tlie surface of the supra-spinal fossa of the scapula, except from the cervical part ; from the upper side of the spine of the bone ; and from the fascia covering the surface. Its fibres end in a tendon, which crosses over tlie shoulder joint, and is inserted into the upper im[)ression of tlie great tuberosity of the humerus. The mui-cle is concealed by the trapezius and the acromion process ; and it rests upon the scaj)ula, the shoulder joint, and the suprascapular ves- sels and nerve. Its tendon joins that of the infraspinatus at the attach- ment to the humerus. Action. It comes into use with the deltoid in raising the limb, and supporting the joint. Dissection (fig. 78). The vessels and nerves on the dorsum of the scapula can be traced by detaching from beliind forwards the supra and infraspinatus muscles, so as to leave a thin layer of the fleshy fibres with the ramifying bloodvessels on the surface of tlie bone. In the supraspinal fossa are the suprascapular vessels and nerve, which are to be followed beneath the acromion to the intraspinal fossa ; and entering the infra- spinal fossa, beneath the teres minor muscle, is the dorsal branch of ti»e subscapular artery. The anastomosis between those vessels should be pur- sued in the fleshy fibres and cleaned. The suprascapular artery (a) is derived from the subclavian trunk, and is one of the branches of the thyroid axis (p. 78). After a siiort course in the neck it passes over the ligament at the superior costa, and crossing beneath the supraspinatus muscle, ends in the intraspinal fossa, 248 DISSECTION OF THE ARM. where it gives offsets to the infraspinatus muscle and the scapuhi, and anastomoses with the dorsal branch of the subscapular, and the posterior scapular artery of the subclavian. Beneath tlie suj)raspinatus it furnishes a supraspinal branch for the supply of the muscle, the bone, and the shoulder-joint. The companion vein of the suprascapular artery joins the external jugu- lar vein. The suprascapular nerve Q) is a branch of the brachial plexus (p. 80). When it reaches the costa of tlie scapula, it enters the supraspinal fossa beneath the posterior special ligament. In the fossa it supplies two branches to the supraspinatus ; and is continued beneath a fibrous band to the infraspinatus muscle, in which it ends. The nerve gives some articular filaments to the shoulder-joint, and other offsets to the scapula. Tlie posterior scapular artery runs along the base of the scapula beneath the rhomboid muscles, furnishing offsets to them and the surfaces of the bone. It is more fully noticed with the dissection of tlie Back. The dorsal branch of the subscapular artery (b) (p. 335) turns below the inferior costa of the scapula, opposite the posterior of the two spaces between the teres muscles. Entering the intraspinal fossa beneath the teres minor, it supplies that muscle and the infraspinatus, and communi- cates with the suprascapular artery. This vessel sends a branch along the dorsum of the scapula between the teres muscles, towards the inferior angle of the bone. Section III. THE FRONT OF THE ARM. Position. For the dissection of the superficial vessels and nerves on the front of the arm, the limb should lie flat on the table, with the front uppermost. Dissection. The skin is to be raised from the fore and hinder parts of the arm and elbow-joint. To reflect it, make one incision along the centre of the limb as far as two inches below the elbow ; and at the termination, a second cut half round the forearm. Strip now the skin from the limb, as low as the transverse incision, so that the fat which contains the cuta- neous vessels and nerves may be denuded. Between the skin and the prominence of the olecranon a bursa may be seen. The cutaneous veins (fig. 76) may be sought first in the fat: they are very numerous below the bend of the elbow, as they issue from beneath the integument. One in the centre of the forearm is the median vein, which bifurcates rather below the elbow. External to this is a small vein (radial) ; and internal to it are the anterior and posterior ulnar veins, coming from the front and back of the forearm. At the elbow these veins are united into two ; one (basilic) is to be followed along the inner side, and the other (cephalic) along the outer side of the arm. The cutaneous nerves may be next traced out. Where tliey perforate the deep fascia they lie beneath the fat ; and this layer must be scra[)ed through to find them. CUTANEOUS VEINS. 249 On the outer side of the arm, about its middle, two external cutaneous branches of the rausculo-spiral are to be sought. In the outer bicipital groove, in front of the elbow or rather below it, the cutaneous part of the musculo-cutaneous nerve will be recognized. On the inner part of the limb the nerves to the surface are more nume- rous. Taking the basilic vein as a guide, the internal cutaneous nerve of the forearm will be found by its side, about the middle of the arm ; and rather external to this nerve is a small cutaneous offset from it, which pierces the fascia higher up. Scrape through the fat behind the internal cutaneous, in the lower third of the arm, for the small nerve of Wrisberg ; and in the upper third, seek the small nerves which have been already met with in the dissection of the axilla, viz., the intercosto-humeral, and the internal cutaneous of the musculo-spiral. Superficial fascia. The subcutaneous fatty layer forms a continuous investment for the limb, but it is thicker in front of the elbow than in the other parts of the arm. In that spot it incloses the superficial vessels and the lymphatics. Cutaneous Veins. The position and the connections of the superficial veins in front of the elbow are to be attentively noted by the dissector, because the operation of venesection is practised in one of them. The median vein of the forearm (fig. 76, =*), divides into two branches, internal and external, rather below the bend of the elbow ; at its point of division it is joined by an offset from a deep vein. The internal branch (median basilic) crosses to the inner border of the biceps, and unites with the ulnar veins (^) to form the basilic vein of the inner side of the arm. The external branch (median cephalic) is usually longer than the other, and by its junction with the radial vein (J) gives rise to the cephalic vein of the arm. The connections of the two veins into which the median bifurcates, are described below : — The median cephalic vein (fig. 7G) is directed obliquely, and lies over the hollow between the biceps and the outer mass of muscles of the fore- arm. Beneath it is the trunk of the musculo-cutaneous nerve ; and over it some small offsets from the nerve are directed. This vein is altogether removed from the brachial artery, and is generally smaller than tlie me- dian basilic vein. If opened with a lancet, it does not generally yield much blood, in consequence of its position in a hollow between muscles rendering compression of it very uncertain and difficult. The median basilic vein (fig. 76, ^) is more horizontal in direction than the preceding, and crosses the brachial artery. It is larger than the cor- responding vein of the outer side of the arm, and is firmly supported by the underlying fascia — the aponeurosis of the arm, strengthened by fibres from the biceps tendon, intervening between it and the brachial vessels. Branches of the internal cutaneous nerve lie beneath it, and some twigs of the same nerve are placed over it. The median basilic is the vein on which the operation of blood-letting is commonly performed. It is selected in consequence of its usually larger size, and more superficial position, and of the ease with which it may be compressed ; but from its close proximity to the brachial vessels, the spot to be opened should not be immediately over the trunk of the artery. The basilic vein (fig. 76, ^), commencing as before said, ascends near the inner border of the biceps muscle to the middle of the arm, where it 250 DISSECTION OF THE ARM. passes beneath the deep fascia, and is continuous with the axillary vein. In this course it lies to the inner side of the brachial artery. The cephalic vein (fig. 76, ^) is derived chiefly from the external branch of the median, for the radial vein is oftentimes very small : it is continued to the shoulder along the outer side of the biceps, and sinks between the deltoid and pectoral muscles, near the clavicle, to open into the axillary vein. Fig. 7(J. 1. Median basilic vein. 2. Median vein of the forearm bifurcating. .3. Anterior ulnar veins. 4. Cephalic vein formed by radial from behind and the median cephalic in front. The musculo-cutaneous nerve is by the side of it. '). Basilic vein, with large internal cutaneous nerve by its side. 6. Brachial artery, with its companion veins (one cut). 7. Kadial vein. CcTAXEOus Veins and NsRVts at the Bend of the Elbow. (Quain's " Arteries.") The superficial lymphatics of the arm lie for the most part along the basilic vein, and enter into the glands of the axilla. A few lympliatics accompany the cephalic vein, and end as the others in the axillary glands. One or more superficial lymphatic glands are commonly found near the inner condyle of the humerus. Cutaneous Nerves. The superficial nerves of the arm appear on the inner and outer sides, and spread so as to cover the surface of the limb. With one exception (intercosto-humeral) all are derived from the brachial plexus, either as distinct branches, or as offsets of other nerves. On the outer side of the limb are branches of the musculo-sjiiral and musculo- cutaneous nerves. On the inner side are two internal cutaneous nerves, large and small (from the plexus), a third internal cutaneous from the musculo-spiral, and the intercosto-humeral nerve. External cutaneous Nerves. The external cutaneous branches of the musculo-spiral nerve are two in number, and appear at the outer side of the limb about the middle. The upper small one turns forwards with the cephalic vein, and reaches the front of the elbow, supplying the ante- rior part of the arm. The lower and larger pierces the fascia somewhat farther down, and after supplying some cutaneous filaments, is continued to the forearm. The cutaneous part of the musculo-cutaneous nerve pierces the fascia in front of the elbow ; it lies beneath the median cephalic vein, and divides into branches for the forearm. Internal cutaneous Nerves. The larger internal cutaneous nerve perforates the fascia in two parts, or as one trunk that divides almost INTERNAL CUTANEOUS NERVES. 251 directly into two : — Its external branch passes beneath the median basilic vein to the front of the forearm ; and the internal winds over tlie inner condyle of the humerus to the back of the forearm. A cutaneous offset of the nerve pierces the fascia near the axilla, and reaches as far, or nearly as far as the elbow : it supplies tlie integuments over the inner part of the biceps muscle. The small internal cutaneous nerve (Wrisberg) appears below the pre- ceding, and extends to the interval between the olecranon and the inner condyle of the humerus, where it ends in filaments over the back of the olecranon. The nerve give offsets to the lower tliird of the arm on the inner and posterior surfaces, and joins above the elbow the inner branch of the larger internal cutaneous nerve. The internal cutaneous branch of the musculo-spiral nerve becoming subcutaneous in the upper tliird, winds to the back of the arm, and reaches nearly as far as the olecranon. The intercosto-humeral branch of the second intercostal nerve (p. 226), perforates the fascia near the axilla, and ramifies in the inner side and posterior surface of the arm in the upper half. But the size and distribu- tion of the nerve will depend upon the development of the small internal cutaneous and the offsets of the musculo-spiral. Tlie aponeurosis of the arm is a white shining membrane which sur- rounds the limb, and sends inwards processes between the muscle. Over the biceps muscle it is thinner than elsewhere. At certain points it re- ceives accessory fibres from the subjacent tendons : — thus in front of the elbow an offset from the tendon of the biceps joins it ; and near the axilla the tendons of the pectoralis major, latissimus dorsi, and teres, send pro- longations to it. At the upper part of the limb the fascia is continuous with that of the axilla, and is prolonged over tlie deltoid and pectoral muscles to the scapula and the clavicle. Inferiorly it is continued to the forearm, and is con- nected to the prominences of bone around the elbow joint, especially to the condyloid ridges of the humerus so as to give rise to the intermuscular septa of the arm. Directions. As the back of the arm will not be dissected now, the skin may be replaced on it until the front has been examined. And to keep in place the vessels and nerves at the upper part of the limb, these should be tied together with string in their natural position to one another, and fastened to the coracoid process. Position. The limb is still to lie on the back, but the scapula is to be raised by means of a small block ; and the bladebone is to be fixed in such a position as to render tense the muscles. The inner surface of the arm is to be placed towards the dissector. Dissection. The aponeurosis is to be reflected from the front of the arm by an incision along the centre, like that through the integuments; and it is to be removed on the outer side as far as the outer condyloid ridge of the humerus, but on the inner side rather farther back than the corresponding line, so as to lay bare {)art of the triceps muscle. In rais- ing the fascia the knife must be carried in the direction of the fibres of the biceps muscle ; and to prevent the displacement of the brachial artery and its nerves, fasten them here and there with stitches. In front of the elbow is a hollow containing the brachial vessels: the artery should be followed into it, to show its ending in the radial and ulnar trunks. 252 DISSECTION OF THE ARM. Muscles on the Front of the Arm. There are only three muscles on the fore part of the arm. The one along tlie centre of the Fimb is the biceps ; and that along its inner side, reaching about half way down, is the coraco-brachialis. The brachialis anticus lies beneath the biceps. Some muscles of the forearm are connected to the inner and outer condyles of the humerus, and to the line above the outer condyle. The biceps muscle (fig. 78, ^) forms the ])rominence observable on the front of the arm. It is wider at the middle than at either end; and the upper part consists of two tendinous pieces of different lengths, which are attached to the scapula. Tiie short head arises from the apex of the coracoid process in common with the coraco-brachialis muscle (fig. 73) ; and the long head is attached to the upper part of the glenoid cavity of the scapula, within the capsule of the shoulder joint (fig. 89). Muscular fibres spring from each tendinous head, and blend about the middle of the arm in a fleshy belly, which is somewhat flattened from before back. In- feriorly the biceps ends in a tendon, and is inserted into the tubercle of the radius. The muscle is superficial except at the extremities. At the upper part it is concealed by the pectoralis major and deltoid muscles; and at the lower end the tendon dips into the hollow in front of the elbow, having previously given an offset to the fascia of the arm. Beneath the biceps are the brachialis anticus muscle, the musculo-cutaneous nerve, and the upper part of the humerus. Its inner border is the guide to the brachial artery below the middle of the humerus, but above that spot the coraco- brachialis muscle intervenes between them. The connection of the long head of the biceps with the shoulder joint, and the insertion of the muscle into the radius, will be afterwards learnt. Action. It bends the elbow-joint, and acts powerfully in supinating the radius. When the body is hanging by the hands it will apply the scapula firmly to the humerus, and will assist in raising the trunk. With the arm hanging and the radius fixed, the long head will assist the abductors in removing the limb from the thorax ; and after the limb is abducted, the short head will aid in restoring it to the pendent position. The CORACO-BRACHIALIS (fig. 73, ") is roundish in form, and is named from its attaehments. Its origin is fleshy from the tip of the coracoid process, and from the tendinous short head of the biceps. Its fibres be- come tendinous, and are inserted, below the level of the deltoid muscle, into the ridge on the inner side of the humerus: from tlie insertion an aponeurotic slip is continued upw^ards to the head of the humerus, and is joined by fleshy fibres. Part of the muscle is beneath the pectoralis major (fig. 78), and forms a prominence in the axilla; but the rest is superficial, except at the inser- tion where it is covered by the brachial vessels and the median nerve. The coraco-brachialis conceals the subscapular muscle, the anterior cir- cumflex artery, and the tendons of the latissimus and teres. Along the inner border are the large artery and nerves of the limb. Perforating it is the musculo-cutaneous nerve. Action. Tlie hanging limb is adducted to the thorax by this muscle; and the action is greater in proportion as the humerus is removed from the trunk. The humerus being fixed, the muscle will bring down the scapula, and assist in keeping the articular surfaces of the shoulder joint in apposition. BRACHIAL ARTERY. 253 The BRACHIAL ARTERY (fig. 77, *) is a continuation of the axillary- trunk, and supplies vessels to the upper limb. It begins at the lower border of the teres major muscle, and terminates rather below the bend of the elbow, or "opposite the neck of the radius" (Quain), in two branches — radial and ulnar, for the forearm. In the upper part of its course, the vessel is internal to the humerus, but afterw^ards in front of that bone; and its situation is indicated by the surface depression along the inner border of the biceps and coraco-brachi- alis muscles. Fig. 77. 1. Axillaryartery and branches: the small branch above the figure is the highest thoracic, and the larger branch close below, the acromial thoracic. 2. Long thoracic branch. 3. Subscapular branch. 4. Brachial artery and branches. 5. Superior profunda branch. 6. Inferior profunda branch. 7. Anastomotic branch. 8. Biceps muscle. 9. Triceps muscle. The median and ulnar nerves are shown in the arm ; the median is close to the bra- chial artery. Axillary and Brachial Arteries and their Branches. (Qualirs ".Arteries.") In all its extent the brachial artery is superficial, being covered by tlie integuments and the deep fascia; but at the bend of the elbow it becomes deeper, and is crossed by the prolongation from the tendon of the bice|)S. Posteriorly the artery has the following muscular connections (fig. 78) : — 254 DISSECTION OF THE ARxM. Whilst it is inside the humerus it is placed over the long head of the tri- ceps F, for two inches, but separated partly by the musculo-spiral nerve and profunda vessels; and over the inner head, G, of the same muscle for about an inch and a half. But when the vessel turns to the front of the bone, it lies on the insertion of the coraco-brachialis, c, and on the brachi- alis anticus, h. To the outer side are laid the coraco-brachialis and biceps muscles, c, and b, the latter overlapping it. Veins. Veniie comites lie on the sides of the artery (fig. 78, d), encir- cling it with branches, and the median basilic vein crosses over it at the elbow. The basilic vein is near, and inside the artery above, but is superficial to the fascia in the lower half of the arm. The nerves in relation with the artery are the following:— Tiie internal cutaneous {^) is in contact with the vessel until it perforates the fascia about the middle of the arm. The ulnar nerve; (*) lies to the inner side as far as the insertion of the coraco-brachialis muscle; and the musculo- spiral (fig. 69, *) is behind for a distance of two inches. The median nerve (*) is close to the vessel throughout, but alters its position in this way: — as low as the insertion of the coraco-brachialis it is placed on the outer side, but it then crosses obliquely either over or under the artery, and becomes internal about two inches above the elbow joint. Peculiarities in position. The brachial trunk may leave the inner border of the biceps in the lower half of the arm, and course along tlie intermuscular septum, with or without the median nerve, to the inner condyle of the humerus. At this spot the vessel is directed to its ordinary position in front of the elbow, either through or beneath the fibres of the pronator teres, which has then a wide origin. In this unusual course the artery lies behind a projecting bony point of the hu- merus. Muscular covering. In some bodies the humeral artery is covered by an addi- tional slip of origin of the biceps, or of the brachialis anticus muscle. And some- times a slip of the brachialis may conceal, in cases of high origin of the radial, the remainder of the arterial trunk continuing to the forearm. Branches spring both externally and internally from the brachial artery (fig. 77). Those on the outer side, musciilar., supply tbe coraco-braciii- alis, biceps, and brachialis anticus; those on the inner side are named superior and inferior profunda, nutritious, and anastomotic. The superior profunda branch (*) is larger than the others, and leaves the artery near the lower border of the teres major; it winds backwards with the musculo-spiral nerve to the triceps muscle, and will be dissected with the back of tlie arm. The inferior profunda branch (*) arises opposite the coraco-brachialis muscle, and accompanies the ulnar nerve to the interval between the olecranon and the inner condyle of the humerus. There it anastomoses with the posterior ulnar recurrent and anastomotic branches, and sup- ])lies the triceps. It arises often in common with the superior profunda artery. A nutritious artery of the bone shaft begins near the preceding branch, and enters the large aperture about the middle of the humerus; it is dis- tributed to the osseous and the medullary substance. The anastomotic branch (') arises one to two inches above the elbow, and courses inwards througii the intermuscular septum to the hollow be- tween the olecranon and the inner condyle of the humerus. Here the artery inosculates with the inferior profunda and [)OSterior ulnar recurrent branches, and gives twigs to the triceps muscle: one of the offsets forms NERVES OF THE ARM, 255 an arch across the back of the humerus with a branch of the superior pro- funda. In front of the elbow joint the anastomotic branch sends an offset to the pronator teres muscle: this joins tiie anterior ulnar recurrent branch. Vasa aherrantia. Occasionally long slender vessels connect the bra- chial or the axillary trunk with the radial artery ; the accessory vessel very rarely ends in the ulnar artery. The BRACHIAL VEINS (tig. 78, d) accompany the artery, one on each side, and have branches of communication across that vessel; they receive contributing veins corresponding with the branches of the arteries. Su- periorly they unite into one, which joins the axillary vein near the sub- scapular muscle. Nerves of the Arm (fig. 78). The nerves on the front of the arm are derived from the terminal cords of the brachial plexus. Few of them furnish offsets above the elbow, but they are continued, for the most part without branching, to the forearm and the hand. The cutaneous branches of some of them have been referred to (p. 250). MnscLEs AND Deep Vessels and Nervi s of the Arm, (Illustrations of Dissections.) Muscles : Nerves : A. Pectoralis major. 1. Median. B. Biceps. 2. Internal cutaneous, c. Coraco-brachialis. 3. Nerve of Wrisbeiy. D and K. Latissimus and teres. 4. Ulnar. F. Long head of the triceps. 5. Muscular to the triceps. «. Inner head of triceps. * 6. Internal cutanexiis from ihe H. Brachialis anticus. niusculo-spiral. The median nerve (' ) arises from the brachial plexus by two roots, one from the outer, and the other from the inner cord (p. 236). Its destina- tion is to tlie palm of the hand; and it accompanies tlie brachial artery to the forearm. Beginning on the outer side of the artery, the nerve crosses over or under it about the middle of the arm, and is placed on tlie inner side a little above the elbow. It does not give any branch in tlie arm; but there may be a fasciculus connecting it with the musculo-cuta- neous nerve. Its connections with muscles are the same as those of the artery. The ulnar 7urve (*), derived from the inner cord of the brachial plexus, 256 DISSECTION OF THE ARM. ends fit the inner side of the hand. In the arm the nerve lies at first close to the inner side of the axillary, and the brachial artery, as far as tlie insertion of the coraco-brachialis ; then leaving the bloodvessel, it is di- rected inwards through the inner intermuscular septum to the interval be- tween the olecranon and the inner condyle, being surrounded by the mus- cular fibres of the triceps. There is not any branch from the nerve till it reaches the elbow-joint. The internal cutaneous (^) is a tegumentary nerve of the forearm, to which it is prolonged like the others. Arising from the inner cord of the plexus, it is at first superficial to the humeral artery as far as the middle of the arm, where it divides into two branches that perforate the investing fascia and reach the forearm (p. 250). Near the axilla it furnishes a small cutaneous offset to the integuments of the arm. The small internal cutaneous nerve (^) (nerve of Wrisberg) arises with the preceding. Concealed at first by the axillary vein, it is directed in- wards beneath (but sometimes through) that vein, and joins with the inter- costo-humeral nerve. Afterwards it lies along the inner part of the arm as far as the middle, where it perforates the fascia to end in the integu- ment (p. 251). • The musculo-cutaneous nerve (nerv. perforans, Casserii), named from supplying muscles and integuments, ends on the surface of the forearm. It leaves the outer cord of the brachial plexus opposite the lower border of the pectoralis minor (fig. 70) and perforates directly the coraco-brach- ialis : it is then directed obliquely to the outer side of the limb between the bicejjs and brachialis anticus muscles. Near the elbow it becomes a cutaneous nerve of the forearm. Branches. The nerve furnishes branches to the muscles in front of the humerus, viz., to the coraco-brachialis as it passes through the fibres, and to the biceps and brachialis anticus where it is placed between them. Dissection. The brachialis anticus muscle will be brought into view by cutting through the tendon of the biceps near the elbow, and turning upwards this muscle. The fascia and areolar tissue should be taken from the fleshy fibres ; and the lateral extent of the muscle should be well de- fined on each side, so as to show that it reaches the intermuscular septum largely on the inner side, but only for a short distance above on the outer side. Some care is required in detaching the brachialis externally from the muscles of the forearm, to which it is closely applied. As the muscles are separated the musculo-spiral nerve with a small artery comes into sight. The BRACHIALIS ANTICUS (fig. 78, ^) covers the elbow-joint, and the lower half of the front of the humerus. It drises from the anterior sur- face of the humerus below the insertion of the deltoid muscle ; and from the intermuscular septa on the sides, viz., from all the inner, but from only the u[)per part of the outer (about one inch and a half.) The fleshy fibres converge to a tendon, which is inserted into the impression on the front of the coronoid process of the ulna (p. 271). This muscle is concealed by the biceps. On it lies the brachial artery, with the median, musculo-cutaneous, and musculo-spiral nerves. It covers tlie humerus and the articulation of the elbow. Its origin embraces by two parts the attachment of the deltoid ; and its insertion is placed between two fleshy pieces of the flexor profundus digitorum. The inner border reaches the intermuscular septum in all its length ; but the outer is sepa- rated from the external intermuscular septum below by two muscles of TRICEPS EXTENSOR OF MUSCLE 25' the forearm (supinator longus and extensor carpi radialis longior), which extend upwards on the humerus. Action. The brachialis brings forwards the ulna towards tlie humerus, and bends the elbow-joint. If the ulna is fixed, as in climbing with the hands above the head, the muscle bends the elbow-joint by raising the humerus. BACK OF THE ARM. Position. During the examination of the back of the arm, the limb is to be raised in a semiflexed position by means of a block beneath the elbow. The scapula is to be brought nearly in a line with the humerus, so as to tighten the muscular fibres ; and it is to be fastened with hooks in that position. Fig. 79. Muscles : A. Long head of the triceps. B. Outer head, with a bit of whalebone beneath it to mark the extent of its attachment down the humerus, c. Inner head of the triceps. D. Anconeus- K. Supinator longns. F. Extensor carpi radialis longus. G. Teres major. H. Teres minor. I. Infra-spinatus, cut across. J. Supra-spinatus, cut through. Arteries : a. Supra-scapular. 6. Dorsal scapular. c. Posterior circumflex. Nerves : 1. Supra-scapular. 2. Posterior circumflex. Dissection of thk Dorsal Scapitlar Ykssels and Xerve, and of the Triceps Mcsclb • OF THE Arm. Dissection (fig. 79). On the back of the arm there is one muscle, the triceps, with the musculo-spiral nerve and superior profunda vessels. The skin having been reflected already, the muscle will be laid bare readily, for it is covered only by fascia. To take away the fascia, carry an inci- sion along the middle of the limb to a little below the elbow ; and in reflect- ing it, the subaponeurotic loose tissue should be removed at the same time. 17 258 DISSECTION OF THE ARM. Separate the middle from the inner and outer heads of the muscle, and trace the musculo-spiral nerve and vessels beneath it. Define the outer head which reaches down to the spot at which the musculo-spiral nerve ap})ears on the outer side. The TRICEPS MUSCLE (fig. 79), is divided superiorly into three parts or heads of origin, inner, outer, and middle : two of these are attached to the humerus, and one to the scapula. The middle piece, or head, a, is the longest, and has a tendinous origin, about an inch wide, from the inferior costa of the scapula close to the glenoid cavity, where it is united with the capsule of the shoulder joint. The outer head, b, is narrow and arises from the back of the humerus above the spiral groove, extending from the root of the large tuberosity to that groove. The inner head, c, fleshy and wide, arises from the posterior surface of the humerus below the spiral groove, reaching laterally to the intermuscular septa, and gradually tapering upwards as far as the insertion of the teres major (Theile). From the different heads the fibres are directed with varying degrees of inclination to a common tendon at the lower part. Inferiorly the muscle is inserted into the end of the ole- cranon process of the ulna, and gives an expansion to the ai)oneurosis of the forearm. Between the tip of the olecranon and the tendon is a small bursa. The triceps is superficial, except at the upper part where it is overlapped by the deltoid muscle. It lies on the humerus, and conceals the musculo- spiral nerve, the superior profunda vessels, and the articulation of the elbow. On the sides the muscle is united to the intermuscular septa ; and the lower fibres are continuous externally with the anconeus — a muscle of the forearm. Action. All the parts of the triceps combining in their action will bring the ulna into a line with the humerus, and extend the elbow-joint. As the long head passes the shoulder it can depress the raised humerus, and adduct the bone to the thorax. The intermuscular septa are fibrous processes continuous with the in- vesting aponeurosis of the arm, which are fixed to the ridges leading to the condyles of the humerus : they intervene between the muscles on the front and back of the limb, and give attachment to fleshy fibres. The internal is the strongest, and reaches as high as the coraco-brachialis muscle, from which it receives some tendinous fibres. Tiie brachialis an- ticus is attached to it in front, and the triceps behind ; and the ulnar nerve, and the inferior profunda and anastomotic vessels pierce it. The external septum is thinner, and ceases at the deltoid muscle. Be- liind it is the triceps ; and in front are the brachialis anticus, and the muscles of the forearm (supinator longus and extensor carpi radialis longus) arising above the condyle of the humerus : it is i)ierced by the musculo-spiral nerve and the accompanying vessels. Dissection. To follow the superior profunda vessels and the musculo- spiral nerve, the middle head of the triceps should be cut across over them, and the fatty tissue should be removed. The trunks of the artery and nerve are to be afterwards followed below the outer head of the trice[)S to the front of the humerus. To trace out tiie branches of the nerve and artery, which descend to the olecranon and the anconeus muscle, the tricei)S is to be divided along the line of union of the outer with the middle head. The superior profunda branch of the brachial artery (p. 254) turns to MUSCULO-SPIRAL NERVE. 259 the back of the humerus between the inner and outer heads of the triceps; in tliis position it supplies branches to tlie triceps and deltoid muscles, and is continued onwards in the groove in the bone to the outer part of the arm, where it divides into its terminal offsets : — One of these, which is very small, courses on the musculo-spiral nerve to the front of the elbow, anastomosing with the recurrent radial branch : Avhilst others continue along the intermuscular septum to the elbow, and join the radial and pos- terior interosseous recurrent branches. Branches. Most of the muscular offsets of the vessels descend to the olecranon, supplying the triceps, and communicate with the inferior pro- funda and anastomotic branches of the brachial artery (p. 254) ; and with the recurrent branches of the arteries of the forearm except the anterior ulnar. One slender offset accompanies a branch of the musculo-spiral nerve, and ends in the anconeus muscle below the outer condyle of the humerus. Two or more cutaneous offsets arisi; on the outside of the arm, and accompany the superficial nerves. The musculo-spiral nerve (fig. 70) is the largest trunk of the posterior cord of the brachial plexus (p. 236) and is continued along the back and outer part of the limb to the hand. In the arm the nerve winds with the profunda artery beneatli the triceps muscle. At the outer aspect of the arm it is continued between the brachialis anticus and supinator longus muscles to the external condyle of the humerus, in front of which it divides into the radial and posterior interosseous nerves. The nerve gives muscu- lar branches, and the following cutaneous offsets to the inner and outer parts of the limb. a. The internal cutaneous branch of the arm (fig. 78, ^) is of small size, and arises in the axillary space in common with the branch to the inner head of the triceps ; it is directed across the posterior boundary of the axilla to the inner side of the arm, where it becomes cutaneous in the upper third, and is distributed as before said (p. 250). b. The external cutaneous branches springing at the outer side of the limb are two in number : they are distributed in the integuments of the arm and forearm (p. 250). c. The muscular branches to the triceps are numerous, and supply all three heads. One slender offset for the inner head, arises in common with the inner cutaneous branch, and lies close to the ulnar nerve till it enters the muscular fibres at the lower third of the arm. Another long and slender branch behind tiie humerus, appearing as if it ended in the triceps, can be followed downwards to the anconeus muscle. d. On the outer side of the limb the musculo-spiral nerve supplies the brachialis anticus in part, and two muscles of the forearm, viz., supinator longus and extensor carpi radialis longior. ISubanconeus muscle. A thin flesliy stratum of the under part of the triceps near the elbow has been so named. It is described as consisting of two fasciculi, inner and outer, which are attached above the fossa for the olecranon, and end in the synovial sac of the joint. A corresponding muscle is placed beneath the extensor of the knee joint. Action. It is said to raise the synovial membrane in extension of the joint. Directions. As the dissection of the arm has been completed as far as the elbow, it will be advisable to keep moist the shoulder joint until it is examined with the other ligaments. 260 DISSECTION OF THE FRONT OF THE FOREARM. Section IV. THE FRONT OF THE FOREARM. Position. The limb is to be placed with the palm of the hand upper- most ; and the marking of the surface, and the projections of the bone, are first to be noted. Surface-marking. On the anterior aspect of the forearm are two lateral depressions, corresponding with the position of the main vessels. The external is placed over the radial artery, and inclines towards the middle of , the limb as it approaches the elbow. The internal groove is evident only beyond the middle of the forearm, and points out the place of the ulnar artery. The bones (radius and ulnar) are sufficiently near the surface to be traced in their whole length : each ends below in a point — the styloid process ; and that of the radius is the lowest. A transverse line separates the forearm from the hand, and the articulation of the wrist is about an inch above it. On each side of the palm of the hand is a lateral projection ; the exter- nal of these (thenar) is formed by muscles of the thumb, and the internal (hypo-thenar) by muscles of the little finger. Between the projections is the hollow of the palm, which is pointed towards the wrist. Two trans- verse lines are seen in the palm, but neither reaches completely across it : the anterior one will direct to the line of the articulations between the metacarpus and the phalanges, but is about a quarter of an inch behind the three inner joints when the fingers are extended. The superficial palmar arch of arteries reaches forwards a little way into the hollow of the hand, and its position may be marked by a line across the palm from the root of the thumb, when that digit is placed at a right angle to the hand. Transverse lines are seen on both aspects of the joints of the thumb and fingers. The lines on the palmar surface of the fingers may be used to detect the articulations of the phalanges. Thus the joint between the metacarpal phalanx and the next will be found about a line in front of the chief transverse groove ; whilst the articulation between the last two pha- langes is situate about a line in front of the single mark. Dissection. With the limb lying flat on the table, an incision is to be carried through the skin along the middle of the front of the forearm, as far as an inch beyond the wrist ; and at its termination a transverse one is to cross it. The skin is to be reflected carefully from the front and back of the forearm, without injury to tlie numerous superficial vessels and nerves beneath ; and it should be taken also from the back of the hand, by prolonging the ends of the transverse cut along each margin to a little beyond the knuckles. The whole of the forefinger should have the integ- ument removed from it, in order that the nerves may be followed to the end. The superficial vessels and nerves can be now traced in the fat ; they have the following position, and most of them liave been partly dissected : Along the inner side, in front of the forearm witli the ulnar veins, is the continuation of the internal cutaneous uerve ; and near the wrist there is CUTANEOUS VEINS OF FOREARM. 261 occasionally a small offset from the ulnar nerve. On the outer side with the radial vein is the superficial part of the musculo-cutaneous nerve. Close to the hand, in the centre of the forearm, and inside the tendon of the flexor car[)i radialis which can be rendered prominent by extending the wrist, the small palmar branch of the median nerve should be sought beneath the fat. On the ulnar artery, close inside the pisiform bone, a small palmar branch of the ulnar nerve is to be looked for. At the back of the forearm the largest external cutaneous branch of the musculo-spiral nerve is to be traced onwards ; and offsets are to be followed to this surface from the nerves in front. On the posterior part of the hand is an arch of superficial veins. Wind- ing back below the ulna is the dorsal branch of the ulnar nerve ; and lying along the outer border of tlie liand is the radial nerve : these should be traced to the fingers. Cutaneous Veins. The superficial veins are named median, radial, and ulnar, from their position in the limb. Superficial arch on the hack of the hand. This arch is more or less per- fect, and receives the posterior superficial digital veins. At the sides the arcli terminates in the radial and ulnar veins. The radial vein begins in the outer part of the arch above mentioned, and in some small radicles a,t the back of the thumb. It is continued along the forearm, at first behind and then on tlie outer border as far as the elbow, where it gives rise to the cephalic vein by its union with the outer branch of the median vein (fig. 76, ''). The ulnar veins are anterior and posterior, and occupy the front and back of the limb : — The anterior arises near the M^rist by the junction of small roots from the hand, and runs on the inner part of the forearm to the elbow ; here it unites with the inner branch of the median, and forms the basilic vein (fig. 76,^). The posterior ulnar vein is situate on the back of the limb. It com- mences by the union of a branch, '* vena salvatella," from the back of the little finger, with an offset of the venous arch ; it is continued along the back of the forearm nearly to the elbow, and bends forwards to open into the anterior ulnar vein. The median vein takes origin near the wrist by small branches which are derived from the palmar surface of the hand ; and it is directed along the centre of the forearm nearly to the elbow. Here the vein divides into external and internal branches (median basilic and median cephalic), which unite, as before seen (fig. 76, *), with radial and ulnar veins. At its point of bifurcation the median receives a communicating branch from a vein (vena comes) beneath the fascia. Cutaneous Nerves. Some of the superficial nerves of the forearm are continued from the arm : — those on the inner side from the large in- ternal cutaneous nerve ; and those on the outer, from the two external cutaneous nerves of the musculo-spiral, and the musculo-cutaneous. On the forepart of the limb there is occasionally a small offset of the ulnar nerve near the wrist. On the back of the hand is the termination of the radial nerve, together with a branch of the ulnar nerve. The internal cutaneous nerve (p. 2r)6) is divided into two parts. The anterior branch extends on the front of the forearm as far as the wrist, and supplies the integuments on the inner half of the anterior surface. Near the wrist it communicates sometimes with a cutaneous offset from 262 DISSECTION OF THE FRONT OF THE FOREARM. the ulnar nerve. The posterior branch continues along the back of the forearm (ulnar side) to rather below the middle. The cutaneous part of the musculo-cutaneous nerve (p. 250) is pro- longed on the radial border of the limb to the ball of the thumb, over which it terminates in cutaneous offsets. Near the wrist the nerve is placed over the radial arter}', and some twigs pierce the fascia to ramify on the vessel and supply the carpus. A little above the middle of the forearm the nerve sends backwards a branch to the posterior aspect, which reaches nearly to the wrist, and communicates with the radial, and the following cutaneous nerve. The external cittaneous branch of the musculo-spiral nerve (p. 259) after passing the elbow, turns to the hinder part of the forearm, and reaches as far Us the wrist. Near its termination it joins the pi-eceding cutaneous nerve. The radial nerve ramifies in the integument of the back of the hand and some of the digits. It becomes cutaneous at the outer border of the forearm in the lower third, and after giving some filaments to the poste- rior aspect of the limb, divides into two branches: — One (external) is joined by the musculo-cutaneous nerve, and is dis- tributed on the radial border and the ball of the thumb. The other branch (internal) supplies the remaining side of the thumb, both sides of the next two digits, and half the ring finger ; so that the radial nerve distributes tlie same number of digital branches to the dorsum as the median nerve furnishes to the palmar surface. This portion of the radial nerve communicates with the musculo-cutaneous and ulnar nerves ; and the offsets to the contiguous sides of the ring and middle fingers is joined by a twig from the dorsal branch of the ulnar nerve. On the side of the fingei-s each of these dorsal digital branches is united with an offset from the digital nerve on the palmar surface. The dorsal branch of the ulnar nerve gives offsets to the rest of the fingers and the back of the hand. Appearing by the styloid process of the ulnar, it joins the radial nerve in an arch across the back of the hand, and is distributed to both sides of the little finger, and to the ulnar side of the ring finger : it communicates with the part of the radial nerve supplying the space between the ring and middle fingers. The ulnar nerve furnishes branches to the same digits on the palmar surface. The aponeurosis of the forearm is continuous with a similar investment of the arm. It is of a pearly Avhite color, and is formed of fibres which cross obliquely : it furnishes sheaths to the muscles, and is thicker behind tlian before. Near the elbow it is stronger than towards the hand; and at that part it receives fibres from the tendons of the biceps and brachialis anticus, and gives origin to the muscles attached to the inner condyle of the humerus. On the back of the limb the aponeurosis is connected to the margins of the ulna, so as to leave tlie upper part of the bone subcutaneous ; and it is joined by fibres from the tendon of the triceps. Horizontal processes are sent downwards from tlie aponeurosis to sepa- rate the superficial and deep layers of muscles, both on the front and back of the forearm ; and longitudinal white bands indicate the position of the intermuscular [)rocesses which isolate one muscle from another, and give origin to the muscular fibres. At the wrist? tlie fascia joins the anterior annular ligament ; and near that band the tendon of the palmaris longus pierces it, and receives a sheath APONEUROSIS OF FOREARM. 263 from it. Close to the pisiform bone there is an aperture through wliich the ulnar vessels and nerve enter the fat of the hand. Behind the wrist it is thickened by transverse fibres, giving rise to the posterior annular ligament ; but on the back of the hand and fingers the fascia becomes very thin. Dissection. The skin is to be replaced on the back of the forearm and hand, in order that the denuded parts may not become dry. Beginning the dissection on the anterior surface of the limb, let the student divide the aponeurosis as far as the wrist, and take it away with the cutaneous vessels and nerves, except the small palmar cutaneous offsets of the median and ulnar nerves near the wrist. In cleaning the muscles it will be impossible to remove the aponeurosis from them at the upper part of the forearm without detaching muscular fibres. In front of the elbow is the hollow, already partly dissected, between the two masses of muscles arising from the inner and outer sides of the humerus. The space should be carefully cleaned, so as to display the brachial and forearm vessels, the median nerve and branches, the musculo- spiral nerve, and the recurrent radial and ulnar arteries. In th.e lower half of the ibrearm a large artery, radial, is to be laid bare along tiie radial border ; and at the ulnar side, close to the annular liga- ment, the trunk of the ulnar artery will be recognized, as it becomes superficial. These vessels and their branches should be carefully cleaned ; but the collateral muscles should be fixed with stitches to prevent their displacement. The anterior 'annular ligament of the wrist, which arches over the ten- dons passing to the hand, is next to be defined. This strong band is at some depth from the surface ; and whilst the student removes the fibrous tissue superficial to it, he must take care of the small branches of the median and ulnar nerves to the palm of the hand. The ulnar vessels and nerve pass over the ligament, and will serve as a guide to its depth. Hollow in front of the elbow (fig. 80). Ihis hollow corresponds with the popliteal space at the knee, and is situate between the inner and the outer muscles of the forearm. The interval is somewhat triangular in shape, and the wider part is towards the humerus. It is bounded on the outer side by the supinator longus muscle, and on the inner side by the pronator teres. The aponeurosis of the limb is stretched over the sj)ace ; and the bones, covered by tlie brachialis anticus and supinator brevis, form the deep boundary. Contents. In the hollow are lodged the termination of the brachial artery with its veins, and the median nerve ; the musculo-spiral nerve ; the tendon of the biceps muscle ; and small recurrent vessels, with much fat and a few glands. These several parts have the following relative position : The tendon of the biceps is directed towards the outer boundary to reach the radius ; on the outer side, concealed by the supinator longus muscle, is the musculo- spiral nerve. Nearly in tlie centre of the space are the brachial artery and veins and the median nerve, the nerve being internal ; but as the artery is inclined to the outer part of the limb, they soon become distant from one another about half an inch. The brachial artery divides here into two trunks — radial and ulnar ; and the recurrent radial and ulnar branches appear in the space, one on the outer and the other on the inner side. Two or three lymphatic glands lie on the sides of the artery, and one below its point of splitting. 264 DISSECTION OF THE FRONT OF THE FOREARM, ■12 Fig. 80. Muscles on the front of the forearm (fig. 80). The muscles on the front of the forearm are divided into a superficial and a deep layer. In the superficial layer there are five muscles, which are fixed to the inner condyle of the hu- merus, mostly by a common tendon, and lie in the undermentioned order from the middle to tlie inner side of the limb : pronator radii teres, fiexor carpi radialis, palmaris longus, flexor carpi ulnaris ; and deeper and larger than any of these is the fiexor sublimis digitorum. The deep layer will be met with in a subsequent dissection (p. 270). The pronator radii teres (fig. 80°, 3) arises from the inner condyle of the humerus by the common tendon ; from the ridge above the condyle by fleshy fibres ; from the inner part of the coro- noid process by a second tendinous slip ; and from the fascia, and the septum between it and the next muscle. It is inserted by a flat tendon into an im- pression, an inch in length, on the middle of the outer surface of the radius. The muscle is superficial except at the insertion, where it is covered by tlie radial artery, and some of the outer set of muscles, viz., supinator longus, and radial extensors of the wrist. The j)ronator forms the inner boundary of the triangular space in front of the elbow ; and its inner border touches the flexor carpi radialis. By gently se[)arating the muscle from the rest, it will be found to lie on the brachialis anticus, the flexor sublimis digitorum, and the ulnar artery and the median nerve : the second small head of origin is directed inwards between that artery and nerve. Action. Tlie pronator assists in bringing for- wards the radius over the ulna, so as to pronate the hand. AVhen the radius is fixed the muscle raises that bone towards the humerus, bending the elbow-joint. The flexor carpi radialis (fig. 80, *) takes its origin from the common tendon, from the aponeurosis of the limb, and from the intermuscular septum on each side. The tendon of tlie muscle, becoming free from fleshy fibres about tlie middle of the forearm, passes through a groove in the os trapezium, outside the anterior annular ligament, to be inserted mainly into the base of the meta- carpal bone of the index finger, and by a slip into that of the middle finger. The muscle rests chiefly on the flexor sublimis digitorum ; but near the wrist it lies over the flexor longus pollicis — a muscle of the deep layer. As low as the middle of the forearm the muscle corresponds externally with the pronator teres, and H ri. 10 SCPBRFICIAL VIEW OF THE FOREARM (Quain's Arte- ries). 1. Radial artery with its nerve outside. 2. Uluar artery and nerve where they are suiier- ficial. 3. Pronator teres. 4. Flexor carpi radialis. 5. Paluians longus. 6. Flexor sublimis, 7. Flexor carpi ulnaris. 8. Supinator longus. 9. Biceps. RADIAL ARTERY AND BRANCHES. 265 below that with the radial artery to which its tendon is taken as the guide. The ulnar border is in contact at first with tlie palmaris longus muscle, and for about two inches above the wrist, with the median nerve.^ Action. The hand being free the muscle flexes first the wrist joint, inclining the hand somewhat to the radial side ; and will assist in bringing forwards the lower end of the radius in pronation. Still continuing to contract, it bends the elbow. Tlie PALMARIS LONGUS (fig. 80, ^) is often absent : or it may present great irregularity in the proportion between the fleshy and tendinous parts. Its origin is connected, like tiiat of the preceding muscle, to the common tendon, the fascia, and the intermuscular septa. Its long thin tendon is continued along the centre of the forearm ; and piercing the aponeurosis, it passes over the annular ligament to end in the palmar fascia, and to join by a tendinous slip the short muscles of the thumb. The palmaris is situate between the flexor carpi radialis and ulnaris, and rests on the flexor sublimis digitorum. Action. Rendering tense the palmar fascia, the palmaris will afterwards bend the wrist and elbow, like the other muscles of the superficial layer. The FLEXOR CARPI ULNARIS (fig 80, ') has an aponeurotic origin from the inner condyle of the humerus ; from the inner side of the olecranon ; and from the ridge of the ulna between the internal and posterior surfaces for three-fourths of the length. Most of the fibres are continued vertically downwards, but others obliquely forwards to a tendon on the anterior part of the muscle in the lower half, some joining it as low as the wrist ; and the tendon is inserted into the pisiform bone, an offset being sent to the muscles of the little finger. One surface of the muscle is in contact with the fascia ; and its tendon, which can be felt readily through the skin, may be taken as the guide to the ulnar artery. To its radial side are the palmaris and flexor digitorum sublimis muscles. When the attachment to the inner condyle has been divided, the muscle will be seen to conceal the flexor digitorum sublimis and flexor profundus, the ulnar nerve, and the ulnar vessels ; between the attachments to the condyle and the olecranon the ulnar nerve enters the forearm. Action. The wrist is bent and the hand is drawn inwards by the con- traction of the muscle. The RADIAL ARTERY (fig. 80, ^) is onc of the vessels derived from the bifurcation of the brachial trunk ; and its destination is the [)alm of the hand. It is placed first along the outer side of the forearm as far as the end of the radius ; next it winds backwards below the extremity of that bone : and it enters finally the palm of the hand through the first inter- osseous space. In consequence of this circuitous course the artery will be found in three diflerent dissections, viz., the front of the forearm, the back of the wrist, and the palm of the hand. In the front of the forearm. In this part of the limb the position of the artery will be marked, on the surface, by a line from the centre of the hollow of the elbow to the fore part of the styloid process of the radius. At first it lies on the inner side of the radius, but afterwards over that bone. This vessel is smaller than the ulnar artery, though it appears in direction to be the continuation of the brachial trunk ; and it is partly ' In the body of a woman which was well developed, the muscle was absent on both sides. 266 DISSECTION OF THE FRONT OF THE FOREARM. deep and }'artly superficial, but where it is more superficial in the lower half it cai) be felt beating as the pulse near the wrist during life. In its upper half the vessel is placed beneath the supinator longus (^) ; and rests successively on the following muscles, the fleshy supinator brevis, the pronator teres (^), part of the thin origin of the flexor sublimis (^), and sometimes on the biceps tendon ('). Veins. Venae comites lie on the sides, with cross branches over the artery. Nerve. The radial nerve is parallel to, and outside it, but separated by a slight interval. In its lower half the artery with its vena3 comites is superficial, being covered only by the teguments and the deep fascia. Here it is placed in a hollow between the tendons of the supinator longus (^) and flexor carpi radicalis (*). It lies from above down on the origin of the flexor sublimis, on two other muscles of the deep layer, viz., flexor poUicis longus and pronator quadratus, and lastly on the end of the radius. Nerves. The radial nerve is still on the outer side until it passes back- wards beneath the tendon of the supinator longus, and becomes cutaneous. Superficial to the lower end are the ramifications of the muscnlo-cutaneous nerve, some of which reach the vessels (p. 2G2). Branches. The radial artery furnishes many unnamed muscular and nutrient offsets to the surrounding parts ; and three named branches, viz., recurrent radial, superficial volar, and anterior carpal. a. The radical recurrent is the first brancli, and supplies the muscles of the outer side of the limb. Its course is almost transverse to the supi- nator longus, beneath which it terminates in that muscle and the two radial extensors of the wrist. One offset ascends beneath the supinator, and anastomoses with the superior profunda branch of the brachial artery. b. The superjicial volar branch (fig. 83, c) arises usually near the lower end of the radius. It is directed towards the palm of the hand, across or through the mass of muscles in the ball of the tliumb, and it either ends in those muscles, or joins the superficial palmar arch. c. The anterior carpal branch is very inconsiderable in size, and will be seen in the examination of the deep layer of muscles. Arising rather above the end of the radius, it passes transversely at the lower border of the pronator quadratus, and anastomoses with a similar branch from the ulnar artery : from the arch thus formed, offsets are given to the corpus. Peculiarities of the radial artery. When the radial arises high in the arm, its course is close to the brachial artery, along the edge of tlie biceps muscle ; and in passing the bend of the elbow it may be occasionally subcutaneous, viz., above the deep fascia, and be liable to injury in venesection. In the forearm it may be likewise subcutaneous and superficial to the supinator longus muscle. Dissection. To bring into view the flexor sublimis digitorum, tlie flexor carpi radialis and palmaris longus must be cut through near the inner con- dyle of the humerus, and turned to one side. Small branches of the ulnar artery and median nerve may be seen entering the under surfaces of those muscles. For the present, tlie pronator teres may be left uncut. The FLEXOR DIGITOKUM SUliLIMIS vcl PP^KFOKATUS (fig. 80,^) is the largest of the muscles of the superficial layer, and is named from its posi- tion to {mother flexor in the deep layer. It arises from the inner condyle of the humerus and the internal lateral ligament, and from the intermus- cular septa in common with other muscles ; it takes origin in addition from ULNAR ARTERY AND BRANCHES. 267 the bones of the forejirm, viz., fi'om the inner part of the coronoid process of the ulna ; from the oblique line below the radial tubercle ; and from the anterior margin of the radius as far as, or one or two inches below the insertion of the pronator teres. Rather below the middle of the forearm the muscle ends in four tendons, which are continued beneath the annular ligament and across the hand, to be inserted into the middle })halanges of the fingers, after being perforated by the tendons of the deep flexor. The flexor sublimis is concealed by the other muscles of the superficial layer ; and the radial vessels lie on the attachment to the radius. Along the inner border is the flexor carpi ulnaris, with the ulnar vessels and nerve. The tendons of the muscle are arranged in pairs before they pass beneath the annular ligament of the wrist ; — the middle and ring finger tendons being anterior, and those of the index and little finger posterior in position. On dividing the coronoid and condyloid attachments, the muscle will be seen to cover two flexors of the deep layer (flexor digitorum pro- fundus and flexor poUicis), the median nerve, and the upper part of the ulnar artery. Action. This flexor bends primarily the middle joint of each finger ; and is then able to bring the nearest phalanx towards the palm in consequence of being bound thereto by a sheath. But when the nearest phalanx is fixed by the extensor of the fingers, it remains straight whilst the super- ficial flexor moves the second phalanx. After the fingers are bent the muscle will help in flexing the wrist and elbow joints. The ULNAR ARTERY (fig 81, ^) is the larger of the two branches coming from the bifurcation of the brachial trunk ; and is directed along the inner side of the limb to the palm of the hand, where it forms the superficial palmar arch, and joins offsets of the radial artery. In the forearm the vessel has an arched direction ; and its depth from the surface varies in the first and last parts of its course. In the iij^per half the artery is inclined obliquely inwards from the centre of the elbow to the inner part of the limb, midway between the elbow and wrist. It courses between the superficial and deep layers of muscles, being covered by the pronator teres, flexor carpi radialis, palmaris longus, and flexor sublimis. Beneath it lie the brachialis anticus, for a short distance, and the flexor profundus, c. Veins. Two companion veins are situate on the sides of the artery, and join freely over it. Nerves. The median nerve (^) lies to the inner side of the vessel for about an inch, but then crosses over it to gain the outer side. About the middle of the forearm the ulnar nerve {*) approaches the artery and con- tinues thence on the inner side. In the lower half it has a straight course to the pisiform bone, and is covered by the teguments and fascia, and the flexor carpi ulnaris as far as the wrist. To the outer side are the tendons of the flexor sublimis. Be- neath it is the flexor profundus, c. Veiiis. Two companion veins accompany the artery, as in the upper part, and are united across it at intervals. Nerves. The ulnar nerve (*) lies close to, and on the inner side of the vessels ; and a small branch (^), sending twigs around the artery, courses to the ]mlm of the hand. On the annular ligament of the wrist the artery has passed through the 268 DISSECTION OF THE FRONT OF THE FOREARM. fascia and lies close to the pisiform bone. The ulnar nerve, with its palmar branch, still accompanies the vessel on the inner side. Fig. 81. ifuscles : A. Pronator teres. B. Flexor longiis pollicis. c. Flexor digitoruni per- forans. D. Pronator quadratas. E. Flexor carpi ulnaris. Arteries : a. Radial trunk. b. Cutaneous branch of it to the palm of the hand. G. Ulnar trunk. d. Its recurrent branch. /. Branch with the median nerve. e. Anterior interosseous. g. Brachial trunk. Nerves : 1. Median. 2. Anterior interosseous. 3. Cutaneous palmar branch. 4. Ulnar trunk. 5. Cutaneous palmar branch of ulnar. Dissection op the Deep Later op Mpscles op the Forearm, and op the Vessels and Nerves between the Two Layers op Muscles of the Forearm. (Illustrations of Dissections.) Branches. The greater number of the collateral offsets of the artery are distributed to the muscles. But the named branches are the following : — a. Tlie anterior ulnar recurrent branch (c?) arises generally in common with the next, and ascending on the brachialis anticus muscle inosculates with the small anastomotic artery beneath the pronator radii teres. It gives offsets to the contiguous muscles. ULNAR NERVE. • 269 h. The posterior ulnar recurrent branch (c?), of larger size than the anterior, is inclined beneath the flexor sublimis muscle to the interval between the inner condyle and the olecranon. There it passes with the ulnar nerve between the attachments of the flexor carpi ulnaris, and joins the ramifications of the inferior profunda and anastomotic arteries on the inner side of the elbow joint. Some of its offsfets enter the muscles, and others supply the articulation and the ulnar nerve. c. The interosseous branch is a short thick trunk, about an inch long, which is directed backwards towards the interosseus membrane, and divides into anterior and posterior interosseous : these branches will be afterwards followed. ^ d. The metacarpal branch arises from the artery near the lower end of the ulna, and runs along the metacarpal bone of the little finger, of which it is the inner dorsal branch. e. The carpal branches (anterior and posterior) ramify on the front and back of the carpus, on which they anastomose with corresponding offsets of the radial artery, and form arches across the wrist. Peculiarities of the ulnar artery. The origin of the artery may be transferred to any point of the main vessel in the arm or axilla. Once the origin was found between two and three inches below the elbow. (Quain.) When it begins higher than usual it is generally superficial to the flexor muscles at the bend of the elbow (only one exception, Quain), but beneath the aponeurosis of the forearm ; though sometimes it is subcutaneous with the super- ficial veins. The ULNAR NERVE (fig. 81, *) cntcrs the forearm between the attach- ments of the flexor carpi ulnaris to the olecranon and inner condyle of the humerus. Under cover of that muscle the nerve reaches the ulnar artery about the middle (in length) of the forearm, and is continued on the inner side of the vessel to the hand. On the annular ligament the nerve is rather deeper than the artery. It furnishes articular, muscular, and cutaneous branches as below : — a. Articular nerves. In the interval between the olecranon and the inner condyle, slender filaments to the joint arise. h. Muscular branches. It furnishes offsets near the elbow to two muscles of the forearm ; one enters the upper i)art of the flexor carpi ulnaris, and the other supplies the inner half of the flexor profundus digitorum. c. Cutaneous nerve of the forearm and hand. About the middle of the forearm arises a small palmar branch (*), which courses on the ulnar artery, sending twigs around that vessel, to the end in the integuments of the palm of the hand : sometimes a cutaneous ofl'set perforates the aponeu- rosis near the wrist, and joins the internal cutaneous nerve. d. The dorsal cutaneous nerve of the hand arises about two inches above the end of the ulna, and passes obliquely backwards beneath the flexor carpi ulnaris : perforating the aponeurosis it is lost on the back of the hand and fingers (p. 262). The MEDIAN NERVE (fig. 81, ^) leaves the hollow of the elbow between the heads of origin of the pronator teres, and takes the middle line of the limb to the hand. It is placed beneath the flexor sublimis as low as two inches from the annular ligament, where it becomes superficial along the outer border of the tendons of tliat muscle. Lastly the nerve passes be- neath the annular ligament to the palm of the hand. The nerve supplies 270 DISSECTION OF THE FRONT OF THE FOREARM. the muscles on tlie front of the forearm, and furnishes a cutaneous offset to the hand. a. Muscular offsets leave the trunk of the nerve near the elbow, and are distributed to all the muscles of the superficial layer except the flexor carpi ulnaris ; in addition, the nerve supplies the deep layer througli the interosseous branch (p. 271), except the inner half of the flexor profun- dus din^itorum. b. The cutaneous palmar branch (^) arises in the lower fourth of the forearm ; it pierces the fascia near the annular ligament, and crosses over that ligament to reach the palm of the hand. The RADIAL NEKVE is the smaller of the two branches into whicli the musculo-spiral divides at the elbow. This nerve is placed along the outer border of the limb, under cover of the supinator longus (fig. 80), and on the outer side of tlie radial artery till witliin three inclies of the wrist, •where it becomes cutaneous at the posterior border of the supinator tendon. On the surface of the limb it divides into two branches, which are dis- tributed on the dorsum of the hand, and digits (3|^) (p. 2G2). No muscular offset is furnished by the nerve. Dissection (fig. 81). To examine the deep layer of muscles it will be necessary to draw well over to the radial side of the forearm the pronator teres ; to detach the flexor sublimis from tlie radius, and to remove its fleshy part. The areolar tissue is to be taken from the deep muscular fibres ; and the anterior interosseous vessels and nerve, which lie on the interosse- ous membrane, and are concealed by the muscles, are to be traced out. Above the ends of the forearm-bones the arch of the anterior carpal arteries may be defined. Deep Layer of Muscles. Only three deep muscles are present on the front of the forearm. One lies on the ulna, and is the deep flexor of the fingers; a second covers the radius, viz., the long flexor of the thumb; and the third is the pronator quadratus, which lies beneath the other two, near the lower end of the bones. The flexor digitorum profundus vel perforans (fig. 81, ^) arises from the anterior and inner surfaces of the ulna for three-fourths of the length of the bone ; from the inner half of the interosseous ligament for the same distance ; and from an a})oneurosis common to the muscle and the flexor carpi ulnaris. The muscle has a thick fleshy belly, and ends in tendons which, united together, {)ass beneath the annular ligament, and are inserted into the last phalanges of the fingers. The cutaneous surface of the muscle is in contact with the ulnar nerve and vessels, the superficial flexor of the fingers, and the flexor car[)i ulna- ris. The deep surface rests on the ulna and the pronator quadratus mus- cle. The outer border touches the flexor poUicis longus and the anterior interosseous vessels and nerve ; and the inner is connected by aponeurosis to the posterior margin of the ulna. Action. The muscle bends the last joints of the fingers and the wrist ; but it does not act on the last phalanx till after the second has been moved by the flexor sublimis. The fingers are approximated and the joints bent in the following order : — first, the articulation between the metacar[)al and the middle [)halaiix is flexed, secondly, the last phalangeal joint, and thirdly the metacarpo-pha- langeal. The FLEXOR LONGUS POLLicis (fig. 81,^) arises^Yom the hollowed an- terior surface of the radius, as low as the pronator quadratus ; from the DEEP LAYER OF MUSCLES. 271 outer part of the interosseous membrane ; and by a round distinct slip from the coronoid process of the ulna, internal to the attachment of the brachi- alis anticus. Tlie fleshy fibres descend to a tendon, which is continued beneath the annular ligament, and is inserted into the last phalanx of the thumb. On the cutaneous surface of the muscle is the flexor sublimis, with the radial vessels for a short distance inferiorly. The muscle lies on the radius and the pronator quadratus. To tlie inner side is the flexor profundus digitorum. Action. It bends both joints of the thumb, but first the distal or un- gual. After the phalanges are drawn downwards the muscle flexes the wrist. The PRONATOR QUADRATUS (fig. 81, ^) is a flat muscle, and lies on the lower fourth of the bones of the forearm. It arises from the anterior and inner surfaces of the ulna, where it is somewhat widened, and is inserted into the forepart of the radius for about two inches. The anterior surface is covered by the tendons of the flexor muscles of the fingers, and by tlie radial vessels ; and the posterior surface rests on the radius and ulna with the intervening membrane, and on the interosse- ous vessels and nerve. Along its lower borders is the arch formed by the anterior carpal arteries. Action. The end of the radius is moved forwards over the ulna by this muscle, and the hand is pronated. The anterior interosseous artery (fig. 81, e) is continued on the front of the interosseous membrane, between tlie two flexors or in the fibres of the flexor digitorum, till it readies an aperture beneath the pronator quadratus. At that spot the artery turns from the front to the back of the limb, and descends to the back of the carpus, where it ends by anastomosing with the posterior interosseous and carpal arteries. Branches. Numerous offsets are given to the contiguous muscles. a. One long branch (/), median^ accompanies the median nerve, sup- plying it, and either ends in the flexor sublimis, or extends beneath the annular ligament to the palmar arch. h. About the middle of the forearm two nutrient vessels of the radius and ulna arise from the artery. c. Where it is about to pass through the interosseous membrane it fur- nishes twigs to the pronator quadratus ; and one branch is continued be- neath that muscle to anastomose with the anterior carpal arteries. The anterior interosseous nerve is derived from the median (fig. 81, '■^), and accompanies the artery of the same name to the pronator quadratus muscle, the under surface of which it enters. Some lateral branches are distributed by it to the deep flexor muscles. Dissection, The attachment of the biceps and brachialis anticus to the bones of the forearm may be now cleaned and examined. The insertion of the brachialis anticus takes place by a broad thick tendon, about an inch in length, which is fixed into the coronoid process ot the ulna, except at the inner edge ; and into the contiguous rough part o' the bone. Insertion of the biceps. The tendon of the biceps is inserted into the inner part of the tubercle of the radius, and slightly into the bone behind it. A bursa intervenes between it and the forepart of the tubercle. At its attachment the anterior surface becomes external ; and the opposite. The supinator brevis muscle partly surrounds the insertion. 272 DISSECTION OF THE HAND. Section V. THE PALM OF THE HAND. Dissection (fig. 83). The digits being separated and fixed firmly with tacks, the skin is to be reflected from the palm of the hand by means of two incisions. One is to be carried along the centre from the wrist to the fingers ; and the other is to be made from side to side, at the termination of the first. In raising the inner flap, the small pal maris brevis muscle w^ill be seen at the inner margin of the hand ; and its insertion into the skin may be left till the muscle has been learnt. In the fat the ramifica- tions of the small branches (palmar) of the median and ulnar nerves are to be traced. The student should remove the fat from the palmaris muscle, and from the strong palmar fascia in the centre of the hand ; and he should take care not to destroy a transverse fibrous band (transverse ligament) which lies across the roots of the fingers. When cleaning the fat from the palmar fascia he will recognize, near the digits, the digital vessels and nerves ; and must be especially careful of two, — viz., those of the inner side of the lit- tle finger and outer side of the index finger, which appear farther back than the rest, and are most likely to be injured. By the side of the vessels and nerves to the fingers four slender lumbricales muscles are to be defined. Lastly, the skin and the fat may be reflected from the thumb and fingers by an incision along each, in order that the sheaths of the tendons with the collateral vessels and nerves may be laid bare. Cvtaneous palmar nerves. Some unnamed twigs are furnished to the integument from both the median and ulnar nerves in the hand ; and two named cutaneous nerves ramify in the palm. One is an offset of the median nerve (p. 270), and crosses the annular ligament : it extends to about the middle of the palm, and is united with the palmar branch of the ulnar : a few filaments are furnished to the ball of the thumb. The other palmar branch is derived from the ulnar nerve (p. 269) ; it has been traced on the ulnar artery to the hand, and its distribution in the palm may be now observed. The PALMARIS BREVIS (fig. 83, ") is a small subcutaneous muscle, about two inches wide, whose fibres are collected into separate bundles. It is attached on the outer side to the palmar aponeurosis, and its fibres are di- rected inwards to join the skin at the inner border of the hand. This muscle lies over the ulnar artery and nerve. After it has been ex- amined it may be thrown inwards with tlie skin. Action. Drawing inwards the skin of the inner border of the hand to- wards the centre, it deepens the hollow or cup of the palm. The palmar fascia or aponeurosis consists of a central and two lateral parts ; but the lateral, which cover tlie muscles of the thumb and little finger, are so thin as not to require separate notice. The central part is a strong, white layer, which is pointed at the wrist, but is expanded towards the fingers, where it nearly covers the palm of the hand. Posteriorly the fascia receives the tendon of the [)almai'i8 longus, and is connected to the annular ligament ; and anteriorly it ends in four ULNAR VESSELS AND NERVE. 273 Fig. 82. processes, which are continued forwards, one for each finger, to the sheaths of the tendons. At the point of separation of the processes from one an- other some transverse fibres are placed, whicli arch over the lumbricalis muscle, and the digital artery and nerve appearing at this spot. From the pieces of the fascia a few superficial longitudinal fibres are prolonged to the integuments near the cleft of the fingers. Dissection. To follow one of the digital processes of the fascia to its termination, the superficial fibres being first removed, it must be divided longitudinally by inserting the knife beneath it opposite the head of the metacarpal bone. Ending of the processes. Each process of the fascia sends downwards an ofi'set on each side of the tendons, which is fixed to the deep ligament connecting together the ends of the metacarpal bones, and to the edge of the metacarpal bone for a short distance. The superficial transverse ligament of the fingers is a thin fibrous band, which stretches across the roots of the four fingers, and is contained in the fold of skin forming the rudiment of a web be- tween them. Beneath it the digital nerves and vessels are continued onwards to their termina- tions. Sheath of the flexor tendons (fig. 82). Along each finger the flexor tendons are retained in posi- tion against the phalanges by a fibrous sheath. Opposite the middle of each of the two nearest phalanges the sheath is formed by a strong fibrous band (e and^') (ligamentum vaginale), which is almost tendinous in consistence ; but opposite the joints it consists of a thin membrane with scat- tered and oblique fibres. If the sheath be opened it will be seen to be lined by a synovial membrane, which forms long and slender vascular folds (vin- cula vasculosa) between the tendons and the bones. Dissection. The palmar fascia, and the thinner parts of the digital sheaths opposite the joints of the fingers, may be taken away. On the removal of the fascia the palmar arch of the ulnar artery, and the median and ulnar nerves, become ap- parent. Palmar Pakt of the Ulnar Artery (fig. 83). In the palm of the hand the ulnar artery is directed towards the muscles of the thumb, where it communicates with two offsets of the radial trunk, viz., the superficial volar branch (c), and the branch to the radial side of the forefinger (/"). The curved part of the artery, which lies across the hand, is named the superficial palmar arch (d). Its convexity is turned towards the fingers, and its position in the palm would be nearly marked by a line across the hand from the cleft of the thumb. The arch is comparatively superficial ; it is covered in greater part by 18 Thr Ektensor Tendon of the finqer with its ac- cessory mcscles and THE Sheath of thk Flexor Tendons. n. Extensor teadon, with 6, interosseous, and c, lu/n- bricales muscles joining it. d. Flexor tendon; e and/, thicker parts of its sheath. 274 DISSECTION OF THE HAND. the integuments and tlie palmar fascia, but at the inner border of the hand the i)alraaris brevis muscle (iij lies over it. Beneath it are the flexor tendons and the branches of the ulnar and median nerves. Vense comites lie on its sides. Branches. From the convexity of the arch j)roceed the digital arteries, and from the concavity some small offsets to the palm of the hand. A small branch (profunda) arises as soon as the artery enters the hand. a. The profunda or communicating branch (fig. 84, 6), passes down- wards wMth a branch of the ulnar nerve between the abductor and short flexor muscles of the little finger, to inosculate with the deep palmar arch of the radial artery. b. The digital branches (g) are four in number, and supply both sides of the three inner fingers and one side of the index finger. The branch to the inner side of the hand and little finger is undivided ; but the others, corresponding with the three inner interosseous spaces, bifurcate anteriorly to supply the contiguous sides of the above said digits. In the hand these branches are accompanied by the digital nerves, which they sometimes pierce. Near the root of the fingers they receive communicating branches from offsets of the deep arch ; but the digital artery of the inner side of the little finger has its communicatinor branch about the middle of the hand. From the point of bifurcation the branches extend along the sides ot the fingers ; and over the last phalanx the vessels of opposite sides unite in an arch, from whose convexity offsets proceed to supply the ball of the finger. Collateral offsets are furnished to the finger and the sheath of the tendons ; and small twigs are supplied to the phalangeal articulations from small arterial arches on the bones — an arch being close behind each joint. On the dorsum of the last phalanx is another arch near the nail, from which the nail-pulp is supplied. Palmar Part of the Ulnar Nerve (fig. 83, ^). The ulnar nerve divides on or near the annular ligament, into a superficial and a deep branch. The deep branch accompanies the profunda artery to the muscles, and will be subsequently dissected with that vessel (fig. 84). The superficial branch furnishes an offset to the palmaris brevis muscle, and some filaments to the integument of the inner part of the hand, and ends in two digital nerves, for the supply of both sides of the little finger and half the next. Digital nerves (^). The more internal nerve is undivided, like the cor- responding artery. The other is directed to the cleft between the ring and little fingers, and bifurcates for the sujiply of their opposed sides : in the palm of the hand this last branch is connected with an offset (*) of the median nerve. Along the sides of the fingers the digital branches have the same arrangement as those of the median nerve. Palmar Part of the Median Nerve (fig. 83,^). As soon as the median nerve issues from beneath the annular ligament it becomes enlarged and somewhat flattened, and divides into two nearly equal parts for the supply of digital nerves to the thumb and the remaining two fingers and a half: the more external of the two portions furnishes a small muscular branch to the ball of the thumb. The trunk of the nerve and its branches are covered by the palmar fascia ; and beneath them are the tendons of the flexor muscles. MEDIAN NERVE AND BRANCHES 275 «. The branch to muscles of the thumb (*) supplies the outer half of the short flexor, and ends in tlie abductor, and opponens pollicis muscles. b. The digital nerves {^) are five in number. Three of tiiem, which are distributed to the sides of the thumb and the radial side of the fore finger, are undivided, and come from the external of the two pieces into Fig. 83. Dissection of the Superficial Vessels and Nerves of the Palm of the Hand with some OF the Superficial Muscles. Muscles : A. Abductor policis. c. Flexor brevis. D. Adductor policis. H. Palraaris brevis. Arteries: a. Trunk of ulnar, and 6, of radial. c. Superficial volar branch. d. Superficial palmar arch. e. Branch uniting the arch with / the radial digital branch of the forefinger. g. Four digital branches of the superficial arch. (Illustrations of Dissections.) Nerves : 1. Ulnar, and 2, its two digital branches. 3. Median, and 5, its digital branches to three fingers and a half. 4. Branch of the median to some muscles of the thumb 5. Communicating branch from the median to the ulnar. which the trunk of the median splits. The other two spring from the in- ner piece of the nerve, and are bifurcated to supply the opposed sides of the middle and fore, and the middle and ring fingers. The Jirst two nerves belong to the thumb, one being on each side, and the most external is said to communicate with branches of the radial nerve. 276 DISSECTION OF THE HAND. The third is directed to tlie radial side of the index finger, and gives a branch to the most external lumbrical muscle. The fourth furnishes a nerve to the second lumbrical muscle, and di- vides to supply the contiguous sides of the fore and middle fingers. The jijth^ like the fourth, is distributed by two branches to the opposed sides of the middle and ring fingers : it communicates with a branch of the ulnar nerve. On the fingers. On the sides of the fingers the nerves are superficial to the arteries, and reach to the last phalanx, where they end in filaments for the ball and the pulp beneath the nail. In their course forwards the nerves supply chiefly tegumentary branches : one of these is directed backwards by the side of the metacarpal [Jialanx, and after uniting with the digital nerve on the back of the finger (p. 262), is continued to the dorsum of the last phalanx. Dissection. The tendons of the flexor muscles may be followed next to their termination. To expose them the ulnar artery should be cut through below the origin of the profunda branch ; and the small superficial volar branch (of the radial) having been divided, the palmar arch is to be thrown towards the fingers. The ulnar and median nerves are also to be cut be- low the annular ligament, and turned forwards. A longitudinal incision is to be made through tlie centre of the annular ligament, without injuring the small muscles that arise from it, and the pieces of the ligament are to be thrown to the sides. Finally the sheaths of the fingers may be opened for the purpose of ob- serving the insertion of the tendons. Flexor tendons. Beneath the annular ligament the tendons of the deep and superficial flexors are surrounded by a large and loose synovial membrane, which projects upwards into the forearm and downwards into the hand, and sends an oflfset into the digital sheath of the thumb and that of the little finger.^ Flexor sublimis. The tendons of the flexor sublimis are superficial to those of the deep flexor beneath the ligament ; and all four are nearly on the same level, instead of being arranged in pairs, as in the forearm. After crossing the palm of the hand they enter the sheath of the fingers (fig. 82, e), and are inserted each by two processes into the margins of the middle phalanx, about the centre. When first entering the digital sheath, the tendon of the flexor sublimis conceals that of the flexor profundus ; but near the front of the first phalanx it is split for the passage of the tendon of the latter muscle. Dissection. To see the tendons of the deep flexor and the lumbrical mus- cles, the flexor sublimis must be cut through above the wrist, and thrown towards the fingers. Afterwards the areolar tissue should be taken away. Flexor profundus. At the lower border of the annular ligament the ten- dinous mass of the flexor profundus is divided into four pieces, though in the forearm only the tendon of the forefinger is distinct from the rest. From the ligament the four tendons are directed through the hand to the fingers, and give origin to the small lumbricales muscles. At the root of the fingers each enters the digital sheath with a tendon of the flexor sub- limis, and having passed through that tendon, is inserted into the base of the last phalanx. ' Theile refers the notice of this fact to M. Maslieurat-Lagdmard, in No. 18 of the "Gazette M^dicale," for 1839. MUSCLES OF THUMB. 277 Between both flexor tendons and the bones are thin membranes, one for each. By means of this each tendon is connected with the capsule of the joint, and the fore part of the phahinx immediately behind the bone into which it is inserted. The himhricales muscles (fig. 84, i) are four small fleshy slips, which arise from the tendons of the deep flexor near the annular ligament ; and are directed to the radial side of each finger, to be inserted into an aponeurotic expansion on the dorsal aspect of the metacarpal phalanx (fig. 82, c). Ttiese muscles are concealed for the most part by the tendons and ves- sels that have been removed; but they are subcutaneous for a short distance between the processes of the palmar fascia. The outer two arise from single tendons, but each of the others is connected with two tendons. Action. By their insertion into the long extensor tendon they will aid it in straightening the two last phalangeal joints ; and when the metacarpo- phalangeal joints are much bent they may assist in maintaining the flexion of these articulations. Tendon of the flexor poUicis longus. Beneath the annular ligament this tendon is external to the flexor profundus, and turns outwards between the heads of the flexor brevis poUicis (fig. 84), to be inserted into the last phalanx of the thumb. The common synovial membrane surrounds it be- neath the annular ligament, and sends a prolongation, as before said, into its digital sheath. Dissection (fig. 84). The deep palmar arch of the radial artery, with the deep branch of the ulnar nerve, and the interossei muscles, will come into view if the flexor profundus is cut above the wrist, and thrown with the lumbricales muscles towards the fingers ; but in raising the tendons the student should preserve two fine nerves and vessels entering the two inner lumbrical muscles. The dissection of the muscles of the ball of the thumb and the little finger is next to be prepared. Some care is necessary in making a satis- factory separation of the ditferent small thumb muscles ; but those of the little finger are more easily defined. Short Muscles of the Thumb (fig. 84). These are four in number, and are named from their action on the thumb. The most superficial is the abductor pollicis ; beneath it is the opponens pollicis, which will be recognized by its attachment to the whole length of the metacarpal bone. To the inner side of the last is the short flexor. And the wide muscle coming from the third metacarpal bone is the adductor of the thumb. The ABDUCTOR POLLICIS, A, is about an inch wide, and is thin, and superficial to the rest. It «nses from the upper part of the annular liga- ment at the radial side, and from the ridge of the os trapezium ; and is inserted into the base of the first phalanx of the thumb. The muscle is subcutaneous, and rests on the opponens pollicis : it is connected oftentimes at its origin with a slip from the tendon of the ex- tensor ossis metacarpi pollicis. Action. It removes the metacarpal bone of the thumb from the other digits ; and when it has so acted it may assist slightly the short flexor in bending the metacarpo-phalangeal joint. Dissection. The opponens pollicis will be seen on cutting through the abductor. To separate the muscle from the short flexor on the inner side, the student should begin near the fore part of the metacarpal bone, where there is usually a slight interval. 278 DISSECTION OF THE HAND. The orpoNENS pollicis, b, arises from the annular ligament beneath the preceding, and from the os trapezium and its ridge ; it is inserted into the front and outer border of the metacarpal bone for the whole length. This muscle is partly concealed by the preceding, though it projects on the outer side. Along its inner border is the flexor brevis pollicis. An insertion into the external sesamoid bone is described by Theile. Action, From its attachment to the metacarpal bone it is able to draw that bone inwards over the palm of the hand, turning it at the same time, so as to allow the ball of the thumb to be applied to the ball of each of the fingers, as in picking up a pin. The FLEXOR BREVIS POLLICIS, c, is the largest of the short muscles of the thumb : it consists of two pieces (inner and outer) at the insertion, but these are united at the origin. Posteriorly it arises from the os trapezoides and OS magnum ; from the bases of the second and third metacarpal bones ; and from the annular ligament, at the lower part. In front it is inserted by two heads into the sides of the base of the first phalanx of the thumb, — the inner piece being united with the adductor, and the outer with the abductor pollicis. A sesamoid bone is connected with each head at its insertion. The tendon of the long flexor lies on this muscle, occupying the interval between the processes of insertion ; and the deep palmar arch of the radial artery issues from beneath the inner head. Action. The muscle bends the metacarpo-phalangeal joint, and assists the opponens in drawing the thumb forwards and inwards over the palm. The ADDUCTOR POLLICIS, D, is pointed at the thumb, and wide at the opposite end. Its origin is fixed to the anterior or lower two-thirds of the metacarpal bone of the middle digit, on the palmar aspect ; and its inser- tion is attached, with that of the short flexor, to the inner side of the first phalanx of the thumb. The cutaneous surface is in contact with the .tendons of the flexor pro- fundus and the lumbrical muscles ; and the deep surface lies over (in this position) the first dorsal interosseous muscle, j, and the second and third metacarpal bones with the intervening muscle. Actions. By its contraction the thumb is applied to the radial border of the hand, and approximated to the fingers. Short Muscles of the Little Finger (fig. 84). There are com- monly two muscles in the ball of the little finger, — an abductor and an adductor. Sometimes there is a short flexor between the other two. The abductor minimi digiti, e, is the most internal of the short muscles. It arises from the pisiform bone and the tendon of the flexor carpi ulnaris, and is inserted into the ulnar side of the base of the first phalanx of the little finger; an oft'set from it reaches the extensor tendon on the back of the phalanx. The palmaris brevis partly conceals the muscle. Action. First it draws the little finger away from the others ; but con- tinuing to act it bends the metacarpo-phalangeal joint. The FLEXOR brevis minimi digiti, f, appears often to be a part of the abductor. Placed at the radial border of the preceding muscle, it takes origin from the tip of the process of tiie unciform bone, and sliglitly from the annular ligament ; it is inserted with the abductor into the first phalanx. It lies on the adductor ; and near its origin it is separated from the abductor muscle by the deep branches of the ulnar artery and nerve. MUSCLES OF LITTLE FINGER, 279 Action. The first phalanx is moved towards the palm by this muscle, and the metacarpo-phalangeal joint is bent. The ADDUCTOR vel opponens minimi digiti, g, resembles the opponens poUicis in being attached to the metacarpal bone. Its origin is from the process of the unciform bone, and the lower part of the annular ligament ; its insertion is fixed into the ulnar side of the metacarpal bone of the little finger. Fig. 84. Deep Dissection of the Palm of the Hand. (Illustrations of Dissectioas.) fuscles : A. Abductor pollicis. B. Opponens pollicis. c. Flexor brevis pollicis. D. Adductor pollicis. B. Abductor minimi digiti. P. Flexor brevis minimi digiti. Q. Opponens minimi digiti. I. Lmnbricales. J. First dorsal interosseous. Vessels : a. Ulnar artery, cut. 6. Profunda branch. e. Deep palmar arch. d. Radial digital artery of the index finger. e. Arteria magna pollicis. /. Interosseous arteries. Nerves : 1. Ulnar nerve, cut. 2. Deep branch of the palm of the hand, and 4, its continuation to end in some of the thumb muscles. 3. Offsets to the inner two lumbricales. The adductor is partly overlaid by the preceding muscles ; and beneath it the deep branches of the ulnar artery and nerve pass. Action. It raises the inner metacarpal bone, and moves it towards the others, so as to deepen the palm of the hand. Dissection. The radial artery comes into the hand between the first 280 DISSECTION OF THE HAND. two metacarpal bones ; and to lay bare the vessel, it will be requisite to detach the orij2!;in of the flexor brevis pollicis. The deep palmar arch, and the branch of the ulnar nerve accompanying it, together with their offsets, are to be dissected out. A fascia, which covers the interossei muscles, is to be removed, when the dissector has observed its connection with the transverse ligament uniting the heads of the metacarpal bones. Radial Artery in the Hand (llg. 84). The radial artery enters the palm at the first interosseous space, between the heads of the first dorsal interosseous muscle : and after furnishing one branch to the thumb, and another to the index finger, turns across the hand towards the ulnar side, with its venae comites, forming the deep arch. The deep palmar arch (c) extends from the interosseous space to the base of the metacarpal bone of the little finger, where it joins the profunda communicating branch (6). Its convexity, which is but slight, is directed forwards ; and its position is nearer the carpal bones than that of the superficial arch. The arch has a deep position in the hand, and lies on the metacarpal bones and the interossei muscles. It is covered by the long flexor tendons, and in part by the flexor brevis pollicis. The branches of the arch are the following : — a. Recurrent branches pass from the concavity of the arch to the front of the carpus ; these supply the bones, and anastomose with the other carpal arteries. b. Three perforating arteries pierce the three inner dorsal interossei muscles, and communicate with the interosseous arteries on the back of the hand. c. Usually there are three palmar interosseous arteries (/), which occupy the three inner metacarpal spaces, and terminate by joining the digital branches of the superficial palmar arch at the cleft of the fingers. These branches supply the interosseous muscles, and the two or three inner lumbricales ; they vary much in their size and distribution. d. Digital branches of the radial. The large artery of the thumb (^) (art. princeps pollicis) runs between the first metacarpal bone and the flexor brevis pollicis, to the interval between the heads of the muscle, where it divides into the two collateral branches of the thumb : these are distributed like the arteries of the superficial arch. e. The digital branch of the index finger {d) (art. radialis indicis) is directed over the first dorsal interosseous muscle, .i, and beneath the short flexor and the adductor pollicis, to the radial side of the forefinger. At the free or anterior border of the adductor pollicis, d, this branch is usually connected by an offset with the superficial palmar arch ; and at the end of the digit it unites with the branch furnished to the 0})posite side by the ulnar artery. The deep branch of the ulnar nerve {^^ accompanies the arch of the radial artery as far as the muscles of the thumb, and terminates in oflTsets to the adductor pollicis and the inner head of the short flexor. Branches, Near its origin the nerve furnislies branches to the muscles of the little finger. In the palm it gives offsets to all the palmar and dorsal interosseous muscles, and to the inner two lumbrical muscles ('), besides the terminal branches before mentioned. The transverse metacarpal ligament connects togetlier the heads of the four inner metacarpal bones. Its cutaneous surface is hollowed where the flexor tendons cross it ; and beneath the interossei nmscles pass to their RADIAL ARTERY AND OFFSETS. 281 insertion. To the posterior border tlie fascia covering tlie interossei muscles is united. The ligament should now be taken away to see the interossei muscles. The INTEROSSEI MUSCLES, SO named from their position between the metacarpal bones, are seven in number. Two muscles occupy each space, except in the first where there is only one ; they arise from the meta- carpal bones, and are inserted into the first phalanx of the fingers. They are divided into palmar and dorsal interossei ; but all the small muscles are evident in the palm of the hand, though some project more than the others. The palmar muscles (fig. 85), three in number, are smaller than the dorsal set, and are most prominent in the palm of the hand. They arise from the palmar surface of the metacarpal bones of the fingers on which they act, viz., those of the fore, ring, and little fingers; and they are in- serted into the ulnar side of the fore, and the radial side of the other two digits. Fig. 85. Fig. 86. Three Palmar Interosseous Musclks. a. Muscle of the little finger; b, of the rins finger; and c, of the forefinger. Four Dorsal Interosseous Musclks. d. Muscle of the forefinger, called sometimes abductor indicia. e and/. Muscles of the middle finger. g. Muscle of the ring finger. Both sets of muscles have a similar termination (fig. 82, b) : — the fibres end in a tendon, which is inserted into the side of the first or metacarpal phalanx, and sends an expansion to join the extensor tendon on the dor- sum of the bone. The dorsal interossei (fig. 86) extend farther back than the palmar set, and arise by two heads from the lateral surfaces of the metacarpal bones between which they lie. The dorsal muscles are thus allotted to the digits : — two belong to the second finger, a third is connected with the radial side of the fore, and the fourth with the ulnar side of the ring finger. Action, They help to bend the metacarpo-phalangeal joints by their 282 DISSECTION OF THE FOREARM. attachment to the first phalanx ; and assist in the extension of the two last phalangeal joints through tiieir union with the extensor tendon. F'urther they can separate and approximate the fingers : thus the palmar set adduct to the second finger ; and the dorsal abduct from the middle line of the second finger — the two attached to this digit moving it to the right and left of that line. Dissection. The attachments of the annular ligament to the carpal bones on each side are to be next dissected out by taking away the small muscles of the thumb and little finger. Before reading its description, the ends of the cut ligament irniy be placed in apposition. The anterior annular ligament is a firm ligamentous band, which arches over and binds down the flexor tendons of the fingers. It is attached ex- ternally to the front of the os scaphoides, and to the fore and inner parts, and ridge of the os trapezium ; and internally to the unciform and pisiform bones. By its upper border it is connected with the aponeurosis of the forearm ; and by its anterior surface it joins the palmar fascia. On it lie the palmaris longus and the ulnar artery and nerve. Dissection. Next follow the tendon of the flexor carpi radialis through the OS trapezium to its insertion into the metacarpal bones. The tendon of the flexor carpi radialis, in passing from the forearm to the hand, lies in the groove in the os trapezium between the attachments of the annular ligament to the bone, but outside the arch of that ligament ; here it is bound down by a fibrous sheath lined by a synovial membrane. The tendon is inserted into the base of the metacarpal bone of the index finger, and sends a slip to that of the middle digit. Section VI. THE BACK OF THE FOREARM. Position. During the dissection of the back of the forearm the limb lies ■with the forepart undermost, and a small block is to be placed beneath the wrist for the purpose of stretching the tendons. Dissection (fig. 87). The fascia and the cutaneous nerves and vessels are to be reflected from the muscles of the forearm, and from the tendons on the back of the hand ; but in removing the fascia in the forearm, the student must be careful not to cut away the posterior interosseous vessels, which are in contact with it on the inner side in the lower third. A thick- ened band of the fascia opposite the carpus (the posterior annular ligament) is to be left. Let the integument be removed from the fingers, in order that the ten- dons may be traced to tlie end of the digits. The several muscles should be separated from one another up to their origin, especially the two radial extensors of the wrist. The posterior annular ligament, k, consists of the special aponeurosis of the limb, thickened by the addition of some transverse fibres, and is situate opposite the lower end of the l>ones of the forearm. This band is connected at the outer part to the radius, and at the inner to the cuneiform and pisiform bones. Processes from it are fixed to the bones beneatii, and SUPERFICIAL LAYER OF MUSCLES 283 confine the extensor tendons. The ligament will be subsequently examined more in detail. Superficial layer of muscles (fig. 87). The muscles are arranged in a superficial and a deep layer, as on the anterior part of the forearm. Fiff. 87. Mttscles : A. Supinator longus. B. Extensor carpi radialis longus. 0. Extensor carpi radialis breris. D. Extensor communis digitorum. B. Extensor minimi digiti. P. Extensor carpi ulnaris. G. Anconeus. H. Extensor ossis metacarpi pollicis. 1. Extensor primi iiiternodii. J. Extensor secundi internodii pollicis. K. Posterior annular ligament. L. Bands uniting the tendons of the common ex- tensor on the back of the hand. N. Insertion of the common extensor into the last two phalanges. Arteries : a. Posterior interosseous. 1. Radial. 2. Posterior carpal arch. d. Metacarpal branch. 4. Dorsal branche.s of thumb and forefinger. Superficial Layer of Mcsct.es on the Back op the Forearm, with some Vessels. (Illustrations of Dissections.) The superficial layer contains seven muscles, which arise mostly by a com- mon tendon from the outer condyle of the humerus, and liave tlie under- mentioned position one to another from without inwards ; — the long supi- 284 DISSECTION OF THE FOREARM. nator, a, the two radial extensors of* the wrist, b and c (long and short), the common extensor of the fingers, d, the extensor of the little finger, e, and the ulnar extensor of the wrist, f. There is one other small muscle near the elbow, the anconeus, G. The SUPINATOR RADII LONGUS, A, reachcs upwards into the arm, and limits on the outer side the hollow in front of the elbow. The muscle arises from the upper two-thirds of the outer condyloid ridge of the hu- merus, and the front of the external intermuscular septum. The fleshy fibres end about the middle of the forearm in a tendon, which is inserted into the lower end of the radius, close above the styloid process. In the arm the margins of the supinator are directed towards the sur- face and the bone, but in the forearm and muscle is flattened over the others, with its edges forwards and backwards. Its anterior border touches the biceps and the pronator teres ; and the posterior is in contact with both radial extensors of the wrist. Near its insertion the supinator is covered by two extensors of the thumb. Beneath the muscle are the brachialis anticus and musculo-spiral nerve, the extensors of the wrist, the radial vessels and nerve, and the radius. Action. The chief use of this supinator is to bend the elbow-joint. But if the radius is either forcibly pronated or supinated the muscle can put the hand into a state intermediate between pronation and supination, — the thumb being brought above the forefinger. If the radius is fixed as in climbing, the muscle will bring up the hu- merus, bending the elbow. The EXTENSOR CARPI RADiALis LONGiOR, B, arises fVom the lower third of the outer condyloid ridge of the humerus, and the front of the contigu- ous intermuscular septum ; and from the septum between it and the next muscle. The muscle lies on the short radial extensor, being partly cov- ered by the supinator longus ; and its tendon passes beneath the extensors of the thumb, and the annular ligament, to be inserted into the base of the metacarpal bone of the index finger. Along its outer border lies the radial nerve. Action. The long extensor straightens first the wrist, and bends next the elbow joint. If the hand is fixed in climbing, it will act on the humerus like the long supinator. The EXTENSOR CARPI RADIALIS BREViOR, c, is attached to the outer condyle of the humerus by a tendon common to it and the three following muscles, viz., common extensor of the fingers, extensor of the little finger and ulnar extensor of the wrist : it takes origin also from the capsular ligament of the elbow joint. The tendon of the muscle is closely con- nected with the preceding, and after passing with it through the same com- partment of the annular ligament, is inserted into the base of the meta- carpal bone of the middle finger. Concealed on the outer side by the two preceding muscles this extensor rests on the radius and some of the muscles attached to it, that is to say, on the supinator brevis, and the pronator teres. Along the ulnar side is the common extensor of the fingers; and the extensors of the thumb come between it and the digital extensor. Both radial extensors of the carpus have usually a bursa at the insertion. Action. This muscle resembles its fellow in extending the wrist, but differs from it in extendin"; the elbow. EXTEN'SORS OF DIGITS. 285 Acting with the long extensor of the wrist it will move the lower end of the radius in supination. The EXTENSOR COMMUNIS DiGiTORUM, D, is single at its origin, but is divided inferiorly into four tendons. It arises from the common tendon, from aponeurotic septa between it and the muscles around, and from the aponeurosis of the limb. Near the lower part of the forearm the muscle ends in three tendons, which pass through a compartment of the annular ligament with the indicator muscle; below the ligament, the most internal tendon divides into two, and all four are directed along the back of the hand to their insertion into the two last phalanges of the fingers. On the back of the fingers the tendons have the following arrangement. On the dorsum of the first phalanx each forms an expansion with the ten- dons of the lumbricales and interossei muscles (fig. 82). At the front of that phalanx it divides into three parts (fig. 87, ^) : — the central one is fixed into the base of the second phalanx, whilst the lateral pieces unite, and are inserted into tlie base of the last phalanx. On the fore and little fingers the expansion is joined by the special tendons of those digits ; and oppo- site the first two articulations of each finger the tendon sends down lateral bands to join the capsule of the joint. Tliis muscle is placed between the extensors of the wrist and little finger, and conceals the deep layer. On the back of the hand the tendons are joined by cross pieces, l, wliich are strongest between the ring finger ten- don and its collateral tendons ; they prevent the ring finger being raised if the others are closed. Action. The muscle straightens the three phalanges of the fingers from root to tip, and separates the four digits from each other. It can extend tiie nearest joint of each finger whilst the two farthest are kept bent by the flexors ; and it can straighten the last two articulations when the nearest is bent. The digits being straightened, it will assist the other muscles in extend- ing the wrist and the elbow. The EXTENSOR MINIMI DiGiTi, E, is the most slender muscle on the back of the forearm, and appears to be but a part of the common extensor. Its origin is in common with that of the extensor communis, but it passes through a distinct sheath of the annular ligament. Beyond the ligament the tendon splits into two, and only one unites by a cross piece with the tendon of the common extensor : both finally join the common expansion on the first phalanx of the little finger. Action. It extends the little finger and moves back the wrist and elbow. As the inner piece of the split tendon is not united with the common ex- tensor it can straighten the digit during flexion of tlie other fingers. The EXTENSOR CARPI ULNARis MUSCLE, F, aHscs from the common tendon, and the aponeurosis of tlie forearm ; it is also fixed by fascia to the posterior border of the ulna below the anconeus muscle (about the middle third). Its tendon becomes free from flesliy fibres near the annu- lar ligament, and passes tiirough a separate sheath in that structure to be inserted into the base of the metacarpal bone of the little finger. Beneath this extensor are some of the muscles of the deep layer, with part of the ulna. On the outer side is the extensor of the little finger, with the posterior interosseous vessels. Action. As the name expresses, the muscle puts back the wrist and in- clines the hand towards the ulnar side : it can then extend the elbow joint. The ANCONEUS, G, is a small triangular muscle near the elbow. It arises 286 DISSECTION OF THE FOREARM, from the outer condyle of the humerus by a tendon distinct from, and on the uhiar side of the common tendon of origin of tlie other muscles. From this origin the fibres diverge to tlieir insertion into the outer side of the olecranon, and into the impression on the upper third of the posterior sur- face of the ulna. Fij Muscles : A. Supinator longus, B. and c. Kadial extensors of the cai'pus, cut. D. Supinator brevis. E. Extensor ossis metacarpi pollicis. F. Extensor primi internodii. 0. Extensor secundi internodii. H, Extensor iudicis. 1. Posterior annular ligament. Arte-ries : a. Posterior interosseous. 6. Recurrent interosseous. c. Dorsal part of the anterior interosseous. d. Dorsal part of the radial. €. Dorsal branches to the thumb and forefinger. /. Dorsal carpal arch. ff. Two posterior interosseous (ulnar) of the hand. Nerves : 2. Radial. 3. Posterior interosseous at its origin, and 4, near its ending in a swelling on the back of the carpus. Dissection of the Deep Later of Mcscles, and the VEasELS anp Nerve on the Back op THK Forearm. (Illustrations of Dissections.) The upper fibres are nearly transverse, and are contiguous to the lowest of the triceps muscle. Beneath the anconeous lie llie supinator brevis muscle, and the recurrent interosseous vessels. Action. Commonly it acts on the ulna, and assists the triceps in ex- tending the elbow. DEEP EXTENSOR MUSCLES. 287 Dissection (fig. 88). For the display of the deep muscles at the back of the forearm, and tlie posterior interosseous artery and nerve, three of the superficial muscles, viz., extensor communis, extensor minimi digiti, and extensor carpi ulnaris, are to be detached from their origin and turned aside : in this proceeding the small branches of the nerve and artery enter- ing the muscles may be divided. The loose tissue and fat are then to be removed from the muscles, and the ramifications of the artery and nerve ; and a slender part of the nerve, which sinks beneath the extensor of the second phalanx of the thumb about the middle of the forearm, should be traced beyond the wrist. The separation of the muscles should be made carefully, because the highest two of the thumb are not always very distinct from each other. Deep layer of muscles (fig. 88). In this layer there are five small muscles, viz., one supinator of the forearm, and four special extensor mus- cles of the thumb and forefinger. The highest muscle, surrounding partly the upper end of the radius, is the supinator brevis, d. Below this are the three muscles of the thumb in the following order : — the extensor of the metacarpal bone, e, the extensor of the first, f, and that of the second phalanx, o. On the ulna the indicator muscle, h, is placed. The EXTENSOR ossis METACARPi poLLicis, E, is the largest and highest of the extensor muscles of the thumb, and is sometimes united with the supinator brevis. It arises from the posterior surface of the radius for three inches below the supinator brevis ; from the ulna for the same dis- tance by a narrow special impression on the upper and outer part of the posterior surface ; and from the intervening interosseous membrane. The tendon is directed outwards over the radial extensors of the wrist, and through the annular ligament, to be inserted into the base of the metacarpal bone of the thumb, and by a slip into the os trapezium. The muscle is concealed at first by the common extensor of the fingers ; but it becomes cutaneous between the last muscle and the extensors of the wrist, about two inches above the end of the radius (fig. 87). Opposite the carpus the radial artery winds backwards beneath its tendon. Between the contiguous borders of this muscle and the supinator brevis the posterior interosseous artery (a) appears. Action. By this muscle the thumb is moved backwards from the palm of the hand, and the wrist is extended on the radial side. The EXTENSOR PRiMi iNTERNODii POLLICIS, F, is the Smallest muscle of the deep layer, and its tendon accompanies that of the preceding ex- tensor. Its origin, about one inch in width, is from the radius and the interosseous membrane, close below the attachment of the preceding muscle. The tendon passes through the same space in the annular ligament as the extensor of the metacarpal bone, and is inserted into the metacarpal end of the first phalanx of the thumb. With respect to surrounding parts this muscle has the same connections as the preceding. Action. It extends first the nearest phalanx, and then the wrist, like its companion. The EXTENSOR SECUNDi INTERNODII POLLICIS, G, ariscs from the ulna for four inches below the anconeus, along the ulnar side of the extensor of the metacarpal bone ; and from the interosseous membrane, below, for one inch. Its tendon passing through a sheath in the annular ligament, dis- tinct from that of the other two extensor muscles, is directed along the dorsum of the thumb to be fixed to the base of the last phalanx. It is covered by the same muscles as the other extensors of the thumb, 288 DISSECTION OF THE FOREARM. but it becomes superficial nearer the lower end of the radius. Below the annular ligament its tendon crosses the radial artery, and the extensors of the wrist. Action. Its use is similar to that of the extensor of the first phalanx. When the phalanges are straight, the two extensors will assist in carrying back the metacarpal bone. The EXTENSOR iNDicis, H (indicator), arises from the ulna for tliree or four inches, usually beyond the middle, and internal to the preceding mus- cles ; and from the interosseous ligament below. Near the annular liga- ment the tendon becomes free from muscular fibres, and passing through that band witli the common extensor of the fingers, is applied to, and blends with, the external tendon of that muscle in the expansion on the phalanx of the forefinger. Until this muscle has passed the ligament it is covered by the superfi- cial layer, but it is afterwards subaponeurotic. Action. The muscle can point the fore finger even when the three inner fingers are bent, inclining it towards the others at the same time. And it will help the common extensor of the digits in pulling back the hand. Dissection. To lay bare the supinator brevis, it will be necessary to detach the anconeus from the external condyle ot the humerus, and to cut through the supinator longus and the radial extensors of the wrist. After those muscles have been divided, the fleshy fibres of the supinator are to be followed forwards to their insertion into the radius ; and that part of the origin of the flexor profundus digitorum, which lies on the outer side of the insertion of the brachialis anticus, is to be removed. The SUPINATOR BREVIS, D, surrounds the upper part of the radius, except at the tubercle and along a slip of bone below it. It arises from a depression below the small sigmoid cavity of the ulna, from the external margin of the bone for two inches below that pit, and from the orbicular ligament of the radius and the external lateral ligament of the elbow joint. The fibres i)ass outwards, and are inserted into the upper third or more of the radius, except at the inner part, reaching downwards to the insertion of the pronator teres, and forw^ards to the hollowed anterior surface. The supinator is concealed altogether at the posterior and external aspects of the limb by the muscles of the superficial layer; and anteriorly the radial vessels and nerve lie over it. The lower border is contiguous to the extensor ossis metacarpi pollicis, only the posterior interosseous artery (a) intervening. Through the substance of the muscle the posterior interosseous nerve (") winds to the back of the limb. Action. When the radius has been moved over the ulna as in prona- tion, the short supinator comes into play to bring that bone again to the outer side of the ulna. The posterior interosseous artery (fig. 88, a) is an offset from the com- mon interosseous trunk (p. 269), and reaches the back of the forearm above the ligament between the bones. Appearing between the contiguous borders of the supinator brevis and extensor ossis metacarpi, the artery descends at first between the superficial and deep layers of muscles ; and afterwards, with a superficial position in the lower third of the forearm, along the tendon of the extensor carpi ulnaris as far as the wrist, where it ends by anastomosing with the carpal and anterior interosseous arteries. It furnishes muscular offsets to the contiguous muscles, except the two or three outer ; and the following recurrent branch: — The recurrent branch {h) springs from the artery near the commence- RADIAL ARTERY. 289 ment, and ascends on or tlirougli the fibres of the supinator, but beneath the anconeus, to supply both those muscles and the elbow joint, and to anastomose with the superior profunda artery in the last-named muscle, as well as with the recurrent radial. The posterior interosseous nerve (') takes origin from the musculo-spiral trunk (p. 259), and winds backwards through the fibres of the supinator brevis. Escaped from the supinator, the nerve is placed between the superficial and deep layers of muscles as far as the middle of the forearm. Much reduced in size at that spot, it sinks beneath the extensor of the second phalanx of the tliumb, and runs on the interosseous membrane to the back of tlie carpus. Finally the nerve enlarges beneath the tendons of the extensor communis digitorum, and terminates in filaments to the ligaments and the articulations of the carpus. Branches. It furnishes offsets to all the muscles of the deep layer ; and to those of the superficial layer with the exception of the three follow- ing, viz., anconeus, supinator longus, and extensor carpi radialis longior. Radial Artery at the Wrist (fig. 88). The radial artery (c?), with its venae comites, winds below the radius to the back of the carpus, and enters the palm of the hand at the first interosseous space, between the heads of the first dorsal interosseous muscle. At first the vessel lies deeply on the external lateral ligament of the wrist joint, and beneath the tendons of the extensors of the metacarpal bone, e, and first phalanx of the thumb, f ; but afterwards it is more superficial, and is crossed by the tendon of the extensor of the second phalanx of the thumb, g. Offsets of the external cutaneous nerve entwine around the artery, and the radial nerve is superficial to it. Its branches are numerous but incon- siderable in size: — a. The dorsal carpal branch (f) passes transversely beneath the ex- tensor tendons, and forms an arch with a corresponding oflTset of the ulnar artery ; with this arch the posterior interosseous artery joins. From the carpal arch branches (g) descend to the third and fourth interosseous spaces, and constitute two of tlie three dorsal interosseous arteries: at the cleft of the fingers each divides into two, which are con- tinued along the dorsum of the digits. In front they communicate with the digital arteries ; and behind they are joined by the perforating branches of the palmar arch. b. The metacarpal or Jlrst dorsal interosseous branch (fig. 87, b), reaches the space between the second and third metacarpal bones, and anastomoses, like the corresponding arteries of the other spaces, with a perforating branch of the deep palmar arch. Finally it is continued to the cleft of the fingers, where it joins the digital artery of the. superficial palmar arch, and gives small dorsal branches to the index and second fingers. c. Two small dorsal arteries of the thumb (c) arise opposite the meta- carpal bone, along which they extend, one on each border, to be distributed on its posterior aspect. d. The dorsal branch of the index finger is distributed on the radial edge of that digit. The ditferent compartments of the annular ligament may be seen more completely by dividing the sheaths of the ligament over the several ten- dons passing beneath. Tliere are six different spaces, and each is lubri- cated by a synovial membrane. The most external one lodges the first two extensors of the thumb. The next is a large hollow for the two radial 19 290 DISSECTION OF THE UPPER LIMB. extensors of the wrist ; and a very small space for the extensor of the second phalanx of the thumb follows on the ulnar side. Farther to the inner side is the common sheath for the extensor of the fingers, and tliat of the fore finger ; and then comes a separate compartment for the exten- sor of the little finger. Internal to all is the space for the extensor carpi ulnaris. The last muscle grooves the ulna ; but the others lie in hollows in the radius in the order mentioned above, with the exception of the ex- tensor minimi digiti, which is situate between the bones. Dissection. If the supinator brevis be divided by a vertical incision, and reflected from the radius, its attachment to the bone will be better understood. The posterior interosseous nerve, and the offsets from its gangliform enlargement, may be traced more completely after the tendons of the ex- tensor of the fingers and indicator muscle have been cut at the wrist. The dorsal surface of the posterior interossei muscles of the hand may be cleaned, so that their double origin, and their insertion into the side, and on the dorsum of the phalanges, may be observed. Between the heads of origin of these muscles the posterior perforating arteries appear. Section VII. ligaments of the shoulder, elbow, wrist, and hand. Directions. The ligaments of the remaining articulations of the limb, which are still moist, may be examined at once ; but if any of them have become dry, they may be softened by immersion in water, or with a wet cloth, whilst the student learns the others. Dissection. For the preparation of the external ligaments of the shoulder-joint the tendons of the surrounding muscles, viz., subscapularis, supra and infraspinatus, and teres minor, must be detached from the cap- sule ; and as these are united with it, some care will be needed not to open the joint. Shoulder Joint. This ball and socket joint (fig. 89) is formed be- tween the head of the humerus and the glenoid fossa of the scapula. In- closing the articular ends of the bones is a fibrous capsule lined by a syno- vial membrane. A ligamentous band (glenoid ligament) deepens the shallow scapular cavity for the reception of the large head of the humerus. The bones are but slightly bound together by ligamentous bands, for, on the removal of the muscles, the head of the humerus may be drawn from the scapula for the distance of an inch. The capsular ligament (fig. TT), *) surrounds loosely the articular ends of the bones ; it is thickened above and below, and receives fibres from the contiguous tendons. At the upper edge it is fixed around the articular surface of the scapula, where it is connected with the long head of the triceps. At the lower edge the ligament is fixed (fig. 89) to the neck of the. humerus close to the articular surface above, but at a little distance therefrom below ; and its continuity is interrupted between the tuberosities (ft) by the tendon of the biceps muscle, over which it is continued along the bicipital groove (fig. 7o). On the inner side there is generally an aperture in the LIGAMENTS OF SHOULDER 291 capsule, below the coracoid process, through which the synovial mem- brane of the joint is continuous with the bursa beneath the tendon of the subscapularis. Tlie following muscles surround the articulation : above and behind are the supraspinatus, infraspinatus, and teres minor ; below, the capsule is only partly covered by the subscapularis ; but internally it is well sup- ported by the last-named muscle. On the front of the capsule is a rather thick band of fibres — the coraco- humeral or accessory ligament (fig. 75, ^), which springs from the base of the coracoid process of the scapula, and widening over the front of the joint, is attached to the margins of the bicipital groove, and to the tube- rosities. Dissection. To see the interior of the articulation, cut circularly through the capsule near the scapula. When this has been done the attachment of the capsule to the bones, the glenoid ligament, and the tendon of the biceps will be manifest. The tendon of the biceps muscle arches over the head of the humerus, and serves the purpose of a ligament in restraining the upward and out- ward movements of that bone. It is attached to the upper part of the glenoid fossa of the scapula (fig. 89, d), and is united on each side with the glenoid ligament. At first flat, it afterwards becomes round, and en- tering the groove between the tuberosities of the humerus, it is surrounded by the synovial membrane. Fig. 89. View op the Interior of the Shoclder-joint. c. Glenoid ligament around the glenoid fossa. a. Attachment of the capsule to the neck of the humerus. 6. Interval of the bicipital groove. d. Tendou of the biceps fixed to the top of the fossa. The glenoid ligament (fig. 89, c) is a firm fibro-cartilaginous band, which surrounds tiie fossa of the same name, deepening it for the reception of the head of the humerus. It is about two lines in depth, and is con- nected in part with the sides of the tendon of the biceps ; but most of its fibres are fixed separately to the margin of the glenoid fossa. The synovial membrane lines the articular surface of the capsule, and is continued through the aperture on the inner part to join the bursa beneath the subscapular muscle. Tiie membrane is reflected around the tendon of the biceps, and lines the bicipital groove of the humerus. 292 DISSECTION OF THE UPPER LIMB. Articular surfaces (fig. 89). The convex articular head of the humerus is two or three times larger than tlie hollow in the scapula, and forms rather less than the half of a sphere. The head of the bone is joined to the shaft at an angle as it is in the femur, and a rotatory movement is pos- sessed by the humerus in consequence. The glenoid surface of the scapula is oval in form with the large end down, and is very shallow ; it is not large enough to cover the head of the humerus. Movements. In this joint there is the common motion in four direc- tions, with the circular or circumductory ; and in addition a movement of rotation. In the swinging or to and fro movement, the carrying forwards of the humerus constitutes flexion, and the moving it backwards, extension. Flexion is freer than extension ; and when the joint is most bent the scapula, rotating on its axis, follows the head of the humerus, so as to keep the centre of the glenoid fossa applied to the middle of the articular surface of the arm-bone. In extension the articular surface of the scapula does not move after the humerus. During these movements the head of the bone rests in the bottom of the glenoid fossa, turning forwards and backwards around a line represent- ing the axis of the head and neck ; and it cannot be dislodged by either the rapidity or the degree of the motion. The muscles have more influence than the loose capsule in controlling the swingring: motion. Abduction and adduction. AVhen the limb is raised, it is abducted, and when depressed, adducted ; and in both cases the humerus rolls on the scapula which is fixed. During abduction the head of the humerus, descends to the lower and larger part of the glenoid fossa, and projects beyond it against the cap- sule ; whilst the great tuberosity rubs against the arch of the acromion. In this condition a little more movement down of tlie head either by muscles depressing it, or by force elevating the farther end of the bone, will throw it out of place, giving rise to dislocation. In adduction the head of the bone rises into the socket, the limb meets the trunk, and the tense capsule is set at rest. After the reduction of a dislocation the limb is fixed to the side in this position of security against further displacement. In circumduction the humerus passes in succession through the four different states before mentioned, and the limb describes a cone, whose apex is at the shoulder and base at the digits. Rotation. There are two kinds of rotatory movement, viz., in and out ; and in each the motion of the head and shaft of the bone has to be considered. In rotation in, the great tuberosity is turned forwards, and the liead rolls from before back across the glenoid fossa so as to projec^t behind. The shaft is moved forwards round a line lying on its inner side, which reaches from the centre of the head to tlie inner condyle. In rotation out, the osseous movements are reversed ; thus the tuberosity turns back, the head rolls forward so as to project in front, and the shaft is carried back around the line before said. The upper thickened part of the capsule will be tightened in rotation, but the muscles are the chief agents in checking the movements. Dissection. To make the necessary dissection of the ligaments of the LIGAMENTS OF ELBOW 293 Fiff. 90. elbow, the brachialis anticus must be taken away from the front, and the triceps from the back of the joint. The muscles connected with the outer and inner condyles of the humerus, as well as the supinator brevis and the flexor profundus, are to be removed. With a little cleaning the four ligaments — anterior, posterior, and two lateral — will come into view. The interosseous membrane between the bones of the forearm will be prepared by the removal of the muscles on both sui-faces. The Elbow Joint (fig. 90). In this articulation the lower end of the humerus is received into the hollow of the ulna, so as to produce a hinge- like arrangement ; and the upper end of the radius assists to form part of the joint. Where the bones touch the surfaces are covered with cartilage, and their articular ends are kept in place by the following ligaments : — The external lateral ligament is a roundish fas- ciculus, which is attached by one end to the outer condyle of the humerus, and by the other to the orbicular ligament around the head of the radius. A few of the posterior fibres pass backwards to the external margin of the ulna. The internal lateral ligament is triangular in shape. It is pointed at its upper extremity, and is connected to the inner condyle of the humerus. The fibres diverge, and are inserted in this way: — The anterior, which are the strongest, are fixed to the edge of the coronoid process ; the posterior are attached to the side of the olecranon ; whilst a few middle fibres join a transverse ligamentous band over the notch between the olecranon and the coro- noid process. The ulnar nerve is in contact witli the ligament; and vessels enter the joint by an aperture beneath the transverse band. The anterior ligament is thin, and its fibres are separated by intervals in which masses of fat are lodged. By its upper edge the ligament is inserted into the front of the humerus, and by its lower into the front of the coronoid process and the or- bicular ligament. The brachialis anticus muscle covers it. The posterior ligament is much thinner and looser than the anterior, and is covered completely by the triceps muscle. Superiorly it is attached to the humerus above the fossa for the olecranon ; and inferiorly it is inserted into the olecranon. Some few fibres are transverse between the mar- gins of the fossa before mentioned. Dissection. Open the joint by an incision across the front near the humerus, and disarticu- late the bones, in order that the articular surfaces may be seen. The synovial tnemhrane of the joint can be traced from one bone to another along the inner surface of the connecting ligaments. It projects between the radius and the orbicular ligament, and serves for the articu- lation of the head of that bone with the small sigmoid cavity of the ulna. The Lioamen-ts op the El- bow Joint, and thb Shaft of the Radios AND Ulna (Bourgery and Jacob). 1. Capsule of the elbow joint. 2. Oblique lig^ament .3. Interosseous ligament. 4. Aperture for bloodves- sels. 5. Tendon of the biceps. 294 DISSECTION OF THE UPPER LIMB. Articular surfaces. The humerus presents inferiorly two distinct ar- ticular faces for tlie bones of the forearm. The one for the radius, on the outer side, consists of a rounded eminence (capitellum) on the front of the bone, which is covered with cartihige only on the interior aspect. The surface in contact with the ulna is limited internally and externally by a prominence, and hollowed out in the centre (trochlea). On the front of the humerus above the articular surface are two depressions which receive the coronoid process and tlie head of the radius during flexure of the joint ; and on the posterior aspect is a large fossa for the reception of the olecranon in extension of the joint. On the end of the ulna the large sigmoid cavity is narrowed in the cen- tre, but expanded in front and behind (fig. 91). A slightly raised line extends from front to back, and is received into the hollow of the trochlea of the humerus. Across the bottom of the cavity the cartilage is wanting completely, or for a greater or smaller distance. The end of the radius presents a circular depression with a raised mar- gin. In the bent state of the joint the hollow of the radius fits on the outer eminence of the humerus, and the bone is supported during rotation of the limb. Movement. This joint is like a hinge in its movements, and permits only flexion and extension. In flexion the bones of the forearm move forwards, each on its own articular surface, so g,s to leave the back of the humerus uncovered. The extent is checked by the meeting of the bones of the arm and forearm. Owing to the slanting surface of the humerus the hand falls inside the limb when the joint is fully bent. The ligaments are relaxed, with the exception of the following, viz., the posterior, and the hinder part of the internal lateral. In extension the ulna and radius are carried back over the articular sur- face of the humerus until they come into a line with the arm-bone. This movement is checked by the olecranon touching the humerus. The anterior ligament, and the fore part of the internal lateral ligament are made tight, but the hinder fibres of the internal lateral are relaxed. Union of the Radius and Ulna. The radius is connected with the ulna at both ends by means of distinct ligaments and synovial membrane; and the shafts of the bones are united by interosseous ligaments. Upper radio-ulnar articulation. In this joint the head of the radius is received into the small sigmoid cavity of the ulna, and is kept in place by the following ligamentous band : — The annular or orbicular ligameiit (fig. 91, a) is about one-third of an inch wide, and is stronger behind than before; it is ])laced around the prominence of the head of the radius, and is attached to the anterior and posterior edges of the small sigmoid cavity of tlie ulna. Its upper border, the widest, is connected with the ligaments of the elbow joint; but the lower is free, and is applied around the neck of the radius. In the socket formed by this ligament and the cavity of the ulna, the radius moves freely. Tlie synovial membrane is a prolongation of that lining the elbow joint; it projects inferiorly between the neck of the radius and the lower margin of the annular ligament. Ligaments of the shafts of the bones. The aponeurotic stratum con- necting togetiier the bones in nearly their whole length consists of the two following parts : — RADTO-ULXAR JOINTS, 295 Fig. 91. View of the Orbicular Ligament (a) OF THE Radius, which retains THKUPPER KNDOF THE BoNK AGAINST THE Ulna. The interosseous memhrane (.fig. 90, ') is a thin fibrous layer, which is attached to the contiguous margins of the radius and ulna, and forms an incomplete septum between the muscles on the front and back of the fore- arm. Most of its fibres are directed obliquely inwards towards the ulna, though a few on the posterior surface have an opposite direction. Superiorly the membrane is wanting for a considerable space, and through the interval the poste- rior interosseous vessels pass backwards. Some small apertures exist in it for the passage of vessels ; and the largest of these (*) is about two inches from the lower end, through which the anterior interos- seous artery turns to the back of the wrist. The membrane gives attachment to the deep muscles. The round ligame^it (fig. 90, ^) is a slender band above the interosseous mem- brane, whose fibres have a direction oppo- site to tliose of the membrane. By one end it is fixed to the front of the coronoid process, and by the other to the radius be- low the tubercle. The ligament divides the space above the interosseous membrane into two parts. Oftentimes this band is not to be recognized. The lower radio-ulnar articulation cannot be well seen till after the examination of the wrist joint (p. 297). Movement of the radius. Tlie radius moves forwards and backwards around the ulna. The forward motion, directing the palm of the hand towards the ground, is called pronation ; and the backward, by which the palm of tl)e hand is placed upwards, is named supination. In pronation the upper end of the bone rotates within the band of the orbicular ligament without shifting its position to the ulna. The lower end, on the contrary, moves over the ulna from the outer to the inner side, describing half a circle ; and the shaft crosses obliquely that of the ulna. In supination the lower end of tlie radius turns backwards over the ulna ; the shafts come to be placed side by side, the radius being external ; and the upper end rotates from within out in its circular band. In these movements the radius revolves round a line, internal to the shaft, which is prolonged upwards through the neck and head of the bone, and downwards through the centre of a circle of which the small sigmoid cavity of the ulna is a segment (Ward). The upper end of the bone is kept in place by the orbicular ligament ; the lower end by the triangular fibro-cartilage; and the shafts are united by the interosseous ligament, which is tightened in supination, and is re- laxed in pronation. In fracture of either bone the movements cease ; in the one case be- cause the radius cannot be moved except it is entire ; and in the other, because the ulnar support is wanting for the revolving radius. Dissection. To see the ligaments of the wrist-joint, the tendons and the annular ligaments must be removed from both the front and back ; and 296 DISSECTION OF THE UPPER LIMB. Fiff. 92. the fibrous structures and the small vessel^ should be taken from the sur- face of the ligaments. The Wrist Joint (fig. 92). The lower end of the radius, and the first row of the carpal bones, except the os pisiforme, enter into the wrist- joint. Four ligaments maintain in contact the osseous surfaces, viz., an- terior and posterior, and two lateral. The ulna is shut out from this ai'ticu- lation by means of a piece of fibro- cartilage. The external lateral ligament is a short and strong band, which inter- venes between the styloid process of the radius and the outer part of the scaphoid bone. The internal lateral ligament is smaller than the external, but is longer than it. It is attached by one end to the styloid process of the ulna, and by the other to the rough, upper part of the cuneiform bone. Some of the anterior fibres are continued to the pisiform bone. The anterior ligament (fig. 92, ^) takes origin from the radius and the fibro-cartilage, and is inserted into the first row of carpal bones, except the pisiform, at the anterior surface. The posterior ligament (fig. 95, ^) is membranous, like the anterior, and its fibres are directed downwards and inwards. Superiorly it is attached to the radius and the fibro-cartilage ; and inferiorly it is fixed, like the anterior, to the three outer carpal bones of the first row, but on the posterior aspect. Dissection. To see the form of the articulating surfaces, the joint may be opened by a transverse incision through the posterior ligament, near the bones of the carpus. Articular surfaces. The end of the radius, and the fibro-cartilage uniting it with the ulna, form an arch for the reception of the carpal bones (fig. 93) ; and tlie surface of tlie radius is divided by a prominent line into an external triangular, and an internal square impression. The three bones of the first carpal row constitute a convex eminence (fig. 94), which is received into the hollow before mentioned in this way : The scaphoid bone (a) is opposite the external mark of the radius ; the semi- lunar bone {h) touches the square impression, and all or part of the trian- gular fibro-cartilage ; whilst the cuneiform bone (^) is in contact with the capsule (Henle), and sometimes with part of tlie fibro-cartilage. The synovial membrane has the arrangement common to simple joints. This joint communicates occasionally with tlie lower radio-ulnar articula- tion by means of an aperture in the fibro-cartilage se[)arating tlie two. Movement. The wrist is a condyloid articulation, and possesses angular motion in four different directions, with circumduction. Fkont View of the Articulations of the Wrist Joint, and Carpal and Meta- carpal Bones (Bourgery and Jacob). 1. Anterior ligament of the wrist joint. 2. Capsule of the joint o^ the metacarpal bone of the thumb with the os trapezium. 3. Pisiform bone, with its separate joint and ligamentons bands. 4. Transverse bands to the head of the meta- carpal bones. LIGAMENTS OF WRIST JOINT, 297 Fiff. 93. Flexion and extension. In flexion the hand is moved forwards and in- wards, whilst the carpus rolls on the radius from before back, and projects behind, stretching the posterior ligament. In extension the hand is car- ried backwards and outwards, and the row of carpal bones moves in the opposite direction, viz., from behind forwards, so as to cause the anterior ligament to be tightened. The hinder movement is freer than the forward. Abduction and adduction. The row of carpal bones moves transversely inwards in the former, and outwards in the latter state ; and the move- ment is freer towards the ulnar than the radial side. The latter ligaments are put on the stretch, the inner in abduction and the outer in adduction ; and the motion is limited on the outer side by the meeting of the styloid processes of the radius with the scaphoid bone. Circumduction. The hand describes a cone in this movement, whose apex is at the wrist and base at the digits ; and it moves more freely in extension and adduction than in the opposite directions. Lower Radio-ulnar Articulation. In this articulation the con- vexity of the end of the ulna is received into a concavity on the radius ; an arrangement just the opposite to that be- tween the upper ends of the bones. The chief bond of union between the bones is a strong fibro-cartilage ; but a kind of capsule consisting of scattered fibres, sur- rounds loosely the end of the ulna. The triangular fibro-cartilage (fig. 93, c) is placed transversely beneath the end of the ulna, and is thickest at its margins and apex. By its base the cartilage is fixed to the ridge which separates the carpal from the ulnar articulating surface of the radius ; and by its apex to the styloid process of the ulna, and the depression at the root of that point of bone. Its margins are united with the con- tiguous anterior and posterior ligaments of the wrist joint ; and its surfaces enter into different joints, viz., the wrist, and the lower radio-ulnar. It serves to unite the radius and ulna, and to form part of the socket for the carpal bones ally it is perforated by an aperture. The synovial membrane (membrana sacciformis) is very loose, from which circumstance it has received its name, and ascends between the radius and the ulna : it is separated from that of the wrist-joint by the triangular fibro-cartilage. The use of this articulation is referred to with the movements of the radius (p. 295). Union of the Carpal Bones. The several bones of the carpus are united into two rows by dorsal, palmar, and interosseous bands : and the two rows are connected to each other by separate ligaments. Dissection. The articulation of the carpal bones with each other will be prepared by taking away all the tendons from the hand, and cleaning carefully the wiiole of the connecting ligamentous bands. Two distinct ligaments of tlie pisifbim bone to the uncilbrm and fifth metacarpal are to be defined in the palm. The Wkist Joint opened to show the arch formed by the bones OF THE Forearm with the unit- ing FlBKO-CARTILAQE, C. a. Radius. b. Ulna. Occasion- 298 DISSECTION OF THE UPPER LIMB. At the same time the ligamentous bands uniting the metaearpal with the carpal bones and with one another should be dissected. Bones of the first roxo (fig. 94). The os semilunare is united to the lateral bones, viz., scaphoid and cuneiform by a dorsal (fig. 94, o?), and a palmar transverse band ; as well as, it is said, by an interosseous ligament at the upper part of the continuous surfaces.^ The pisiform bone is articulated to the front of the cuneiform by a dis- tinct capsule and a synovial membi'ane (fig. 92, ^). It has further two special firm ligaments : one of these is attached to the process of the os unciforme, and the other to the base of the fifth metacarpal bone. The bones of the second row are connected together in the same way as those of the first, viz., by a dorsal and a palmar band of fibres from one bone to another. Between the contiguous rough surfaces of the several ossicles are interosseous ligaments, one in each interval. Movement. Only a small degree of gliding motion is permitted between the different carpal bones, in consequence of the fiattened articular sur- faces, and the interosseous ligaments uniting one to anotlier ; and this is less in the second than in the first row. One row with another (transverse carpal joint, fig. 94). The two rows of carpal bones are connected by an anterior and posterior, and two lateral ligaments. The anterior ligament (p) consists of strong irregular fibres, and inter- venes between the two rows (except the pisiform) on the palmar aspect. The posterior ligament, which is longer and looser, and the greater num- ber of whose fibres are transverse, has a corresponding attachment on the dorsal aspect of the same bones. Fig. 94. a. Scaphoid bone. b. Semilunar. c. Cuneiform. d. Dorsal transverse bands between those bones. e. Trapezium bone. /. Trapezoid. g. Os magnum. h. Unciform. i. Dorsal transverse bands joining the bones. k. External lateral ligament of the intercarpal joint. I. Internal lateral. p Anterior ligaments. Aeticulations of one Carpal Bone with another, and of the two rows with each OTHER. Thk Joint between the two rows is opened behind. Of the lateral ligaments the external {k) is the best marked, and ex- tends between the os trapezium and the scaphoid bone ; the internal liga- ment (/) reaches between the cuneiform and unciform bones. Dissection. After the division of the lateral and posterior ligaments, • Interosseous ligaments in this row, distinct from the other bands, can scarcely be said to exist. CARPO-METACARPAL JOINTS. 299 the one row of bones may be separated far enough from the other, to allow a siglit of the articular surfaces. Articular surfaces. The first row of carpal bones (except pisiform) forms internally an arch with the scaphoid {a), semilunar {d), and cunei- form bone (c), whose hollow is turned towards the second ; and externally a prominence with tlie scaphoid {a) which is received into a concavity in the other row. In the second row the os magnum (g) and os unciforme (A) present a condyloid projection, which is received into the arch before mentioned; but the two outer bones (trapezium and trapezoid, e and/) are much below the level of the otliers, and form a slight hollow for the reception of the outer part of the scaphoid bone. One synovial membrane serves for the articulation of all the carpal bones, except the pisiform with the cuneiform. Lining the joint between the two rows of the carpus, the membrane sends upwards and downwards prolongations between the individual bones. The offsets upwards are two, and they sometimes join the synovial membrane of the wrist joint ; but the offsets in the opposite direction are three, and may be continued to all, or only to some of the articulations between the four inner metacarpal with their carpal bones. Movements. The transverse carpal joint is partly condyloid, but only forward and backward motion is permitted. All lateral and circumduc- tory movement is arrested, if the rows are closely applied together, by the scaphoid striking against the os magnum on the one side, and the cunei- form against the unciform on the other. Flexion. As the hand is bent forwards the lower row of carpal bones moves backwards, and renders pro- Fig. 95. minent the posterior ligament. This motion is also brouglit into play in full bending of the wrist. Extension. The backward move- ment is freer than flexion. As the lower carpal row moves towards the palm, its progress is checked by the anterior ligament of the joint, and by the strong flexor tendons. Union of the Metacarpal Bones. The metacarpal bones of the four fingers are connected at their bases by the following liga- ment : A superficial dorsal (fig. 95) and palmar fasciculus of fibres passes transversely from one bone to the next ; and the bands in the palm are the strongest (fig. 92). Besides, there is a short interosseous ligament between the contiguous rough sur- faces of the bones. Lateral union. Where the meta- carpal bones touch they are covered by cartilage ; and the articular sur- faces are furnished with prolongations of the synovial membrane serving for their articulation with tlie carpus. At the anterior extremities the same four metacarpal bones are con- PosTEKioR Ligaments of the Wrist, and Carpal and Metacarpal Bones (Boar- geiy and Jacob). 1. Posterior raJio-carpaL 2. Carpo-inetacarpal joint of tho thumb. .3, 3. Transverso bands between the bases of the metacarpal bones. 300 DISSECTION OF THE UPPER LIMB. nected by the deep transverse ligament which was seen in the dissection of the hand (p. 280). Union of the Metacarpal and Carpal Bones. The metacarpal bones of tlie finorers are articulated with the carpal bones after one phin ; but the bone of the thumb has a separate joint. Tlie metacarpal hone of the thiunh articulates with the os trapezium ; and the ends of the bones are incased in a separate capsular ligament (fig. 92, ^). The joint is furnished with a synovial membrane which is simple in its arrangement. The thumb-joint possesses angular movement in opposite directions, with opposition and circumduction, thus : — Flexion and extension. When the joint is flexed the metacarpal bone is brought into the })alm of the hand, without the ball of the thumb being turned to the tips of the fingers. Extension of the joint is very free, and by it the metacarpal bone is removed from the palm towards the outer border of the forearm. Abduction and adduction. By these movements the metacarpal bone is placed in contact with, or removed from the fore finger. Opposition. In this movement the ball of the thumb is turned towards the tip of each finger by a half circumductory motion of the metacarpal bone ; and in picking up a pin the joints of the thumb, and the two last joints of the fingers will be bent. The metacarpal bones of the fingers receive longitudinal bands from the carpal bones on both aspects, thus : — The dorsal ligaments (fig. 95) are two to each, except to the bone of the little finger. The bands of the metacarpal bone of the fore finger come from the os trapezium and os trapezoides; those of the third metacarpal are attached to the os magnum and os trapezoides; the bone of the ring finger receives its bands from the os magnum and os unciforme ; and to the fifth metacarpal bone there is but one ligament from the unciform. The palmar ligaments (fig. 92) are weaker and less constant than the dorsal. There is one to each metacarpal bone, except that of the little finger. These ligaments may be oblique in direction ; and a band may be divided between two, as in the case of the ligament attached to the os tra- pezium and the second and third metacarpals. Sometimes one or more may be wanting. On the ulnar side of the metacarpal bone of the middle digit is a longi- tudinal lateral band, which is attached above to the os magnum and unci- forme, and below to the rough ulnar side of the base of the above mentioned bone. Sometimes this band isolates the articulation of the last two meta- carpals with the unciform bone from the remaining carpo- metacarpal joint; but more frequently it is divided into two parts, and does not form a com- plete partition. This band may be seen by opening behind the articulation between the unciform and the last two metacarpal bones ; and by cutting through the transverse ligaments joining the third and fourth metacarpals so as to allow their separation. Movement. Scarcely any appreciable antero-posterior movement exists in the articulations of the bases of the metacarpal bones of the fore and middle fingers; but in the ring and little fingers the motion is greater, with slight abduction and adduction. Dissection. The articulating surfaces of the bones in the carpo-meta- METACARPAL BONE AND FIRST PHALANX 301 carpal articulation may be seen by cutting through the rest of the liga- ments on the posterior aspect of the hand. ArticiUar surfaces. Tiie metacarpal bone of the fore finger presents a hollowed articular surface, which receives the prominence of the os tra- pezoides, and articulates laterally with the os trapezium and os magnum. The middle finger metacarpal articulates with the os magnum. The metacarpal bone of the ring finger touches the unciform bone and the os magnum. And the little finger bone is opposed to the os unciforme. Synovial membranes. Usually two synovial membranes are interposed between the carpal and metacarpal bones, viz., a separate one for the bone of tlie thumb, and offsets of the common carpal synovial sac (p. 299) for the others. Sometimes there is a distinct synovial sac for tiie articulation of the OS unciforme with the two inner metacarpals. Interosseous ligaments. The interosseous ligaments between the bases of the metacarpal bones may be demonstrated by detaching one bone from another. There are also strong fibrous pieces between all the carpal bones in the second row ; and slight ones are described as present on each side of the OS semilunare in the first row. Dissection. For the examination of the joint between the head of the metacarpal bone and the first phalanx of the finger, it will be requisite to clear away the tendons and the tendinous expansion around it. A lateral ligament on each side, and an anterior thick band are to be defined. One of the joints may be opened to see the articular surfaces. The same dissection may be made for the articulations between the pha- langes of the finger. Union of Metacarpal Bone and First Phalanx (fig. 96). In this joint the convex head of the metacarpal bone is received into the glenoid fossa of the phalanx, and the two are retained in contact by the extensor and flexor tendons, and by the following liga- ments : — The lateral ligament (a) is the same on both sides of the joint. P^ach is triangular in form : it is attached by its upper part to the tubercle on the side of the head of the metacarpal bone, and below it is inserted into the side of the phalanx and the anterior ligament. The anterior ligament {b) is a longitu- dinal band, which is fixed firmly to the phalanx, but loosely to the metacarpal bone. It is fibro-cartilaginous in texture, and is grooved for the flexor tendon : to its sides the lateral ligaments are attached. Covering the upper part of the joint is the extensor tendon ; this takes the place of a dorsal ligament, and sends down an expansion on each side which serves as a capsule to the articulation. The synovial membrane of the joint is a simple sac. In the articulation of the thumb two sesamoid bones are connected with the anterior ligament, and receive most of the fibres of the lateral liga- ments. Movements. Motion in four opposite directions, and circumduction, exist in these condyloid joints. Fig. 96. 302 DISSECTION OF THE UPPER LIMB. Extension and flexion. The phalanx moves backwards in extension, so as to give an angle with the metacarpal bone. The anterior ligament and the flexor tendons are stretched, and control the movement. In flexion the phalanx glides forwards under the head of the metacarpal bone, and leaves this exposed to form the knuckle when tlie finger is shut. The lateral ligaments and the extensor tendon are put on the stretch as the joint is bent. Abduction and adduction are the lateral movements of the finger from or towards the middle line of the hand. The lateral ligament of the side of the joint which is convex will be tightened, and the other will be relaxed. The circumductory motion is less impeded in the thumb, and in the fore and little fingers tlian in the others ; and in tlie thumb it allows the turn- ing of the last phalanx towards the other digits in the movement of oppo- sition. Union of the Phalanges. The ligaments of the first joint are simi- lar to those in the metacarpo-phalangeal articulation, viz., two lateral and an anterior. The lateral ligaments are triangular in form. Each is connected by its apex to the side of the phalanx near the anterior part ; and by its base to the contiguous phalanx and the anterior ligament. The anterior ligament has the same mode of attachment between the extremities of the bones as in the metacarpo-phalangeal joint, but it is not so strong ; and the extensor tendon takes the place of a posterior band as in that articulation. There is a simple synovial membrane present in the joint. The joint of the second with the last phalanx is like the preceding in the number and disposition of its ligaments ; but all the articular bands are much less strongly marked. Articular Surfaces. The anterior end of each phalanx is marked by a pulley-like surface. The posterior end presents a transversely hollowed fossa, and is provided with a crest which fits into the central depression of the opposed articular surface. Movements. The two interphalangeal joints can be bent and straight- ened like a hinge. Flexion and extension. In flexion, the farther phalanx moves under the nearer in each joint, and the motion is checked by the lateral ligaments and the extensor tendon : in the joint between the middle and the meta- carpal phalanx this movement is most extensive. In extension the farther phalanx comes into a straight line with the nearer one and the motion is stopped by tlie anterior ligament and the flexor tendons. CHIEF ARTERIES OF THE UPPER LIMB 303 TABLE OF THE CHIEF ARTERIES OF THE UPPER LIMB. f Superior thoracic The subclavian is coatiuued in the arm by ... . f 1. Axillary artery. 2. brachial artery. 3. radial artery. 4. ulnar artery. acromial thoracic . . long thoracic alar thoracic subscapular . . . . external mammary anterior circumflex ^ posterior circumflex. f To coraco-brachialis superior profunda . nutritious inferior profunda . . anastomotic l^ muscular. f Recurrent muscular superficial volar posterior carpal anterior carpal metacarpal dorsal of the thumb of the index finger princeps pollicis raJialis indicis Muscular inferior acromial humeral thoracic. Dorsal artery muscular ( Muscular to tt < and anconeus ( anastomotic. Muscular to ti'iceps anastomotic. Infrasca- pular r Recurrent arch J perforating t interosseous communicatinj Anterior recurrent posterior recurrent interosseous . . muscular dorsal of the hand, or metacarpal . . . Anterior . posterior. Nutritious muscular. Recnrrent muscular. Dorsal carpal metacarpal or inter- osseous. anterior carpal i^ superficial arch f Communicating • four digital urauches I cutaneous t muscular. 304 SPINAL NERVES OF THE UPPER LIMB, TABLE OF THE SPINAL NERVES OF THE UPPER LIMB, r Anterior thoracic . \ ^^7;;^"^*^ Beachiai. PLEXUSgives off below the clavicle . . subscapular . circumflex . Superior iuferior long. Articular cutaneous to teres minor to deltoid. nerve of Wrlsberg. C Small cutaneous internal cutaneous . < anterior of forearm ( posterior of forearm. musculo-cutaneous median ulnar. To coraco-brachialis biceps and brachialis auticus cutaneous external of forearm articular to carpus. To pronator teres to muscles of forearm, except flexor ulnarus and part of profundus anterior interosseous cutaneous palmar to muentery. An upper group lies by the side of the artery, and contains the largest glands ; and a lower group, near the intestine, is lodged in the intervascular spaces. The chylilerous vessels of the small intestine, and the absorbents of the i)art of the large intestine supplied by the superior mesenteric artery, pass through the mesenteric glands in their course to the thoracic duct. Along the side of the ascending and the transverse colon are a few other small lymphatic glands meso-colic, which receive some absorbents of the large intestine. Dissection (fig. 144). By drawing the small intestine over to the right side, the dissector will observe the inferior mesenteric artery on the front of the aorta a little above the bifurcation. The peritoneum should be re- moved from it, and the branches should be traced outwards to the remain- ing half of the large intestine : a part of the artery enters the pelvis, but this will be dissected afterwards. On the artery and its branches the in- ferior mesenteric plexus of nerves ramifies. The mesenteric vein is to be followed upwards, away from the trunk of the artery, to its junction with the splenic, or with the superior mesenteric vein. On the aorta the dissector will meet with a plexus of nerves, which is to be left uninjured. The inferior mesenteric artery (fig. 144, 6) supplies branches to the part of the large intestine beyond the transverse colon ; and communi- 442 DISSECTION OF THE ABDOMEN eating with the superior mesenteric, assists to maintain the chain of anas- tomosis along the intestinal tube. This vessel is of smaller size than the superior mesenteric, and arises from the aorta, from one to two inches above the bifurcation. At first the vessel descends on the aorta, and crosses the left common iliac artery, as it courses to the pelvis to end in branches for the rectum (superior haemorrhoidal). The following branches are furnished by it to the de- scending colon and the sigmoid flexure. Fig. 144. The Lower Mesenteric Artery, and the Aorta, seeu by turning aside tlie upper iuesente:ic artery and the small intestine. (Tiedemann). a. Aorta. 6. Inferior mesenteric artery. c. Left colic. d. Sigmoid, and e, Superior hsemorrhoidal branches. /. Upper mesenteric. g. Renal. h. Spermatic of the left side. a. The left colic artery {c) ascends in front of the left kidney, and divides into an ascending and a descending branch for the supply of the descending colon : by the ascending offset it anastomoses with the middle colic branch of the superior mesenteric. h. The sigmoid artery (d) is distributed to the sigmoid flexure, and divides into offsets which anastomose above with f^a preceding colic, and below with the haemorrhoidal brancii. Here, as in the rest of tiie intestinal tube, arches are formed by the arteries beiore they reach the intestine. VISCERAL PLEXUSES OF SYMPATHETIC. 443 c. The superior hcemorrhoidal artery (e) enters between the layers of the meso-rectum, and is distributed to the lower part of the great intes- tine : it will be described in the dissection of the pelvis. The inferior mesenteric vein (fig. 146, c?) begins in the part of the great intestine to which its companion artery is distributed, and ascends along the psoas muscle to open into the splenic vein beneath the pancreas. Oc- casionally it joins the superior mesenteric vein. Both mesenteric veins are without valves, and may be injected from the trunk to the branches, like an artery. Lymphatic glands are ranged along the descending colon and the sig- moid flexure. The absorbents of the intestine, after passing through those glands, enter the left lumbar lymphatic glands. Sympathetic Nerve. The following plexuses of the sympathetic on the vessels, viz., superior mesenteric, aortic, spermatic, and inferior mesenteric, are derived from the solar plexus beneath the stomach. The remaining portion of the sympathetic nerve in the abdomen will be subse- quently referred to. Dissection. On the two mesenteric arteries the dissector will have made out, already, the plexuses of nerves distributed to the intestinal tube beyond the duodenum. He has now to trace on the aorta the connecting nerves between the mesenteric plexuses, by taking the peritoneum from the aorta between the mesenteric vessels. From the upper part of the aortic plexus an offset is to be followed along the spermatic artery ; this may be done, on the left side, where the vessel is partly laid bare. By removing the peritoneum from the front of the sacrum, and follow- ing downwards, over the iliac arteries, the nerves from the aortic plexus and the lumbar ganglia, tlie dissector will arrive at the hypogastric plexus of the pelvis, opposite the top of the sacrum. The superior ynesenteric plexus is a large offset, and is distributed to the same extent of the intestinal tube as the mesenteric artery. The nerves surround closely the artery with a sheath, but near tjie intestine some of them leave the vessels, and divide and communicate before enter- ing the gut. Branches. The secondary plexuses are the same as the off- sets of the artery, viz., intestinal nerves to the small intestine; and an ileo-colic, a right colic, and a middle colic plexus to the large intestine. The aortic plexus is the network of nerves covering the aorta below the superior mesenteric artery ; it is stronger on the sides than the front of the aorta, in consequence of its receiving accessory branches from the lumbar ganglia, especially the left. At the upper part the plexus derives an offset, on each side of the aorta, from the solar and renal plexuses. It ends interiorly, on each side, in branches which cross the common iliac artery, and enter the hypogastric plexus of the pelvis. From it offsets are furnished to the spermatic and inferior mesenteric arteries. The spermatic plexus^ formed by roots from both the aortic and the renal plexus, runs on the spermatic artery to the testicle ; in the cord it joins other filaments on the vas deferens. In the female, the nerves on the ovarian (spermatic) artery are furnished to the ovary and the uterus. The inferior mesenteric plexus supplies the part of the intestinal tube to which the artery is distributed. This plexus is furnished from the left part of the aortic plexus ; and the nerves composing it are whiter and larger than in either of the preceding plexuses of the sympathetic. Near 444 DISSECTION OF THE ABDOMEN. the intestine (sigmoid flexure) the branching of the nerves and the union of contiguous twigs are well marked. Branches. Its secondary plexuses are named from the arteries they accompany, viz., left colic, sigmoid, and superior hasmorrhoidal : they ramify on the vessels, and have a like distribution. The hypogastric plexus, or the large prevertebral centre for the supply of sympathetic nerves to the viscera of the pelvis, is situate in front of the upper part of the sacrum. It is developed more on the sides than in the centre ; and the nerves, which are large and flat, have a plexiform arrangement, but without any intermixed ganglionic masses. By its upper part it receives the nerves on the aorta, and is joined by some filaments from one or two of the upper sacral ganglia. Inferiorly the plexus ends in two parts, right and left, the last being the largest : each is continued forwards by the side of the internal iliac artery to the pelvic plexus of the same side, and to the viscera. CONNECTIONS OF AORTA AND VENA CAVA. Before the viscera are removed from the body, the connections of the abdominal aorta and vena cava may be learnt. , Dissection. To see the aorta above the origin of the superior mesen- teric artery, it will be necessary to detach the great omentum from the stomach, without injuring the gastro-epiploic artery along the great curve ; and after raising the stomach and the spleen, to remove the peritoneum from the surface of the pancreas. A short arterial trunk (coeliac axis) above the pancreas is not to be cleaned now, otherwise the nerves about it would be destroyed. The vena cava on the right side of the aorta may be followed as far as the posterior border of the liver, where it disappears. The connections of its upper part can be better observed after the dissection of the ves- sels of the liver. The aortcii enters the abdomen between the pillars of the diaphragm, and divides into iliac arteries opposite the left side of the iburth lumbar vertebra. At the beginning the vessel occupies the middle line of the spine, but it gradually inclines to the left as it descends. In the abdomen the aorta lies behind all the viscera ; but it is crossed more immediately by the pancreas and duodenum, which it touches with- out the intervention of peritoneum. Its connections are the following : at first it is covered by the solar plexus, and by the pancreas and the splenic vein ; still lower (beyond the superior mesenteric artery) by the left renal vein and the duodenum ; and thence to its termination by the peritoneum and the aortic plexus. The vessel lies on the lumbar vertebras, with the pillars of the diaphragm embracing it at the beginning. To its right side is the vena cava. Its relation to other deep parts is mentioned in p. 489. The vena cava inferior commences on the right side of the fifth lumbar vertebra by the union of the common iliac veins, and reaches thence to the heart. The venous trunk is placed on the right side of the vertebral column. It lies close to the aorta, and is concealed by the same viscera as high as the crus of the diaphragm ; but above that spot it is inclined away from the artery, and ascending on the right of the crus of the diaphragm, is imbedded in the posterior part of the liver for an inch or more. Lastly, DUODENUM AND PANCREAS. 445 it leaves the abdomen by an aperture in the tendinous centre of the dia- phragm, on the right of, and higher th'in the aortic opening. Its connections with vessels are not the same as those of the aorta. Beneath it are the right lumbar, renal, capsular, and diaphragmatic arteries ; and crossing over it below the kidney is the spermatic. Super- ficial to it beneath the pancreas is tlie beginning of the vena portae. Off- sets of the solar plexus of nerves descend on it, as on the aorta. CONNECTIONS OF THE DUODENUM AND PANCREAS. Dissection. To see satisfactorily the duodenum and the pancreas the intestinal tube, beyond the duodenum, is to be removed in the following way : — a double ligature is to be placed on the upper part of the jejunum, another on the lower end of the sigmoid flexure of the colon, and the gut is to be cut through at the points at which it is tied. The detached piece of the intestinal tube is to he taken away by cutting through the vessels, and the peritoneum connecting it to the wall of the abdomen. After it has been separated, it is to be set aside for future study whilst the body is turned. The student should moderately inflate the stomach and duodenum from the cut extremity of the latter, and remove the loose peritoneum and the fat ; whilst cleaning them, he should lay bare the larger vessels and nerves. On turning upwards the stomach the pancreas may be traced from the spleen on the one hand to the duodenum on the other (fig. 145). By pulling forwards the duodenum, the common bile duct may be found, posteriorly, between the intestine and the head of the pancreas ; and some of the pancreas should be removed, to show its duct entering the duodenum. Duodenum (fig. 145, d). The first part of the small intestine, or the duodenum, begins at the pyloric end of the stomach, and crossing the spinal column, ends on the left side of the second lumbar vertebra. It makes a curve around the head of the pancreas, and occupies the right hypochondriac, right lumbar, and umbilical regions of the abdomen. From its winding course around the pancreas it is divided into three parts — superior transverse, vertical, and inferior transverse. The superior transverse part is free and movable, like the stomach ; it measures about two inches in length, and is directed from the pylorus to the neck of the gall bladder, ascending slightly between one point and the other. In front it is overlapped by the liver, as well as by the gall blad- der when this is distended ; and behind it are the bile duct and the vena portae. The vertical part is fixed almost immovably by the peritoneum and the pancreas. It is nearly three inches in length, and descends from the gall bladder as far as the third lumbar vertebra. Superficial to this [)art is the right bend of the colon ; and beneath it are the kidney and its vessels. On its inner side is the head of the pancreas, with the common bile-duct. The ducts of the liver and pancreas pour their contents into this portion of the duodenum. The inferior transverse part is the longest of the three, and is continued across the spinal column to end in the jejunal portion of the small intes- tine. As it crosses the spine, it ascends trom the third to the level of the 446 DISSECTION OF THE ABDOMEN. second lumbar vertebra, and lies between the layers of the transverse meso-colon. It has the following connections with the ]).arts around: — In front of it are the superior mesenteric vessels witii their plexus of nerves. Beneath it lie the vena cava and the aorta, with the pillars of the diaphragm ; and the left renal vein is sometimes between it and the aorta. Above it is the pancreas. Pancreas (fig. 145, ^■). The pancreas is situate behind the stomach, and has numerous and complicated connections. Of an elcngated form, it extends across the spine from the spleen to the duodenum, and occupies the left hypochondriac, the umbilical, and the right lumbar region of the abdomen. The gland is covered anteriorly by the ascending layer of the transverse meso-colon. It is in contact posteriorly with tlie aorta, the vena cava, and the pillars of the diaphragm ; and it conceals likewise the splenic vein and the commencement of the vena portce. Projecting above the upper border, near the centre, is the arterial trunk of the coelic axis : to the left of that vessel, along the same border, is placed the splenic artery ; whilst to tlie right of it lie the hepatic artery and the first part of the duodenum. At the lower border the superior mesenteric vessels emerge opposite the coelic axis ; to the right of that spot lies the third part of the duodenum, and to the left the inferior mesen- teric ascending to join the splenic vein. The left end or the tail of the pancreas touches the spleen, and is phiced over the left kidney. The right extremity or the liead is received into the concavity of the duodenum, the two being partly separated by the common bile duct and the pancreatico-duodenal arteries. Tliis part pro- jects above and below the body of the gland, like the head of a hammer beyond the handle ; and the lower projecting piece is directed to the left along the duodenum beneath the superior mesenteric vessels. CcELIC AXIS AND VENA PORT^. A short branch of the aorta — the coeliac axis, furnishes arteries to the stomach and duodenum, the liver, pancreas, and spleen ; it subdivides into three chief branches — coronary, hepatic, and splenic. The veins corresponding with the arteries (except the hepatic) are col- lected into one trunk — the vena portae. Dissection. The vessels have been in part laid bare by the previous dissection, and in tracing them out fully the student sliould spare the plexuses of nerves around each. Supposing the liver well raised, he may first follow to the left side the small coronary artery, and show its branches to the oesophagus and the stomach. Next the hepatic artery, with the vena porta? and the bile duct, may be traced to the liver and the gall bhi(hler ; and a considerable brancli of it should be pursued beneath the pylorus to the stomach, duodenum, and pancreas. Lastly, the splenic artery, which lies along the upper border of the pancreas, is to be cleaned ; and its branches to the pancreas, stomach, and spleen should be defined ; this is a difficult task without the aid of some one to liold aside the stomach and spleen. The veins will iiave been dissected for the most part with the arteries ; but the origin of the vena porta3 is to be made out beneath tlie pancreas, and in front of the vena cava. The CcELiAC AXIS (fig. 145, c) is the first visceral branch of the ab- CCELIAC ARTERY AND BRANCHES. 447 dominal aorta, and arises between the pillars of the diaphragm. It is a short thick trunk, about half an inch long, which projects above the upper border of the pancreas, and is surrounded by the solar plexus of the sym- pathetic. Its branches — coronary, hepatic, and splenic — radiate from the trunk (whence the name axis) to their distribution to the viscera in the upper part of the abdomen. a. The coronary artery (c?) is the smallest of the three, and passes be- tween the layers of the little omentum to the left end of the stomach. At that spot it furnishes some oesophageal branches, and turns from left to right, along the upper border of the stomach, to anastomose with a branch (pyloric) (o) from the hepatic artery. Its offsets to the ccsophagus and the stomach are thus distributed : — (Esophageal branches ascend on the gullet through the opening in the diaphragm, supplying that tube; and they anastomose on it with branches of the thoracic aorta. Gastric branches are given to both sides of the stomach, and those. on the left end communicate with twigs (vasa brevia) of the splenic artery. b. The splenic artery {e) is the largest branch of the coiliac axis in the adult. It is a tortuous vessel, and runs almost horizontally to the spleen, along the upper border of the pancreas. Near the spleen it divides into terminal branches, about seven in number (from four to ten), which enter that viscus by the surface towards the stomach. It is accompanied by the splenic vein, which is below it; and it distributes branches to the pan- creas and the stomach. Pancreatic branches. Numerous small branches are supplied to the gland; and one of these, art. pancreatica magna^ arises near the left end, and runs to the right in the substance of the viscus with the duct. Branches for the stomach arise from the divisions of the artery near the spleen. Some of these, i-asa brevia^ turn upwards to the left end of the stomach, beneath the gastro-splenic omentum, and ramify in the coats of tiiat organ. Another longer branch, art. gastro'epiplo'ica sinistra (/) turns to the righ.t between the layers of the great omentum along the great curvature of the stomach, and inosculates with the riglit gastro-epiploic branch of the hepatic artery. This artery distributes twigs to both surfaces of the stomach, and between the pieces of peritoneum forming the great omentum. c. The hepatic artery (g) is intermediate in size between the other two, and is encircled by the largest plexus of nerves. In its course to the liver the vessel is bent first to the right towards the small end of the stomach, where it supplies its principal branches (superior pyloric and gastro-epiploic). It ascends then between the layers of the little omen- tum, on th(; left side of the bile duct and vena portne, and divides near the transverse fissure of the liver into two — the right and left hepatic. Branches are distributed not only to the liver, but freely .to the stomach, the duodenum, and the pancreas, as below: — The superior pyloric branch (o) descends to the upper border of the stomach, and running from right to left anastomoses with the coronary artery; it distributes small arterial twigs on both surfaces of the stomach. The right gastro-epiploic branch {hy (art. gast. epiploica dextra) de- ' This artery is named commonly fjastro-duodenal as far as to the spot where it gives off the branch to the duodenum and pancreas. 448 DISSECTION OF THE ABDOMEN. sceiids beneath the duodenum near the pylorus, and turning to the left along the great curvature of the stomach, inosculates witii the left gastro-epiploic of the splenic artery. To the surfaces of the stomach some offsets are given; and others descend between the layers of the omentum. It furnishes the following named branches to the stomach, and the pan- creas and duodenum : — Small inferior pyloric branches end in the small extremity of the stomach. Fig. 145. View OF the C(emac Axis, axd of the Viscera to which ITS Branches are Supplied (Tiedmann). A. Liver. B. Gall-bladder, c. Stomach. D. Duodenum, E. Pancreas. F. Spleen. Vessels : a. Aorta. h. Upper mesenteric. c. Cooliac axis. d. Coronary. e. Splenic. /. Left pastro-epiploic. g. Hepatic. h. Right gastro-epiploic. t'. Superior, and fr, inferior pan- creatico-duodenal. I. Diaphragmatic arteries. n. Cystic, o. Superior pyloric. The pancreatico-duodenal branch (?') (superior) arises opposite the duo- denum, and runs between the intestine and the pancreas ; it anastomoses below with the pancreatico-duodendal branch (inferior) of tlie superior mesenteric (fig. 146, h). Both the duodenum and the pancreas receive offsets from this vessel. On the posterior aspect of the same viscera is anotiier small offset of the pancreatico-duodenal with a similar position and distribution. The hepatic branches (right and left) sink into the liver at the trans- verse fissure, and ramify in its substance : — The right branch is divided when about to enter the transverse fissure, and supplies the following small artery to the gall bladder. The cystic artery {n) bifurcates on reaching the neck of the gall bladder, and its two twigs ramify on the opposite surfaces. The left branch is smaller than the other, and enters the liver at the left end of the transverse fissure : a branch to the Spigelian lobe of the liver arises from this piece of the artery. Portal Veins. The veins of the intestinal tube, and of the spleen and pancreas, pour their blood into the vena portal. The two mesenteric veins and their branches have been referred to (p. 441); and the two following, with the trunk of the portal vein, remain to be noticed. The superior coronary vein (fig. 146,/) lies along the upper border of the stomach. It begins in the (Esophagus and the left part of the stomach, and joins the vena portae at the pylorus. The splenic vein (fig. 146) is large in size, and is formed by the union of branches from the spleen. It takes much the same course as, but below VENA PORT^ AND BRANCHES, 449 the artery, and runs beneath the pancreas to the front of the vena cava, where it joins the superior mesenteric vein (b) to form the vena portse. Between its origin and termination it receives branches corresponding with the following arteries : — vasa brevia (g), left gastro-epiploic (e), and pancreatic. The inferior mesenteric vein (c?) opens into it about its middle. The vena portce (fig. 146, a) is formed by the union of the splenic and superior mesenteric veins. Its origin is placed in front of the vena cava, but beneath the pancreas, and two inches from the right end. The vessel is about four inches long, and is directed upwards in the small omentum, behind the bile duct and the hepatic artery, to the transverse fissure of the liver, where it divides into a right and a left branch. Fig. 146. a. Trunk of the vena portae. b. Upper mesenteric. c. Right gastro-epiploic. d. Inferior mesenteric. e. Left gastro-epiploic. /. Coronary of the stomach. g. Vasa brevia. Veka Port^ and the Veins Joininq it (Ilenle: Anataraie des Menschen). In its course it is joined by the coronary vein (/), and by the cystic vein near the liver. The right branch enters the transverse fissure to ramify in the right lobe of the liver. The left branch is distributed to the left part of the liver, and gives a small branch to the Spigelian lobe. 29 450 DISSECTION OF THE ABDOMEN. This vein commences by roots in the viscera above mentioned, like any other vein, but it is deficient in valves ; and it ramifies through the struc- ture of the liver in the same manner as an artery. Its radicles communi- cate with the systemic veins on some parts of the intestinal tube, but more particularly on the rectum. Bile Ducts. Two hepatic ducts issue at the transverse fissure of the liver (fig. 158), one from each lobe, and unite to form the following : — The common hepatic duct is an inch and a half long, and receives at its termination the duct of the gall bladder, the union of the two giving origin to the common bile duct. The common bile duct (ductus communis choledochus) is about three inches long. It descends almost vertically beneath the upper transverse portion of the duodenum ; then passing between the pancreas and the vertical piece of the duodenum, it opens into this portion of the intestine at the inner side, and above the middle. Whilst in the small omentum the duct lies to the right of the hepatic artery, and somewhat before the portal vein. Before piercing the coats of the intestine it is joined commonly by the pancreatic duct, but the two may enter the duodenum separately. SYMPATHETIC AND VAGUS NERVES. Sympathetic Nerve. In the abdomen, as in the thorax, the sympa- thetic nerve consists of a gangliated cord on each side of the vertebral column, and of prevertebral centres or plexuses, which furnish branches to the viscera. Two prevertebral plexuses exist in the abdomen. One of these, the epigastric, is placed behind the stomach, and supplies nerves to all the viscera above the cavity of the pelvis. The other, the hypogastric plexus, is situate in the pelvis, and distributes nerves to the pelvic viscera. The knotted or gan?liated cord will be met with in a subsequent stage of the dissection ; and only the great solar plexus with its offsets is to be now examined. Dissection. To denude the epigastric plexus, the following dissection is to be made : After the air has been let out of the stomach and duode- num, the portal vein, the common bile duct, and the gastro-epiploic vesr sels are to be cut through near the pylorus; and the stomach, duodenum, and pancreas are to be drawn over to the left side. On raising the liver the vena cava appears ; the vein is to be cut across above the junction of the renal vein with it, and the lower end is to be drawn down with hooks. Beneath the vein tlie dissector will find the large reddish semi-lunar ganglion ; and mixed up with the nerves of the plexus are numerous lymphatic glands, and a dense tissue, which require to be removed with care. From its inner part he can trace the numerous nerves and ganglia around the cojliac and superior mesenteric arteries, and the secondary plexuses on the branches of those arteries. From the outer part of the ganglion offsets are to be followed to the kidney, the suprarenal body, and the diaphragmatic arteries : at its upper part the junction with the large splanchnic nerve may be seen ; and deeper than the last, one or two smaller splanchnic nerves may be observed in a fissure of the diaphragm, which throw themselves into the coeliac and renal plexuses. The student should then trace the ending of the pneumogastric nerves on the stomach. The left nerve will be found at the upper border in front EPIGASTRIC OR SOLAR PLEXUS. 451 near the oesophagus ; and the right nerve will be seen at a corresponding point on the opposite aspect. Branches from the right nerve are to be followed to the plexus of the sympathetic by the side of the cfcliac axis, and from the left, to the hepatic plexus. The EPIGASTRIC or solar plexus is a large network of nerves and ganglia, which lies in front of the aorta and the pillars of the diaj)hragm : it fills the space between the suprarenal capsules of opposite sides, and extends downwards to the pancreas, surrounding the cceliac axis and the superior mesenteric artery. The plexus is connected on each side with the large and small splanchnic nerves ; and it is joined also by an offset of the right pneumo-gastric nerve. Large branches are furnished to the different viscera along the vessels. The semilunar ganglia^ one on each side, are the largest in the body, and each is joined at the upper end by the great splanchnic nerve. Each is situate at the outer part of the plexus, close to the suprarenal body, and on the pillar of the diaphragm : the ganglion on the right side is beneath the vena cava. Irregular in shape, the mass is oval, or divided into smaller ganglia : from its outer side nerves are directed to the kidney and the suprarenal capsule. Offsets of the plexus. The nerves supplied to the viscera form plexuses around the vessels ; thus there are coeliac, mesenteric, renal, spermatic, diaphragmatic, &c. JDiaphragmatic plexus. This plexus comes from the upper part of the semilunar ganglion, but it soon leaves the artery to enter the substance of the diaphragm : a communication takes place between the phrenic nerve of the cervical plexus (p. 80) and these branches of the sympathetic. On the right side is a small ganglion where the plexus is joined by the spinal nerve ; and from it filaments are supplied to the vena cava and the supra- renal body. The ganglion is absent on the left side. (Swan.) The suprarenal ?ierves are very large and numerous, in comparison with the size of the part supplied, and are directed outwards to the suprarenal body. One of the splanchnic nerves communicates with this plexus. The renal plexus is derived from the semilunar ganglion and outer part of the plexus, and is joined by the smallest splanchnic nerve. The nerves surround the renal artery, having small ganglia on them, and enter the kidney with the vessels. An offset is given from the renal to the sper- matic plexus (p. 443). The cceliac plexus is a direct continuation of the plexus around its artery: it is joined by the small splanchnic nerve on each side, and by an offset from» the right pneumo-gastric nerve. The plexus divides like the artery into three parts — coronary, splenic, and hepatic. a. The coronary plexus accompanies the vessel of the same name to the upper border of the stomach, where it ends : it communicates with the left vagus nerve. b. The splenic plexus furnishes offsets to the pancreas, and to the stomach along the left gastro-epiploic artery : and it is joined by an offset from the right pneumo-gastric nerve. c. The hepatic plexus is continued on the vena portoe, the hepatic artery, and the bile duct into the liver, and ramifies on those vessels : in the small omentum, the plexus is joined by offsets from the left vagus. The follow- ing secondary plexuses are furnished around the branches of tlie hepatic artery, and have the same name and distribution as the vessels : — A pyloric plexus is distributed along the upper border of the stomach. 452 DISSECTION OF THE ABDOMEN. Two other plexuses — gastro-epiplo'ic (right) and pancreatico-duodenal, correspond in distribution with the branches of each artery. A cystic plexus ramifies in the coats of the gall bladder with its artery. The remaining oflfsets of the plexus, viz., superior and inferior mesen- teric, aortic, and spermatic, have been already noticed (p. 443) ; but the derivation of the superior mesenteric and aortic plexuses from tlie epigas- tric centre can be now seen. Ending of the splanchnic nerves. The large nerve perforates the crus of the diaphragm, and generally ends altogether in the semilunar gan- glion. The small nerve comes through the same opening in the diaphragm as the preceding, and joins the coeliac plexus. The smallest nerve, which is often absent, throws itself into the renal plexus. Ending of the vagus nerve. The pneu mo-gastric nerves end in the stomach : — The left nerve divides into branches, which extend along the small cur- vature, and over the front of the stomach ; these send offsets to the hepatic plexus. The right nerve is distributed to the posterior surface of the stomach near the upper border ; it communicates with its fellow, and with tiie coeliac and splenic plexuses. Dissection. The viscera are now to be removed from the abdomen, in order that the body may be turned ibr the dissection of the Back and lower limbs. The stomach and the spleen, with the duodenum and the pancreas, are to be taken away together by cutting through the oeosphagus near the dia- pliragm, as well as the vessels and nerves they receive. The liver is to be removed from the abdomen by dividing its ligaments, and incising the vena cava between the posterior border and the diaphragm. At the same time the left testicle, and the right kidney with the supra- renal body, should be removed for examination whilst the body is turned ; the former can be taken out by cutting through the spermatic cord, and tlie latter by dividing the vessels about the middle. Directions. Supposing the body to be now turned for the dissection of the Back, and to lie with the face downwards for the usual time, the dissector may look first to the fascia lumborum, which is described in the Dissection of the Back, p. 357. The rest of the time should be occupied in learning the viscera included in the followins Section. Section IV. ANATOMY OF THE VISCERA OF THE ABDOMEN. THE STOMACH. The stomach is the dilated part of the alimentary tube between the oesophagus and the small intestine, into which the masticated food is re- ceived to be changed into chyme. 'Dissection. To see the form, the stomach must be blown up moder- STRUCTURE OF STOMACH. 453 ately, and the surface cleaned ; but, previously, let the student detach the spleen, and cut through the duodenum close to the pylorus. Forms and Divisions. The stomach is somewhat conical in form (fig. 147). Its size varies much in different bodies, and is sometimes much diminished by a constriction in the centre; when it is moderately dis- tended, it is about twelve inches long and four wide. There are two ends, two orifices, two surfaces, and two borders or curves to be examined. Extremities. The left end or tuberosity (fundus ventriculi) is the largest part of the stomach, and projects about three inches to the left of the opening of thb oesophagus. The right or pyloric end, much smaller than the other, is cylindrical, and forms the apex of the cone to which the stomach is likened. Openings. The left opening (cardiac), which communicates with the oesophagus, is at the highest part of the stomach, and is funnel-shaped towards the cavity of the organ. The right or pyloric orifice opens into the duodenum, and is guarded internally by a muscular band (pylorus) : at the same spot the stomach is slightly constricted externally, where a firm circular ring may be felt. Surfaces. The surfaces (anterior and posterior) are somewhat flattened when the viscus is empty, but rounded when it is distended : the parts in contact with them have been referred to (p. 431). Borders. The upper border or small curve is concave towards the left opening, but convex at the opposite end ; and the lower border or large curve is convex, except near the right end, where it is concave — the con- cavity of the one border corresponding with the convexity of the other. An arterial arch, and a fold of peritoneum (omentum) are fixed to each border. Structure. In the wall of the stomach are four coats, viz., serous, muscular, fibrous, and mucous ; and belonging to these there are vessels, nerves, and lymphatics. Serous coat. The peritoneum gives a covering to the stomach, and is adherent to the surface, except at each margin, where an interval exists corresponding w^ith the attaclmient of the small and large omentum : in those spaces are contained the vessels, nerves, and lymphatics. During distension of the stomach the spaces above mentioned are much di- minished. The muscular coat will be laid bare by the removal of the serous cover- ing. It consists of three sets of fibres — longitudinal, circular, and oblique ; these lie from without inwards in the order mentioned, and are unstriated or involuntary. The longitudinal fibres (fig. 147, a) are derived from the oesophagus; they spread over the surfaces, and are continued to the pylorus and the small intestine. The fibres are most marked along the borders, particu- larly at the smaller one; and at the pylorus they are stronger than in the centre of the stomach. • The circular fibres (fig. 147, b) form the middle stratum, and will be best seen by removing the longitudinal fibres near the pylorus. They reach from the left to the riglit end of the stomach ; but at the pylorus they are most numerous and strongest, and form a ring or sphincter {c) around the opening. The oblique fibres (fig. 147, e) are continuous with the circular or deep layer of the oesophagus. On the left and right of the cardie orifice they are so arranged as to form a kind of sphincter {d and e) (Henle); but 454 DISSECTION OF THE ABDOMEN. those on the left (e), the strongest, arch over the great end of tlie stomach, and spread out on the anterior and posterior surfaces, gradually disappear- ing on them. Fibrous coat. By removing the muscular layer over a small space, the fibrous coat will appear as a white shining stratum of areolar tissue. This coat gives strength to the stomach, and serves as a bed in which the larger vessels and nerves ramify before their distribution to the mucous layer. If a small opening is made in this membrane, the mucous coat will project through the stomach to be distended with air. Fig. 147. Diagram Repbesenting the Arrangement of the Muscular Fibres of the Stomach. Part of each of the two external coats is removed. o. External or longitudinal fibres. c. Oblique fibres, more numerous, on the right of h. Middle or circular. the cardiac orifice, and covering the great c. Sphincter of the pylorus. end of the stomach. d. Oblique fibres on the left of the cardiac opening. The mucous coat will come into view on cutting open the stomach, but the appearances now described can be recognized only in a recent stomach. This coat is a thickish layer, of a pale rose color soon after death in the healthy condition. In the empty state of the stomach the membrane is less vascular than during digestion ; and in infancy the natural redness is greater than in childhood or old age. When the stomach is contracted the membrane is thrown into numerous wavy ridges or rugcB, which become longitudinal along the great curve, towards the pylorus. The thickness of the mucous membrane is greatest near the pylorus ; and at that spot it forms a fold, oj)])Osite the muscular ring, which assists in closing the o})ening. If this membrane and its submucous layer are removed from the pyloric part of the stomach, the ring of muscular fibres (sphincter of the pylorus) will be more perfectly seen. Microscopic -structure of the mucous membrane. With the aid of a lens, the surface of the mucous membrane, when well washed, may be seen to be covered by shallow depressions or alveoli (fig. 148), which measure from ^^(jtli to 1 igth of an inch across. Generally hexagonal or polyjro- nal in outline, the hollows become larger and more elongated towards the small end of the stomach ; and near tlie pylorus the margins of the alveoli project, and become irregular. In the bottom of each depression are the apertures of minute tubes. STRUCTURE OF STOMACH 455 By means of a thin section under the microscope the membrane may be observed to be composed almost altogether of minute vertical tubes, which lie side by side, and project into the submucous tissue. Measuring from ^^eculiarity has been described at p. 438. The muscular coat is constructed of two sets of fibres, a superficial or longitudinal, and a deep or circular. The fibres are pale in color, and are not striated. The longitudinal fibres form a thin covering, which is most marked at the free border of the gut. The circular fibres are much more distinct than the others, and give the chief strength to the muscular coat : they do not form complete rings around the intestine. Dissection. On the removal of a part of the muscular stratum from the jejunum or the ileum, the submucous fibrous layer will come into view. The fibrous coat has the same position and use as the corresponding layer in the stomach. Dissection. In tlie upper part of the duodenum the student is to seek some small compound glands — those of Brunner, which are imbedded in the submucous tissue. They lie beneath the mucous membrane, and will COATS OF SMALL INTESTINE, 457 be seen shining through the fibrous hiyer, wlien the muscular coat has been taken away. The pieces of intestine may be opened and washed to sliow the mucous coat, but the gut should be cut along the line of attachment of the mesen- tery, so as to avoid Peyer's glands on the opposite side. Mucous coat. The lining membrane is thicker and more vascular at the beginning than at the ending of the small intestine. It is marked by numerous prominent folds (valvulsB conniventes) ; and the surface of the membrane is covered with small processes (villi) like the pile of velvet. Occupying the substance of the mucous coat are numerous glands ; and covering the whole is a columnar epithelium. A thin layer of non-striated muscular fibres (muscularis mucoscB) covers the outer surface of this coat (fig. 154, c?), and sends inwards prolonga- tions between the tubules into the villi. The valvnlce conniventes (fig. 150) (valves of Kerkring) are permanent ridges of the mucous membrane, which are arranged circularly in the intestine, and project into the alimentary mass. Crescentic in form, they extend round the intestine for half or two-thirds of its circle, and Fig. 150. Tre Duodenum opened showing the Vax,vul;e Conniventes, and the opknino of the Bile Duct. The duct of the paucreas is also represeated ia greater part of its course. a. Duodenum. d. Pancreatic duct. 6. Pancreas. e. Opening of the common duct in the intestine c. Common bile duct. (Henle). some end in bifurcated extremities. Larger and smaller folds are met with, sometimes alternating ; and the larger are about two inches long, with one-third of an inch in depth towards the centre. Each is formed of a doubling of the mucous membrane, which incloses vessels between the layers. They begin in the duodenum, about one or two inches beyond the py- lorus, and are continued in regular succession to the middle of the jeju- num; but beyond that point they become smaller and more distant from one another, and finally disappear about the middle of the ileum, having previously become irregular and rudimentary. The folds are largest and most uniform beyond, and not far from the o{)ening of the bile duct. The aperture of the common bile and pancreatic ducts (fig. 150, e) is a 458 DISSECTION OF THE ABDOMEN. narrow orifice, from three to four inches from tlie pylorus, and is situate in a small prominence of the mucous membrane, at the inner and posterior part of the duodenum (p. 445). A probe passed into the bile duct will show the oblique course (half an inch) under the mucous coat. Some- times the pancreatic duct opens by a distinct orifice. Microscopic structure of the mucous membrane. With the use of the microscope, and with pieces of fresh intestine, the student will be able to make out the nature of the villi, the glandular bodies, and the epithelium. Villi, When a piece of the lower part of the duodenum, from which the mucus is M'ashed away, is examined in water, the mucous membrane will be seen to be studded over thickly with small projections, like those on velvet. These bodies exist along the whole of the small intestine, and are irregular in form (fig. 153, ^) some being triangular, others conical or cylindrical with a large end. Their length is from ^'^jth to ^^-th of an inch ; and they are best marked where the valvular conniventes are largest. In the duodenum their number is estimated at 50 to 90 in a square line, but in the lower end of the ileum at only 40 to 70 on the same surface (Krause). Each villus is an extension of the mucous coat, and is covered by col- umnar epithelium. One or sometimes two arterial twigs form a capillary network beneath the mucous covering (fig. 144, ^), and end generally in a single emerging vein. A single lacteal, or two forming a loop with cross branches (fig. 151, ^), occupies the centre, and communicates with Fig. 151. A. Vessels of the Villi in the Mouse, In- jected BY Gerlach (KoUicker). a. Artery, aud b, vein. B. LACTEALS and Pl-KXUS OF VESSELS IN TWO Villi, Injected by Teichman. a. Lacteal vessel, sinjjle in one villus, double in the other. b. Plexus of vessels. c. Plexusoflacteals below the villi. (Quain's Auatoiuy.) plexus below the villus. Around the lacteals a thin layer of unstriated muscular fibre is arranged longitudinally (Briicke). Nerves have not been detected in the villus. Glands. In the glandular apparatus of the small intestine are included PATCHES OF PEYER. 459 the crypts of Lieberkiihn, solitary glands, and Peyer's and Brunner's glands. The crypts of Lieherkilhn (fig. 154, a) are minute simple tubes, similar to those in the stomach, though not so closely aggregated, which exist throughout the small intestine. They open on the surface of the mucous membrane by small orifices between the villi, and around the larger glands ; but closed at the opposite end, they project into the submucous layer, and are seldom branched. Their length is from ^^^th to g^th of an inch : they are filled with a translucent fluid containing granules, and are lined by a columnar epithelium. The so-called solitary glands (fig. 153, ®) are roundish white eminences, about the size of mustard seed if distended, which are scattered along the small intestine, but in greatest numbers in the ileum. Placed on all parts of the intestine, and even on or between the valvulas conniventes; they are covered by the villi of the mucous membrane, and are surrounded at Fie?. 152. A. Patch of Peter's Glands four times en- LAROKD. a. Surface of the mucous membrane covered with villi. b. Pits over the follicles where the villi are ab- sent. MAaNiPiEi> Representation of an Injec- tion IN the Rabbit, by Fret, op the Vessels SuRROUNDrsa and Penetratino TH K Follicles in a Patch of Peter (KoI- licker). the'r circumference by apertures of the crypts of Lieberkiihn. They are closed lymph follicles beneath the mucous coat, which project into the gut; and they are formed of a network of reticular connective tissue with lymph-corpuscles between the meshes. Fine capillary vessels permeate the mass; and it is surrounded by a plexus of lymphatic vessels. The glands of Peyer (fig. 153, ^) (glanduloe agminatoe) exist chiefly in the ileum, in the form of oval patches, which measure from half an inch to two inches or more in length, and about half an inch in width. They are situate on the part of the intestine opposite to the attachment of the mesentery, and their direction is longitudinal in the gut: usually they are from twenty to thirty in number. In the lower part of the ileum they are largest and most numerous; but they decrease in number and size up- 460 DISSECTION OF THE ABDOMEN wards from that spot, till at the lower part of the jejunum they become irregular in form, and may consist only of small roundish masses. The mucous membrane over them is hollowed into pits (fig. 152, J), and is generally destitute of villi on the subjacent follicles (fig. 153, *), but between the pits it has the same characters as in other parts. Fig. 153. %■ &???« •c>; A. A PIECE OP MtTcors Membrane enlarcied, with its villi and tubules. Tart of a patch of Peyer's glands is also represented with the follicles (a), each having a ring of tubes at the cir- cumference. B. A " solitary gland" of the small intestine, also enlarged, covered by villi (Boebm). A patch, when examined by the microscope, appears to be but a collec- tion of lymph follicles like the *' solitary glands" (fig. 153), which are round or oval in form, and are covered by the mucous membrane. Around each follicle is a ring of apertures of the crypts before described. The follicles have the same composition as the scattered "solitary glands." Fine arterial twigs (fig. 152, ^) ramify on the follicles, and send inwards capillary offsets which form a network in the inte- rior, and converge to the centre. Lacteal vessels form plexuses around and beneath the follicle, but do not penetrate the wall. The Glands of B runner (fig. 154, b) are small compound bodies, similar to the buc- cal and labial glands of the mouth, which exist in the duodenum. For a few inches near the pylorus they are most numerous, and there they are visible without a lens, being nearly as large as hemp seed. The glands consist of lobules, with appertaining excretory tubes : and each ends on the sur- face of the mucous membrane by a duct (c), whose aperture is slightly larger than the mouths of the contiguous crypts of Lieberkiihn; they secrete mucus. Epithelium. The epithelial lining of the mucous membrane of the small intestine is of the columnar or cylindrical kind. On the villi it forms a distinct covering of elongated pieces. It sinks into the crypts Magnified View of the Mucous Membrane of thr Duodenum, with the tubules of LieberkUhn and a gland of Brunner. (t. Tubules. h. Gland of Brunner. c. Duct of the gland. d. Submucous layer of muscular fibres (KOUlker). LARGE INTESTINE. 461 of Lieberkiihn, and into the ducts of the glands of Brunner, and gives them a lining. Dissection. To demonstrate the areolar tissue between the coats of the intestine, a piece of the bowel turned inside out is to be inflated forcibly ; and to insure the success of the attempt, a few cuts may be previously made through the peritoneal coat. The air enters the wall of the intes- tine where the peritoneal covering is injured, and spreads through the whole gut ; but opposite the solitary glands, and the patches of Peyer, the mucous coat is more closely connected with the contiguous structures, and the subjacent portion will not be distended with the air. The piece of the intestine may be examined when it is dry. Vessels of the intestine. The branches of arteries ramify in the sub- mucous layer, and end in a network of small twigs in the mucous mem- brane, which supplies the folds, the villi, and the glands. Opposite Peyer's patches the intestine is most vascular ; and the vessels form circles around the follicles, before supplying offsets to them. The veins have their usual resemblance to the companion arteries. The absorbents consist of a superficial set (lymphatics) in the muscular coat ; and of a deep plexiform set (lacteals) in both the mucous and sub- mucous layers. The two sets join, and all end in larger trunks in the mesentery. Nerves of the small intestine come from the upper mesenteric plexus, and entering the coats by the side of the arteries, form plexuses with in- terspersed ganglia. One such plexus is contained in the muscular coat between the longitudinal and circular fibres (Auerbach) ; and another is placed in the submucous layer (Meissner) : they join freely by branches through the intestinal coats, and reach from the pylorus to the extremity of the alimentary tube. Structure of the common bile duct. The bile duct consists of an exter- nal or strong fibrous layer, and of an internal or mucous coat which is lined by columnar epithelium. On the surface of the inner membrane are the openings of numerous branched mucous glands, which are imbedded in the fibrous coat ; some of them are aggregated together, and are visible with a lens. LARGE INTESTINE. The large intestine is the part of the alimentary canal between the termination of the ileum and the anus. Its division and its attachment by peritoneum to the abdominal wall, have been described (p. 483). In length this part of the alimentary canal measures about five or six feet — one-fifth of the length of the intestinal tube. The diameter of the colon is largest at the commencement in the caecum, and gradually de- creases as far as the rectum, wliere there is a dilatation near the end. When compared with the small intestine, the colon is distinguished by the following characters : It is of greater capacity, being in some parts as large again, and is more fixed in its position : it is also free from convolu- tion, except in the left iliac fossa, where it forms the sigmoid flexure. Instead of being a smooth cylindrical tube, the colon is sacculated, and is marked by three longitudinal muscular bands, which alternate with as many rows of dilatations ; but at the lower part of the large intestine (rectum), the surface is smooth, and the longitudinal bands have disap- peared. Attached to the surface at intervals, especially along the trans- 462 DISSECTION OF THE ABDOMEN. Fiff. 155. verse colon, are processes of peritoneum containing fat — the appendices epiploicae. Dissection, For the purpose of examining the large intestine the student should cut off and blow up the caecum, with part of the ileum entering it ; he should prepare in a similar way a piece of the transverse colon, and a piece of the sigmoid flexure (about four inches of each). The areolar tissue and the fat are to be removed with care from each, after it has been inflated. The CJECUM, or the head of the colon (fig. 155, a) (caput crecum coli) is the rounded part of the large intestine which projects, in the form of a pouch, below the junction of the ileum with it. It measures about two inches and a half in length, and tliough gradually narrowing iriferiorly, the caecum is the widest part of the colon — hence the name caput coli. At its inner side it is joined by the small intestine (/>) ; and still lower there is a small worm-like projection (c) — the ver- miform appendix. Appendix vermiformis (fig. 155, c). This little convoluted projection is attached to tlie lower and hinder part of the caecum, of wliich it was a continuation, at one period, in tlie embryo. From three to six inches in length, the appendix is rather larger than a goose- quill, and is connected to the inner part of the caecum by a fold of peritoneum. It is hollow, and has an aperture of communica- tion with the intestine (d). In structure it resembles the rest of the colon. Dissection. To examine the interior of the csecum, and the valve between it and tlie small intestine, the specimen should be dried, and tlie following cuts should be made into it: One oval piece is to be taken from the ileum near its termination ; another from the side of the caecum, opposite the entrance of the small intestine. lleo-ccecal valve (fig. 155). This valve is situate at the entrance of tlie ileum into the csecum. It is composed of two pieces, each with a different inclination, which project into the interior of the caecum, and bound a narrow, nearly transverse aperture of communication between the two differently-sized portions of the alimentary canal. The upper piece of the valve, ileo-colic {e) projects horizontally into the large intestine, opposite the junction of the ileum with the colon. And the lower piece, ileo-coecal (/), which is the larger of the two, has a ver- tical direction between the ileum and the caecum. At each extremity of the opening the pieces of the valve are blended together; and the result- ing prominence {g) extends transversely on each side of the intestine, forming ih^frcBna or retinacula of the valve. Interior of a Caecum dkiep and laid open. «• Caecum. 6. Small intestine- c. Vermiform appendix, and d, its aperture. e. Ilio-colic piece of the valve at the junction of the small in- testine, /. Ilio-caecal piece of the valve. g. Retinaculum of the valve on each side. STRUCTURE OF THE COLON. 463 The size of the opening depends upon the distension of the intestine ; for when the retinacuhi of the valve are stretched the margins of the aperture are approximated, and may be made to touch. Each piece of the valve is formed by circular muscular fibres of the in- t'?stinal tube, covered by mucous membrane ; as if the ileum was thrust obliquely through the wall of the csecum, after being deprived of its peri- toneal coat and layer of longitudinal fibres. This construction is easily seen on a fresh specimen by dividing the peritoneum and the longitudinal fibres, and gently drawing out the ileum from the caecum. The opening of the appendix into the csecum {d) is placed below that of the ileum. A piece of mucous membrane partly closes the aperture, and acts as a valve. Folds or ridges are directed transversely in the interior of the gut, and correspond Avith depressions on the outer surface : these folds result from the doubling of the wall of the intestine, and the largest inclose vessels. Structure of the Colox. The coats of the large are similar to those of the small intestine, viz., serous, muscular, fibrous, and mucous. Serous coat. The peritoneum does not clothe the large intestine, throughout, in the same degree. It covers the front of the caecum, and the front and sides of the ascending and descending colon ; but in neither does it reach commonly the posterior aspect (p. 438). The transverse colon is incased like the stomach, and has intervals along the borders, where the transverse meso-colon and the great omentum are attached. The muscular coat is formed by longitudinal and circular fibres, as in the small intestine. The longitudinal fibres may be traced as a thin layer over the surface, but most are collected into three longitudinal bands, about a quarter of an inch in width. On the vermiform appendix the fibres form a uniform layer ; but they are continued thence into the bands on the c^cum and colon : on the rectum tliey are diffused over the surface. When the bands are divided the intestine elongates — the sacculi, and the ridges in the interior of tlie gut, disappearing at the same time. The circular fibres are spread over the whole surface, but are most marked in the folds projecting into the intestine. In the rectum (to be afterwards seen) they form the band of the internal sphincter muscle. Th^ fibrous coat resembles that of the small intestine. It will be ex- posed by removing the peritoneal and muscular coverings. The mucous coat^ which may be examined on opening the intestine, is smooth, and of a pale yellow color; and it is not thrown into special folds, except in the rectum. The surface is free from villi ; and by this circum- stance the mucous membrane of the large, can be distinguished from that of the small intestine. This difference in the two portions of the alimen- tary tube is well marked on the ilio-c«cal valve ; for the surface looking to the small intestine is studded with villi, whilst the lower surface, covered by the lining membrane of the caecum, is free from those small eminences. Microscopic appearances. In a piece of fresh intestine the microscope will show the mucous membrane to possess small tubes or crypts, and some larger solitary follicles; with an epithelial covering on the free sur- face, and a thin muscular layer {muscidaris mucosae) on the other, whose arrangement is similar to that of the small intestine. The tubules (fig. 156, ^) occupy the whole length of the large gut, and resemble those of the small intestine, but are more numerous and closer together. Their orifices on the surface are circular ('), and are more uni- 464 DISSECTION OF THE ABDOxMEN. formly diffused than the apertures of the tubules in the small gut. A vertical section of the membrane (^) will show the tubes to ex- tend vertically from the surface into the sub- mucous coat, and to be longer than the crypts of Lieberkiihn in the jejunum and ileum ; they measure from ^^^th to ^j^^th of an inch in length. The so-called solitary glands (fig. 156, ^) are scattered here and there througli the large intestine ; but they are in greatest number in the caecum and vermiform appendix. They are whitish rounded bodies from -^^ih to y^^th of an incli in diameter, and are situate in the submucous layer amongst the tubules. They are lymph follicles with a structure like that in the small intestine. The epithelium is of the columnar kind, and enters the tubules. The distribution of the vessels in the wall of the large intes- tine is the same as in the smaller bowel. Nerves. In the coats of the large intestine the nerves have the plexi- form arrangement like that in the small gut. The absorbent vessels form two sets as in tlie small intestine; after leav- ing the gut they join the lymphatic glands along the side of the colon. Enlarged View of "a Solitary Gland," and of the tubules of the mucous coat. (Boehra.) A. Gland of the large intestine. B. Tubules of the mucous mem- brane. 1. Surface opening. 2. Side view of the tubes. 3. Pits for the closed ends of the tubes in the submucous tissue. THE PANCREAS. The pancreas (fig. 145, e) is a narrow flattened gland, from six to eight inches in length, which has some resemblance to a dog's tongue. It is larger at the right than the left end ; and it is divided into head, tail, and body. The head^ or the right extremity, occupies the concavity of the duo- denum; and the left extremity, or the tail, is rounded, and touches the spleen. The body of the gland is narrowest a little to the right of the vertebral column, and is thickest at the upper border ; it measures about one incii and a half in breadth, and from half an inch to an inch in thickness. The connections of the pancreas with surrounding parts are described at p. 446. Dissection. Let the pancreas be placed on the anterior surface, and let the excretory duct be traced from the head to the tail by cutting away the substance of the gland. The small duct will be recognized by its whiteness. Structure. The pancreas is a gland consisting of separate lobules, and is provided with a special duct. It is destitute of a distinct capsule ; but it is surrounded by areolar tissue, which projects into the interior, and connects together its smaller pieces. The fluid secreted by it assists in the digestion of the aliment. The lobules are soft and loose, and of a grayish-white color, and are united into larger masses by areolar tissue, vessels, and ducts. Each con- sists ultimately, as in the parotid, of the branchings of the excretory duct, which end in closed vesicular extremities, and are surrounded by a plexus of vessels. In the vesicles the epithelium is spheroidal. THE SPLEEN. 465 The duct of the pancreas (fig. 150, d) (canal of Wirsung) extends the entire length of the gland, and is somewhat nearer the lower than the upper border. It begins in the tail of the pancreas, where it presents a bifurcated extremity; and as it continues onwards to the head, it receives many branches. It finally ends by opening into the duodenum, either in union with, or separate from the common bile duct (p. 457). Of the tribu- tary branches, the largest is derived from the head of the pancreas. The duct measures from y^^th to yV^^^ ^^ ^" moh. in diameter near the duodenum. It is formed ol' a Jibrous and a mucous coat : the latter is lined by a cylindrical epithelium^ and is provided with small glands in the duct and its largest branches. Vessels^ lymphatics, and nerves. The arteries and veins have been described (p. 447); and the lymphatics join the lumbar glands. The nerves are furnished by the solar plexus. THE SPLEEN. The spleen is a vascular spongy organ of a bluish or purple color, some- times approaching to gray. Its texture is friable, and easily broken under pressure. The use of the spleen is unknown. The viscus is somew^iat elliptical in shape, and is placed vertically against the great end of the stomach. Its size varies much. In the adult it measures commonly about five inches in length, three or four inches in breadth, and one inch to one inch and a half in thickness. Its weight lies between four and ten ounces, and is rather less in the female than the male. At the outer aspect it is convex towards the ribs, the inner surface is marked by a longitudinal ridge, nearer the posterior than the anterior border, into which the vessels plunge to ramify in the interior. Before and behind the ridge, the surface is flattened or somewhat hollowed. The spot where the vessels enter is named the hilum of the spleen. The anterior border is thinner than the posterior, and is often notched. Of the two extremities, the lower is more pointed than the upper. Small masses or accessory spleens (splenculi), varying in size from a bean to a moderate-sized plum, are found occasionally, near the fissure of the spleen, in the gastro-splenic omentum, or in the great omentum. Structure. Enveloping the spleen are two coverings, a serous and a fibrous. It is formed by a network of fibrous or trabecular tissue, which contains in its meshes the splenic pulp, with the Malpighian corpuscles. Throughout the mass the bloodvessels and the nerves ramify. No duct exists in connection with this organ. The serous or peritoneal coat incases the spleen, and covers the surface except at the hilum and the posterior border. It is closely connected to the subjacent fibrous coat. The, fibrous coat (tunica propria) gives strength to the spleen, and forms a complete case for it. At the fissure on the inner surface this investment passes into the interior with the vessels, to which it furnishes sheaths : and if an attempt is made to detach this coat, numerous fibrous processes will be seen to be connected with its inner surface. Its color is whitish ; and its structure is made up of areolar and elastic tissues. Dissection. The spongy or trabecular structure will best appear, by washing and squeezing a piece of fi-esh bullock's spleen under water, so as to remove the grumous-looking material. 30 466 DISSECTION OF THE ABDOMEN The trabecular tissue (fig. 157) forms a network througli the whole in- terior of the spleen, similar to that of a sponge, wliich is joined to the external casing, and forms sheaths around the vessels. Its processes or threads are white, flattened or cylindrical, and average from -r^^th to ^'^th of an inch : they consist of fibrous and elastic tissues, with a tew muscular fibres. The interstices communicate freely together, and contain the proper substance of the spleen, and the vessels. Microscopic appearances. The characters of the spleen substance can- not be ascertained without the aid of the microscope. The splenic pnlp is a soft red-brown mass, which is lodged in the areolae of the trabecular structure. Under the microscope this material is seen to be composed of a fine network of ramifying connective tissue corpuscles, with blood-cells in its meshes. The Malpighian corpuscles are small rounded whitish bodies, about e'jth of an inch in diameter, and are connected with the outer coat of the smallest branches of the arteries ; they project into the pulp of the spleen, and are surrounded by it. In structure they are like the lymph follicles of the intestine, consisting of reticular tissue, with lymph corpuscles in its meshes, through which blood-capillaries pass. Bloodvessels. Tiie larger branches of the splenic artery are surrounded by sheaths of fibrous tissue in the trabecula3 ; but the smallest branches leave the sheathing, and break up into tufts of capil- laries, which open into the fine meshes of the spleen substance. In the smallest branches, with which the Malpighian corpuscles are united, the outer coat is thickened by lymphoid tissue, and is directly continuous with those bodies in structure. The splenic vein begins in the meshes of the splenic pulp by open channels. From the union of these radicles arise small branches, which unite into trunks larger than the accompanying arteries, and issue by the fissure of the spleen ; in their course they receive acces- sory branches, some joining at a right angle. Nerves and lymphatics. The lymphatics are superficial and deep, and enter the glands in the gastro-splenic omentum. In the spleen they begin in the corpuscles of Malpighi, and in the outer coat of the smallest arteries ; they are conveyed to the hilum of the spleen on the vessels. The nerves come from the solar plexus, and surround the artery and its branches. A Drawing of thr Tra- becular Structurk of THE Spleen of the Ox, at some distance from the hilum. THE LIVER. The liver secretes the bile, and is the largest gland in the body. Its duct opens into the duodenum with that of the ])ancreas. Dissection (fig. 158). Preparatory to examining the liver, the vessels at the under surface should be dissected out. This proceeding will be facilitated by distending the vena cava and vena, porta; with tow or cotton wool, and tlie gall-bladder with air through its duct. The several vessels and the ducts are then to be defined, and the gall-bladder to be cleaned. LOBES AND FISSURES OF LIVER. 467 On following outwards the left branch of the vena portae to the longi- tudinal or antero-posterior fissure, it will be found united anteriorly with the round ligament or the remains of the umbilical vein, and posteriorly with the fine fibrous remnant of the ductus venosus. The liver is of a red-brown color and firm consistence ; and weighs commonly in the adult from three to four pounds (fifty to sixty ounces). Transversely the gland measures from ten to twelve inches ; from front to back between six and seven inches; and in thickness, at the right end, about three inches ; but this last measurement varies with the spot ex- amined. In shape the liver is somewhat square. It has many named parts, viz., two surfaces, two borders, and two extremities ; and the under surface is further marked by lobes and fossae, and by fissures which contain vessels. The connections and the ligaments of the liver are described at p. 434 and p. 438. Surfaces. On the upper aspect the liver is convex : extending from front to back in the suspensory ligament, which divides the upper surface into two unequal parts, of which the right is the larger. The under sur- face is rendered irregular by lobes, fissures, and fossa? : in contact with it is the gall-bladder ; and a longitudinal sulcus divides it into a right and a left lobe. Borders. The anterior border is thin, and is marked by two notches : one is opposite the longitudinal sulcus on the under surface before alluded to, and the other is over the large end of the gall-bladder. The posterior border is much thicker at the right than at the left end ; and at the thick- ened part it touches the right kidney and the diaphragm. Opposite the vertebral column is a hollow in this border ; and the vena cava is partly imbedded in it on the right of the spine. Extremities. The right extremity is thick and rounded; and the left is tliin and flattened. Lobes. On the under surface the liver is divided primarily into two lobes, a right and a left, by the antero-posterior or longitudinal fissure ; and occupying this surface of the right lobe are three others, viz., the square, tlie Spigelian, and the caudate lobe : — The left lobe. «, is smaller and thinner than the right, and there is a slight depression inferiorly where it touches the stomach. The right lobe, a, forms the greater part of the liver, and is separated from the left by the longitudinal fissure on the one aspect, and by the sus- pensory ligament on the other. To it the gall-bladder is attached below ; and the following lobes are projections on its under surface : — The square lobe, c (lobulus quadratus), is situate between the gall- bladder and the longitudinal fissure. It reaches anteriorly to tlie margin of the liver, and posteriorly to the fissure (transverse) by which the ves- sels enter the interior of tlie viscus. The Spigelian lobe, d, lies behind the transverse fissure, and forms a roundish projection on the surface. On its left side is the longitudinal fissure; and on its right, the vena cava inferior. The caudate lobe, e, is a slight, elongated eminence, which is directed from the Spigelian lobe behind tlie transverse fissure, so as to form the posterior boundary of that sulcus. Where the fissure terminates this pro- jection subsides in the right lobe. Fissures. Extending horizontally half across the right part of the liver between the Spigelian and caudate lobes on the one hand, and the square 468 DISSECTION OF THE ABDOMEN lobe on the other, is the transverse or portal fissure. It is situate nearer the posterior than the anterior border, and contains the vessels, nerves, ducts, and lymphatics of the liver. At tiie left end it is united at a right angle with the longitudinal fissure. Fig. 158. Under Surface of the Liver. A. Kight, and B, left lobe. c. Quadrate lobe. D. Spigelian, and e, caudate lobe. F. Longitudinal fissure. G. Gall-bladder. a. Vena cava. 6. Vena portse. c. Round ligament. d. Obliterated ductus venosus. e. Common hepatic duct. /. Cystic duct. g. Common bile duct. h. Hepatic artery. The longitudinal fissure, f, extends from the front to the back of the liver, between the right and left lobes. In the part anterior to the trans- verse fissure lies the remnant of the umbilical vein (c), which is called round ligament, and is oftentimes arched over by a piece of the hepatic substance (pons hepatis). In the part behind that fissure is contained a small obliterated cord (rtf), the remains of the vessel named ductus venosus in the foetus. The groove for the vena cava is placed on the right side of the Spigelian lobe, and is frequently bridged over by the liverl If the cava be opened, two large and some smaller hepatic veins will be observed entering it. FosscB. On the under surface of the right lobe are three depressions — one for the gall-bladder to the right of the square lobe ; another for the colon, near the anterior edge; and a third for the kidney near the posterior border. Vessels of the transverse Jissure. The vessels in the transverse fissure, viz., vena portOR, hepatic artery and duct, have the following position : the duct is anterior, the portal vein posterior, and the artery between the other two. The hepatic duct (fig. 158, e) is formed by two branches from the liver, one from eacli lobe, which soon blend in a common tube. After a distance of one inch and a half it is joined by the duct of the gall-bladder (/) ; and the union of the two gives rise to the common bile duct (^). STRUCTURE OF LIVER. 469 The hepatic artery (h) is divided into two, one for each lobe, and its branches are surrounded by nerves and lymphatics. The veiia portce (h) branches, like the artery, into two trunks for the right and left lobes, and gives an offset to the Spigelian lobe; its left branch is the longest. FcEtal condition of the umhilical vein. Before birth the previous um- bilical vein occupies the longitudinal fissure, and opens posteriorly into the vena cava; the portion of the vessel behind the transverse fissure re- ceives the name ductus venosus. Branches are supplied from it to both lobes of the liver; and a large one, directed to the right lobe, is continuous with the left piece of the vena porta?. Purified or placental blood circu- lates through the vessel at that period. Adult state. After birth the part of the umbilical vein in front of the transverse fissure is closed, and becomes eventually the round ligament (fig. 158, c). The ductus venosus is also obliterated, only a thin cord (d) remaining in its place. Whilst the lateral branches, which are in the same line as, and continuous with the left branch of the vena portce, remain open, and subsequently form part of the left division of the vena portae. Occasionally the ductus venosus is found more or less pervious. Structure of the Liver. The substance of the liver consists of small bodies called lobules or acini; together with vessels which are con- cerned both in the production of the secretion, and in the nutrition of the organ. The whole is surrounded by a fibrous and a serous coat. Serous coat. The peritoneum invests the liver almost completely, and adheres closely to the subjacent coat. At certain spots intervals exist be- tween the two, viz., in the fissures occupied by vessels, along the line of attachment of the ligaments, and at the surface touching the gall-bladder. The jibrous covering is very thin, but it is rather stronger where the peritoneum is not in contact with it. It invests the liver, and is continu- ous at the transverse fissure with the fibrous sheath (capsule of Glisson) surrounding the vessels in the interior. When the membrane is torn from the surface, it will be found connected with fine shreds entering into the liver. Size and form of the lobules. The lobules (fig. 161, /) constitute the proper secreting substance, and can be seen either on the exterior of the liver, on a cut surface, or by means of a rent in the mass. As thus ob- served, these bodies are about the size of a pin's head, and measure from ^^^th to y^^th of an inch in diameter. Closely massed together they pos- sess a dai'k central point; and there are indications of lines of separation between them, though they communicate by vessels. By means of trans- verse and vertical sections of the lobules, their form \Vill appear flattened on the exterior, but many sided in the interior of the liver. Tliey are clustered around the smallest divisions of the hepatic vein, to which each is connected by a small twig issuing from the centre, something like the union of the stalk with the body of a small fruit. To study the minute structure of the lobules, a microscope will be neces- sary ; and the different vessels of the liver should be minutely injected. Constituents of the lobules. Each lobule is composed of minute hepatic cells, which are arranged web-like amongst the ducts and vessels ; and it is provided with a capillary network of vessels, and with a plexus of the bile duct. Cells of the lobules. The hepatic or biliary cells (fig. 159, a) form the chief part of the lobule ; they are irregular in form, being rounded or 470 DISSECTION OF THE ABDOMEN Fig. 159. many sided, and possess a bright nucleus, or even more than one. In size they vary from joVu^^ *^ ^J^^^ of an incli. They are of a yellowish color, and inclose granular particles, together with fat and yellow coloring matter. These nucleated cells adhere together by their surfaces so as to form rows radiating from the centre, with spaces (b) between them for the blood- vessels and ducts. The cells are con- cerned in the secretion of the bile. Vessels of the lobule (fig. 160, b). The smallest branches of the venaportcB, after uniting in a circle around the lo- bule, where they are named interlobular («), enter its substance, and form therein a network of capillaries (c) near the cir- cumference. A small branch of the hepatic vein {d) occupies the centre of the lobule ; its radicles communicate with the portal network, and it issues from the base of A Magnified Reprksf.ntation of the the lobule as the intralobular vein. Hepatic CELLS ^vith their arrange- rpj^^ radicks of the bile duct (fig. 160, ment la the lobule (Henle). . . . ... , i , i . /V . ^ (,gjjg a) begin witlim the lobule in a fine in- 6. Intercellular spaces. tralobular plexus of ducts {g) between Fig. 160. I. Two lobules of the liver showing the plexus of ducts in the interior, near the circum- ference (Kiernan); recent inquiries de- monstrate the existence of a plexus throuu'hout the lobule. g. Intralobular plexus. /. Interlobular ducts. e. Small branches of the hepatic ducts. . Lobules of an injected liver to show tbe arrangement of the veins. «. Smallest branches of the vena portffi end- ing in the interlobular veins, h. c. Plexus of portal veins within the lobule. d. Intralobular commencement of the hepa- tic vein joining the plexus of the portal vein. the hepatic cells (Chrzonszczewsky) ; they leave the lobule at the cir- cumference, and are joined together outside it in the smallest interlobular branches (/). VESSELS AND DUCT OF LIVER 471 From the arrangement of the vessels, it appears that the portal vein conducts the blood from which bile is secreted ; that tiie hepatic vein car- ries away the superfluous blood ; and that the secreted bile is received by the plexus of the biliary duct. Vessels of the Liver. Two sets of bloodvessels ramify in the liver : One enters the transverse fissure, and is directed transversely in spaces (portal canals) where it is enveloped by areolar tissue. The other set (hepatic veins) run from the anterior to the posterior border of the liver without a like sheath. Tlie ramifications of these different vessels are to be followed in the liver. The capsule of Glisson is a layer of areolar tissue, which envelops the vessels and the ducts in the transvei'se fissure. In this sheath the vessels ramify, and in it they are minutely divided before their termination in the lobules. If a transverse section is made of a portal canal, the vessels will retract somewhat into the loose surrounding tissue. The vena portcE ramifies in the liver like an artery ; and the blood cir- culates through it in the same manner, viz., from trunk to branches. After entering the transverse fissure the vein divides into large branches ; these lie in the portal canals or spaces, with offsets of the hepatic artery, the hepatic duct, and the nerves and lym- phatics (fig. 161, p). The division is Fig. 161. repeated again and again until the last branches of the vein {interlobular, fig. 1 60, h') penetrate between the lobules ; there they unite, and end in the interior as before explained. In the portal canals the offsets of the vena portcR are joined by small vagi- nal and surface veins, which convey blood from branches of the hepatic artery. The hepatic artery (fig. 161, c), whilst surrounded by the capsule, fur- nishes vaginal branches, which ramify- in the sheath, giving it a red appear- ance in a well-injected liver, and sup- ply twigs to the coats of the vena portje and biliary ducts, and to the areo- lar tissue : from the vaginal branches a few offsets {capsular) are given to the coat of the liver. Finally the artery ends in fine interlobular branches, from which offsets enter the lobule, and con- vey blood into the network between the branches of the vena portiie and hepatic vein (Chrzonszczewsky). The hepatic vein (vence cava? hepaticje) begins by a plexus in the inte- rior of each lobule (fig. IGO, d), and its smallest radicle issues from the base of the lobule as the intralobular vein ; these are received into the sablobular branches, which anastomose together, and unite into larger vessels. Finally, uniting with neighboring branches to produce larger trunks, the hepatic veins are directed from before backwards to the vena cava inferior, into wdiich they open by large orifices. The venae cavae he- Vesskls in a Portal Canal, and the LoBULKS OF THU LiVER (Kieraan). I. Lobules of the liver. p. Branch of the vena portae, with, a, a, vaginal branches which supply inter- lobular offsets. c. Hepatic artery. d. Hepatic duct. i, i. Openings of the interlobular branches of the portal vein. 472 DISSECTION OF THE ABDOMEN. paticoe may be said to be without a sheath, except in the larger trunks ; so that when they are cut across the ends remain patent, in consequence of their close connection with the liver structure. Hepatic duct (fig. 160, e). The duct commences in the biliary plexus within the lobules. On leaving the lobules the radicles communicate by the interlobular branches (/) ; and the smaller ducts soon unite into larger vaginal branches (o?), which lie in the portal canals with the other vessels. Lastly, the ducts are collected into a right and a left trunk (lig. 158, e), and leave the liver at the transverse fissure.^ Structiwe. The moderately-sized hepatic ducts consist of a fibrous coat, lined by a mucous layer with cylindrical epithelium ; and penetrating the wall is a longitudinal row of openings, on each side, leading into sacs, and into branched tubes which sometimes communicate. In the fine inter- lobular ducts the coat is formed by a homogeneous structure, with colum- nar epithelium (Henle). Lymphatics of the liver are superficial and deep. The superficial of the upper surface join the lympliatics in the thorax by piercing the dia- phragm, and end for the most part in the sternal glands ; those on the under surface enter chiefly the glands by the side of the abdominal aorta, a few uniting with the deep lymphatics, and the coronary of tiie stomach. The deep lymphatics accompany the vessels through the liver, and communicate with one of the large contributing trunks of the thoracic duct. Serves come from the sympathetic and the pneumo-gastric, and ramify with the vessels; but their mode of ending is not ascertained. THE GALL-BLADDER. The gall-bladder (fig. 1G2) is the receptacle of the bile. It is situate in a depression on the under surface of the right lobe of the liver, and to the right of the square lobe. It is pear-slia})ed, and its larger end (fundus) is directed forwards beyond the margin of tlie liver ; whilst the smaller end (neck) is turned in the opposite direction, and bends downwards to termidate in the cystic duct by a zigzag part. In length the gall-bladder measures tliree or four inches, and in breadth rather more than an inch at the widest part. It holds rather more than an ounce. By one surface it is in contact with the liver, and on the opposite it is covered by peritoneum. The larger end touches the abdominal wall oppo- site the tip of the cartilage of the tenth rib, where it is contiguous to the transverse colon ; and the small end is in contact with the duodenum. Structure. The gall-bladder possesses a peritoneal, a fibrous and mus- cular, and a mucous coat. The serous coat is stretched over the under or free surface of the gall- bladder, and surrounds the large end. The Jibrous coat is strong, and forms i\w. framework of the sac ; inter- mixed with it are some involuntary muscular fibres^ the chief being lon- gitudinal, but others circular. • Aberrant ducts 'exist between the pieces of the peritoneum in the left lateral ligament of the liver, and in the pons bridging over the vena port* and vena cava ; they anastomose together, and are accompanied hy branches of the vessels of the liver, viz., vena portse, hepatic artery, and hepatic vein. STRUCTURE OF GALL-BLADDER. 473 Fig. 162. The nnicons coat is marked internally by numerous ridges and interven- ing depressions, which give an areolar or honeycomb appearance to the sur- face. On laying open the gall-bladder this condition will be seen, with the aid of a lens, to be most developed about the centre of the sac, and to diminish towards each extremity. In the bottom of the larger pits are depressions leading to recesses. The surface of the mucous membrane is covered by a columnar epi- thelium. Where the gall-bladder ends in the cystic duct (fig. 162) its coats project into the interior, and give rise to ridges resembling those in the sacculated large in- testine. The cystic duct (b) joins the hepatic duct at an acute angle, to form the ductus communis choledo- chus. It is about an inch and a half long, and is dis- tended and somewhat sacculated near the gall-bladder. Structure. The coats of the duct are formed like those of the sac from which it leads, but the muscular fibres are very few. The mucous lining is provided with glands, as in the hepatic and common bile ducts (p. 472). _ On opening the duct the mucous membrane may be observed to form about twelve semilunar projections (fig. 162, c), which are arranged obliquely around the tube, and increase in size towards the gall-bladder. This structure is best seen on a gall-bladder which has been inflated and dried : as in this state the parts of the duct between the ridges are most stretched. Bloodvessels and nerves. The vessels of the gall- bladder are named cystic. The artery is a branch of the hepatic ; and the cystic vein opens into the vena portoe near the liver. The nerves are derived from the hepatic plexus, and entwine around the vessels. The lymphatics ibllow the cystic duct, and join the deep lymphatics on the spinal column. Gall-Bladder and its Duct a. Gall-bladder. h. Bile duct sacculated. c. Ridges in the interior. d. Common bile duct. c. CommoD hepatic duct. THE KIDNEY AND THE URETER. The kidney has a characteristic form : flattened on the sides, it is larger at the upper than tlie lower extremity, and is hollowed out at one part of its circumference. For the purpose of distinguishing between the right and left kidneys, let the excavated margin be turned to the spinal column, with the ureter or the excretory tube beliind the other vessels ; and let that end be directed downwards, towards which the ureter is naturally inclined. With the special form above mentioned, the kidney is of a deep red color, with an even surface. Its average length is about four inches ; its breadth two ; and its thickness about one inch ; but the left is commonly longer and more slender than the right kidney. Its usual weight is about five ounces and a half in the male, and rather less in the female. The upper extremity of the kidney is rounded, is thicker than the lower, and is surmounted by the suprarenal body. The lower end is flat, and 474 DISSECTION OF THE ABDOMEN Fig. 163. more pointed. The position with respect to the spinal column has been before detailed (p. 435). On the anterior surface the viscus is rounded, but on the opposite sur- face it is generally flattened. The outer border is convex ; but the inner is excavated, and is marked by a longitudinal fissure, hiluni. In the fissure the vessels are thus placed with respect to one another : The divisions of the renal vein are in front, the ureter is behind, and the branches of the artery lie between the two. On the ves- sels the nerves and lymphatics ramify ; and areolar tissue and fat surround the whole. Opposite the fissure is a hollow in the inte- rior of the kidney, named sinus, in which the vessels and the duct are contained be- fore they pierce the renal substance. Dissection. To see the interior it will be necessary to cut through the kidney from the inner to the outer border ; and to remove the loose tissue from the vessels, and from the divisions of the excretory duct. The hollow or sinus containing the bloodvessels now comes completely into view. The interior of the kidney fig. 163) ap- pears on a section to consist of two diffe- rent materials, viz., of an external granular or cortical part ; and of internal, darker colored, pyramidal masses, which converge towards the centre. But these unlike- looking parts are constructed of urine tubes, though with a different arrangement. The pyramidal masses (d) (pyramids of Malpighi), are twelve or eighteen in num- ber, and converge to the sinus of tlie kid- ney. The apex of each mass, which is free from cortical covering, is directed to the sinus, and ends in a smooth, rounded part, named mamilla or papilla (c). In it are the openings of the urine tubes, which are about twenty in num- ber, some being situate in a central depression and the others on the sur- face ; and it is surrounded by one of tiie divisions (calyx) of the excretory tube. Occasionally two of the masses are united in one papillary termina- tion. The base is embedded in the cortical substance, and is resolved into bundles of tubes which are prolonged into the cortical covering. Each pyramidal mass is constructed of uriniferal tubes (tubes of Bellini) which open below at the apex of the papilla (fig. 1G4, a) ; and the cut surface has a grooved apj)earance indicatory of its construction. If the mass is compressed, urine will exude from the tubes through the apertures in the apex. The cortical Qv investing joarf (fig. 163, e) forms about three-fourths of the kidney ; it covers the pyramidal masses with a layer about two lines in thickness, and sends prolongations between the same nearly to their apices. Its color is of a light red, unless the kidney is blanched ; and its consistence is so slight that the mass gives way beneath the finger. In SeotionthrocghtheKidney, show- ing THB Medullary and Cortical Portions, and the beginning op THK Urkter (Heale). a. Ureter, b. Pelvis of the ureter. c. Calyx of tbe excretory tube. d. Pyramidal portions. e. Cortical porcioii of the kidney. EXCRETORY TUBES OF KIDNEY. 475 the injected kidney red points (Malpighian bodies) are scattered amongst the cortex, giving it a granular appearance. Structure of thp: Kidney. The mass of the kidney consists of minute convoluted tubes, intermixed with bloodvessels, lymphatics, nerves, and an intertubular matrix. The whole is incased by a fibrous coat. The Jibrous coat is a white layer, which is connected with the kidney by fine processes and vessels, but is readily detached from it by slight force. At the inner margin of the kidney it sinks into the sinus, and sends processes on the entering vessels and excretory duct. Stroma or matrix. Between the tubules and the vessels of the kidney is a uniting materal, which surrounds and isolates them, and is most abund- ant in the cortical substance. It somewhat resembles areolar tissue in its nature, and is fibrous at some spots. To obtain a knowledge of the anatomy of the secreting tubes, and of the bloodvessels, the dissector will require a microscope, and good fine injec- tions of the kidney. Secretory tubules. The uriniferous tubes (tubuli uriniferi) occupy suc- cessively the cortical substance, and the Malpighian pyramids ; but they have a different arrangement in each part as below (fig. 164, a). In the Malpighian pyramid tubes are straight, and ascend from the apertures in the apex, bifurcating repeatedly, as far as the base, and form- ing a cone which resembles the stem and branches of a tree. At the wide end of the pyramid they are collected into bundles which reach nearly to the surface of the kidney, and become convoluted as they enter the cortex, but some unite in arches (Henle). Near the apex they measure 3^0^^^ ^^ an inch across, but the last subdivisions are only half that size, or ^Joth of an inch. Descending between the straight tubes are the small "' looped tubes" of Henle (fig. } 64, g). These run down from the cortical substance nearly to the apex of the pyramid, where they turn upwards, forming loops with the convexity down, and ascend to open into the straight tubes : their size is about a third of the others. In the cortical substance the tubes are more numerous and very convo- luted (fig. 165) ; they have an average width of g^o^^^ of an inch, and are surrounded by a capillary plexus of bloodvessels (fig. 166, a). At the one end (farther) each tube is dilated into the Malpighian corpuscle {b) ; and at the other it passes into a straight tube or joins an " arch" at the base of the pyramid. The '' looped tube&" of Henle (fig. 164) have the same arranfjement as the larger tubuli uriniferi in the cortical substance. The wall of the convoluted tubes consists of a thin basement membrane, and is lined by a thick, nucleated, and granular epithelium. Malpighian corpuscles (fig. 166, a). These small bodies are connected with the free ends of the convoluted tubes, one to each : and are arninged in double rows in the cortical substance between the pyramids, one row being on each side of an interpyramidal branch of artery, from which they receive tn'igs ; each measures about ji^yth of an inch, and consists of an incasing capsule with an inclosed tuft of bloodvessels (glomerulus). The capsule (b) is the dilated end of the convoluted tube, and is per- forated at tlie extremity by two small bloodvessels. Its wall consists of a thin basement membrane, and is lined by a transparent laminar epithe- lium. The glomerulus (fig. 166, b) is formed by the intercommunications of two vessels piercing the capsule, and is clothed with epithelium. One 476 DISSECTION OF THE ABDOMEN of the two, the afferent vessel (rf), is an offset of the renal artery, and divides into convoluted loops of the fineness of capillaries, which form the exterior of the tuft. The other, the efferent vessel (/), begins in the interior of tlie tuft by the union of the loops on the outer surface ; and Fig. 164. Fig 165, Plan of the Arrangement of the Urini- FERAL Tubes. a. Tube at its ending in the pyramid. h. Divisions of the same tube in the pyra- mid. d. Arches of Heule. c. Twisted tubes joining the "arches." g. Looped tube of Henle, with Its convo- luted part,/, and Malpighian corpuscle, e, in the cortical substance. Plan of Contorted Urine Tcbes ending in Malpiohian Corpuscles, which are con- nected with the small arteries {d). a. Urine tube. h. Malpighian corpuscles. c. Interpyramidal branch of renal artery (Bowman). passing out is distributed in a close network of capillaries (^) on the con- voluted urine tubes ; and in one with elongated meshes on the straighter tubes near the pyramids. The office of the glomerulus is to secrete the watery part of the urine. Bloodvessels. The artery and vein distributed to the kidney are very large in proportion to the size of the orsan they nourish. Renal artery. As the artery enters the kidney it divides into four or five branches, which are invested by slieaths of the fibrous capsule, and reach the bases of the pyramids of Malpiglii, where they form arches. From those arches arise small interpyramidal branches, which ascend towards the surface, and furnish the afferent twigs to the Malpighian bodies, whose arrangement has been referred to. Otlier offsets are sup- plied to the capsule and matrix of the kidney ; the former anastomose with the subperitoneal branches of the lumbar arteries. Straight vessels descend amongst the tubes in the pyramids of Malpighi, and some form loops like the tubes of Henle. Renal vein. This vein begins in the capillary plexuses on the convo- luted urine tubes; and its small branches, receiving twigs from the matrix BLOODVESSELS OF KIDNEY 477 and the fibrous coat, unite into larger veins, which anastomose freely around the bases of the pyramids of Malpighi. At this spot they are joined by offsets from capillary plexuses in the pyramids ; and the larger trunks then accompany the arteries to the sinus of the kidney. Finally all are united into one trunk, which opens into the vena cava. Fig. 166. a. Urine tube. b. End-dilatation. c. laterpyramidal artery. d. Afferent brancli. e. Glomerulus. /. Efferent vessel. g. Ple.xus of capillaries around the urine tube. h. Radicles of the veins. , e. Glomerulus. d. Afferent, and /. Efferent vessel of the glomerulus (Bowman). Plan of the Vessels connected with the Urine Tubes. Nerves. The ramifications of the sympathetic nerve may be traced to the smaller branches of the artery. The ahsorhents are superficial and deep : — The deep absorbents are sup- posed to begin in a plexus between the urine tubes. Both unite at the hilum of the kidney, and join the lumbar glands. The URETER is the tube by which the fluid secreted in the kidney is conveyed to the bladder. Between its origin and termination the canal measures from sixteen to eighteen inches in length. Its size corresponds commonly with that of a large quill. Near the kidney it is dilated into a funnel-shaped part, named pelvis ; and near the bladder it is again some- what enlarged, though the lower aperture by which it terminates is the narrowest part of the tube. Its relative anatomy must be studied after- wards, when the body is in a suitable position. In its course from the one viscus to the other, the ureter is close beneath the peritoneum, and is directed obliquely downwards and inwards along the posterior wall of the abdomen as far as the pelvis; here it changes its direction, and becomes almost horizontal. At first the ureter is placed over the psoas, inclining on the right side towards the inferior vena cava; and about the middle of the muscle it is crossed by the spermatic vessels. Lower down it lies over the common or the external iliac artery, being beneath the sigmoid flexure on the left side, and the end of the ileum on the right side. Lastly, it lies below the level of the obliterated hypo- gastric artery. Sometimes the ureter is divided into two for a certain distance. Part in the kidney (fig. 163, h). Near the kidney the ureter is dilated into a pouch called pelvis ; and it begins by a set of cup-shaped tubes, named calices or infundibula, which vary in number from seven to thir- teen. Each cup-shaped process embraces the rounded end of a pyramidal mass, and receives the urine from the apertures in that projection ; some- times a calyx surrounds two or more masses. The several calices are 478 DISSECTION OF THE ABDOMEN. united together to form two or three larger tubes ; and these are finally blended in the ureter. Structure. Besides an external fibrous layer, the ureter possesses a muscular and a mucous coat. The muscular covering is composed of an external or longitudinal, and of an internal or circular stratum. Tlie mucous coat is thrown into longitudinal folds during the contracted state of the ureter. Its epithelium consists of layers of cells of different shapes ; thus, at the free surface they are squarish, at the attached sur- face rounded, whilst in the intermediate strata they are cylindrical (Kol- liker). The calices resemble the rest of the duct in having a fibrous, a muscu- lar, and a mucous coat. Around the base of the pyramid the calyx is continuous with the enveloping tunic of the kidney; and at the apex the mucous lining is prolonged into the uriniferal tubes through the small openings. Vessels. The arteries are numerous but small, and are furnished by the renal, spermatic, internal iliac, and inferior vesical. The veins cor- respond with the arteries. The lymphatics are received into those of the kidney. THE SUPRARENAL BODY. This small body, whose use is unknown, has received its name from its position to the kidney. Its vessels and nerves are numerous, but it is not provided with any excretory duct. One on each side, it is situate on the upper extremity and fore part of the kidney ; and without care it may be removed with the surrounding fat, which it resembles. Its color is a brownish-yellow. It is like a cocked hat in form, with the upper part convex, and the base or lower part hollowed, where it touches the kidney. In the adult it measures about one inch and a half in depth, and rather less in width ; and its weight is between one and two drachms, but the left is commonly larger than the right. Areolar tissue attaches the suprarenal body to the kidney ; and large vessels and nerves retain it in place. The connections with the surround- ing parts are the same as those of the upper end of the kidney. Tlius it rests on the diaphragm on both sides ; whilst above the right is the liver, and above the left the pancreas and the spleen. On the inner side of the right capsule is the vena cava, with part of the solar plexus ; and internal to the left is the aorta, with the same plexus of nerves. Structure (fig. 167). A perpendicular section shows the suprarenal body to be formed of a firm or external (cortical) part, and of an internal (medullary) soft and dark material. With the microscope this body may be seen to consist of cells, which are lodged in spaces formed by a stroma of areolar tissue, with vessels and nerves. The whole is surrounded by a \.\\m Jihrous capsule (a), which sends pro- cesses into the interior, and along the bloodvessels. The cortical part, yellowish in color and striated, forms about two- thirds of the thickness of the whole body. Its stroma of areolar tissue (a) forms a thin surface layer, and is connected internally with processes or septa, whicii are so arranged as to build up spaces elongated from without inwards, and arranged vertically around the centre ; but near the surface CHARACTERS OF TESTIS, 479 Fig. 167. there are smaller oval spaces, some of them crossing the deeper and larger. The spaces or loculi (b) are filled by columnar masses of cells, but slight force readily removes these from their containing hollows. The central or medullary portion (c) is rather red in color, or it may be dark brown or black from the presence of blood. About half as thick as the cortical part, it possesses internally small round or oval spaces, on a section, which are vein trunks cut across. The areolar tissue of its stroma is very fine, and forms a network with small but regular meshes ; and the medullary is separated generally from the cortical portion by a layer of areolar tissue. Cells fill the meshes. Cells. The cells filling the loculi of the stroma in the cortex are nucleated with oil globules and fine granules ; and being packed in masses, they take on a polygonal form : they measure about the jT^^j^th of an inch. In the medullary portion the cells resemble those of the cortex, except that they do not contain oil particles ; and they are rather larger and more granular, measuring about xoVu^^ of an inch. Bloodvessels. Numerous arteries are furnished to the suprarenal body from the diaphragmatic and renal vessels, and from the aorta. In the interior the arteries ramify in the cortex along the septa between the cell masses ; and frequently anasto- mosing together, end in a fine capillary network, with elongated meshes, around the loculi. In the medullary part the fine arteries are distributed through the stroma. The veins originate in capillary plexuses ; and the several radiclee in large branches Vertical StcrIo^ of the Suprarenal Body. a. Surface layer of stroma. b. Cells in the cortex. c. Medullary portion. d. Spaces in the medullary part (Harley). which pass through the centre of the medullary part, are collected finally into one trunk ; this opens on the right side into the vena cava, and on the left into the renal vein. Other smaller veins pass out through the cortex to the renal vein and the vena cava. Nerves. The nerves are very numerous and large, and pass inwards along the septa of the cortical part : branching, they extend between the cortical and medullary parts in the layer of areolar tissue, and in the me- dullary substance they form a network in the are(jlar structure, but their ending is unknown. Lymphatics are superficial and deep, and both join those of the kidney ; the arrangement of the deep is undetermined. THE TESTES. The testes are the glandular organs for the secretion of the semen. Each is suspended in the scrotum by the spermatic cord and its coverings (p. 418), but the left is usually lower than the right; and each is pro- vided with an excretory duct named vas deferens. A serous sac partly surrounds each organ. Dissection. For the purpose of examining the serous covering of the testicle (tunica vaginalis), make a small aperture into it at the upper part, and inflate it. The sac and the spermatic cord are then to be cleaned ; 480 DISSECTION OF THE ABDOMEN. and the vessels of the latter are to be followed to their entrance into the testicle. The tunica vaginalis (fig. 168, d) is a serous bag, which is continuous in the foetus with the peritoneal lining ot the abdomen, but becomes subse- quently a distinct sac through the obliteration of the part connecting tlie two. It invests the testicle after the manner of other serous membranes : for the testicle is placed behind it, so as to be partly enveloped by it. The sac, however, is larger than is necessary for covering Fig. 168. the testicle, and projects some distance above it. Like other serous membranes, it has an external rouo;h, and an internal secerning smooth surface and like them it has a visceral and a parietal part. To examine its disposition tiie sac should be opened. The visceral layer (tunica vaginalis testis) covers the testicle, except posteriorly where the vessels lie. On the outer side it extends farther back than on the inner, and forms a pouch be- tween the testis and the arched body (epididymis) on this aspect of the organ. The parietal part of the sac (tunic, vagin. scroti) is more extensive than the piece covering the testicle, and lines the contiguous layer of the scrotum. Form and position of the testis (fig. 168). The testicle is oval in shape, with a smooth sur- face, and is flattened on tiie sides. The ante- rior, which is flattened, is pierced by the sperma- tic vessels and nerves. Stretching like an arcii along the outer part is the epididymis {b). At- tached to the upper end of the testis is a small body (c) two or three lines in length (corpus Morgagni), which is the remains of the upper end of the fwjtal duct of MuUer ; and occasionally other smaller projections of the tunica vaginalis are connected with the top of the epididymis. The testis is suspended obliquely, so tiiat the upper part is directed forwards and somewhat outwards, and the lower end backwards and rather inwards. Size and weight. The length of the testis is an inch and a half or two inches ; from before backwards it measures rather more tlian an inch, and from side to side rather less tlian an inch. Its weight nearly an ounce, and the left is frequently larger than the other. Structure. The substance of the testicle is composed of minute se- cerning tubes, around whicli the bloodvessels are disposed in plexuses. Surrounding and supporting the delicate seminiferal tubes is a dense covering — the tunica albuginea. Its excretory or efferent duct is named, vas deferens, Dissection. With the view of examining the investing fibrous coat, let the testis be placed on its outer side, viz., that on which the epididymis The Testis with the Tunica Vaginalis laid open. a. Testicle. b. Head of the epididymis. c. Corpus Morgagni. d. Parietal part of the tunica vaginalis. c. Vessels of the spermatic cord /. Vas deferens. STRUCTURE OF THE TESTIS. 481 lies, and let it be fixed firmly in that position with pins. The fibrous coat is to be cut through along the anterior part, and thrown backwards as far as the entrance of tlie bloodvessels. Whilst raising this membrane a number of fine bands will be seen traversing the substance of the testicle, and a short septal piece (mediastinum) may be perceived at the back of the viscus, where the .vessels enter ; but it will be expedient to remove part of the mass of tubes in the interior, to bring more fully into view the media- stinum, and to trace back some of the finer septa to it. The tunica albuginea^ or the fibrous coat of the testicle, is of a bluish- white color, and resembles in appearance the sclerotic coat of the eyeball. This membrane protects the secreting part of the testicle, and maintains the shape of the organ by its dense and unyielding structure: it also sends inwards processes to support and separate the seminal tubes. These seve- ral offsets of the membrane appear in the dissection ; and one of them at the back of the testicle, which is larger than the rest, is the mediastinum. The mediastinum testis (fig. 169, d) (corpus Highmorianum) projects into the gland for a third of an inch with the bloodvessels. It is situate at the back of the testis, extending from the upper nearly to the lower part, and is rather larger and deeper above than below. It is formed of two pieces, which are united anteriorly at an acute angle. To its front and sides the finer septal processes are connected ; and in its interior are con- tained the bloodvessels behind, and a network of seminal ducts in front (rete testis). Of thiijiner processes of the tunica albuginea (fig. 169, b) which enter the testis, there are two kinds. One set round and cord-like, but of diffe- rent lengths, is attached posteriorly to the mediastinum, and serves to maintain the shape of the testis. The other set forms delicate membranous septa, which divide the mass of seminal tubes into lobes, and join the mediastinum, like the rest. Within the tunica albuginea is a thin vascular layer, tunica vasculosa (Sir A. Cooper), which lines the fibrous coat, covering the different septa in the interior of the gland. It is formed of the ramifications of the blood- vessels, united by areolar tissue, like the pia mater of the brain ; in it the arteries are subdivided before they are distributed on the secerning tubes, and the small veins are collected into larger trunks. Form and length of the seminal tubes (tubuli seminiferi). The secern- ing or seminal tubes are very convoluted, and are but slightly held together by fine areolar tissue and surrounding bloo:lvesseIs, so that they may be readily drawn out of the testis for some distance : their length is said by Lauth to be two feet and a quarter. Ending^ size, and structure. Within the lobes of the testis some tube-? end in distinct closed extremities; but the rest communicate, forming loops or arches. The diameter of the tubules varies from ijj^th to yjijtli of an inch. The wall of the tubule is formed of a thin translucent mem- brane, but it has considerable strength. Lining the interior in the child is a nucleated granular epithelium, with polygonal cells; but in the adult the tube is filled by cells in different stages of development of the sper- matic corpuscles. On the exterior is a plexus of bloodvessels. Names from, the arrangement of the tubes. To different parts of the seminal tubes, the following names have been applied. AVhere the tubules are collected into masses, they form the lobes of the testis. As they enter the fibrous mediastinum they become straight, and are named tubuli recti. Communicating in the mediastinum, they produce the rete testis. And, 31 482 DISSECTION OF THE ABDOMEN. Ustly, as they leave the upper part of the gland they are convoluted, and are called coni vasculosi, or vasa efferentia. The lohes of the testis (fig. 109, o.) are formed by bundles of the semi- niferal tubes, and are situate in tiie intervals between the processes of the a. Lobes of the testis. 6. Septa betweea the lobes. c. Tubuli recti. d. Mediastinum testis. e. Rete testis. /. Vasa efferentia. g. Globus major. h. Body, and i, globus minor of the epididymis. li. Vas deferens. I. Vas aberrans. n. Rete testis, cut. o. Finer septa. p. Epididymis, cut across. r. Mediastinum, cut across. Vertical and Horizontal Sections of the Testis to show the arrangement op the Srminal Tubes, and Septa. tunica albuginea : their nunnber is differently stated : — according to one authority (Berres) they are 250; but according to another (Krause) 400 or more. They are conical in form, with the base of each at the circum- ference, and the apex at the mediastinum testis; and those in the centre of the testicle are the largest. Each is made up of one, two, or more tortuous seminal tubules ; and the minute tubes in one lobe are united wdth those in the neighboring lobes. Towards the apex of each lobe the tubules become less bent, and are united together; and the tubuli of the several lobes are further joined at the same spot into larger canals — the tubuli recti. TubuH recti (fig. 169, c). The seminal tubes unite together, becoming larger (^V^h of an inch) and straighter in direction, and are named tubuli recti or vasa recta: they are about twenty in number, and piercing the fibrous mediastinum enter into the rete testis. Rete testis (fig. 169, e). In the mediastinum the seminal tubes have very thin walls, and are situate in the anterior part, in front of the blood- vessels; they communicate freely so as to form a network. Vasa efferentia (fig. 169,/). About twelve or twenty seminal tubes issue from the top of the rete, and leave the upper part of the testicle as the vasa efferentia: these are larger than the tubes with which they are continuous, and end in the common excretory duct.. Though straight at first they soon become convoluted, and have been named coni vasculosi. In the natural state they are about half an inch in length, but when un- ravelled they measure six inches; and they join the excretory duct at in- tervals of about three inches. They have a muscular coat of longitudinal and circular fibres; and the epithelium of the mucous lining is columnar and ciliated. The EXCRETORY DUCT rcceivcs the vasa efferentia from the upper part of the gland, and extends thence to the urethra. Its first part, which is in contact with the testis, is very flexuous, and forms the epididymis: but the remainder is straight, and is named vas deferens. DUCT OF TESTIS. 483 The epididymis (fig. 169, h) extends in the form of an arch along the outer side of the testis, from the upper to the lower end, and receives its name from its situation. Opposite the upper part of tlie testicle it pre- sents an enlarged portion or head, the globus major {^g) ; and at the lower end of that organ it becomes more pointed or tail-like — globus minor (i), before ending in the vas deferens. The intervening narrow part of the epididymis is called the body (h). Its head is attached to the testis by the vasa efferentia; and its lower part is fixed to the tunica albuginea by fibrous tissue, and by the reflection of the tunica vaginalis. The epididymis is formed of a single tube, bent in a zigzag way, whose coils are united into a solid mass by fibrous tissue. After the removal of the serous membrane and some fibrous tissue this part of the tube may be uncoiled; it will then measure twenty feet in length. The diameter of its canal is about y^th of an inch, though there is a slight diminution in size towards the globus minor, but it is increased finally in the vas deferens. The vas deferens (fig. 169, k) begins opposite tlie lower end of the tes- tis, at the termination of the globus minor of the epididymis. At first this part of the excretory duct is slightly wavy, but afterwards it becomes for the most part a firm round tube : near its termination it is enlarged again and sacculated, but this condition will be referred to with the viscera of the pelvis. In its course to the urethra it ascends on the inner side of the testicle, and along the bloodvessels of the spermatic cord with w^iich it enters the internal abdominal ring; it is then directed over the side of the bladder, and through the prostate to open into the urethra. The length of this part of the excretory duct is about two feet, and the width of its canal about ^^^th of an inch. Opening sometimes into the vas deferens, at the angle of union with the epididymis, is a small narrow crecal appendage, the vas aberrans of Haller (fig. 169, /). It is convoluted, and projects upwards for one or two inches amongst the vessels of the cord. Like the epididymis, it is longer when it is uncoiled : its capacity is greatest at the free end. Its use is unknown. Structure, The excretory duct of the testis has a thick muscular coat, which is covered externally by fibrous tissue, and lined internally by mu- cous membrane. To the feel the duct is firm and wiry, like whip-cord. On a section its w^all is dense and of a rather yellow color, but it is thinnest at the head of the epididymis. The muscular coat is composed of longitudinal and circular fibres ar- ranged in strata. Both externally and internally is a longitudinal layer, the latter being very thin ; and between them is the layer of circular fibres. The mucous membrane is marked by longitudinal folds in the straight part of the canal, and by irregular ridges in the sacculated portion. A columnar epithelium, though not ciliated, covers the inner surface ; but in the epididymis it is ciliated (Becker). Organ of Giraldes} In the spermatic cord of the foetus and child, close above the epididymis, is a small whitish granular-looking body (" Corps Innomine," Giraldes), about half an inch long — the remains of the low^er part of the Wolffian body of the embryo. With slight magnifying power its com{)onent white granules are resolved into small vesicles, and convo- luted tubes of varying shape, filled with a clear thick fluid; their wall 1 Sur uii Organe place dans le Cordon Spermatique, et dont I'existence n'a pas ete signalee par les Anatomistes. Par F. Giraldes. Proceedings of the Royal Society for May, 1858. 48-4 DISSECTION OF THE ABDOMEN. consists of a thin membrane, lined by fluttened epithelium, with plexuses of' bloodvessels ramifying on the exterior. Bloodvessels and nerves of the testicle. The branches of the spermatic artery supply offsets to the epididymis, and pierce the back of the testicle to enter the posterior part of the mediastinum. The vessels are finely divided in the vascular structure lining the interior of the tunica albugi- nea; and offsets are continued on the fine septa to the seminal tubules, on which they are distributed in capillary plexuses. The spermatic vein begins by radicles in the plexuses around the seminal tubes, and issues from the gland at the posterior part, being there joined by veins from the epididymis. As it ascends along the cord its branches form the spermatic plexus ; it joins the vena cava on the right side, and the renal vein on the left (p. 492). The arrangement of the lymphatics in the testicle is unknown ; external to that body they ascend on the bloodvessels, and join the lumbar glands. The nerves are derived from the sympathetic, and accompany the arte- ries to the testis : their ending has not been seen. Vessels of the vas deferens. A special artery is furnished to the excre- tory duct from the upper or lower vesicle, and reaches as far as the testis, where it anastomoses with the spermatic artery. Veins from the epididy- mis enter the spermatic vein. The nerves are derived from the hypogastric plexus. Section V. DIAPHRAGM WITH AORTA AND VENA CAVA. Directions. After the body is replaced in its former position on the Back, the student should ])repare first the diaphragm, next the large ves- sels and their branches, and then the deep muscles of the abdomen. Dissection. For the dissection of the diaphragm it will be necessary to remove the peritoneum, defining especially tiie central tendinous part, and the fleshy processes or pillars which are fixed to the lumbar vertebrje. Whilst cleaning the muscle the student should be careful of the vessels and nerves on the surface, and of others in and near the pillars. On the right side two aponeurotic bands or arches, near the spine, which give attachment to the muscular fibres, should be dissected : one curves over the internal muscle (psoas); the other extends over the exter- nal muscle (quadratus), and will be made more evident by separating the fascia covering the quadratus from it. The DIAPHRAGM (fig. 168, ^) forms the vaulted movable partition be- tween the thorax and the abdomen. It is fleshy externally, where it is attached to the surrounding ribs and the spinal column, and has its tendon in the centre. The origin of the muscle is at the circumference, and is similar on each side of the middle line. Thus, it is connected by fleshy sli])S with the |)os- terior part of the xiphoid cartilage, and the inner surface of the six lower ribs; with two aponeurotic arches between the last rib and the spinal column — one being placed over the quadratus lumborum, and the other over the psoas muscle ; and, lastly, it is connected with the lumbar verte- brae by a thick muscular part or pillar. From this extensive origin the DIAPHRAGM AND ITS ACTION. 485 fibres are directed inwards, with different degrees of obliquity and length, to the central tendon, but some have a peculiar disposition in the pillars which will be afterwards noted. The abdominal surface is concave, and is covered for the most part by the peritoneum. In contact with it on the right side are the liver and the kidney; and on tlie opposite side, the stomach, the spleen, and the left kidney: in contact also with the pillars is the pancreas, together with the solar plexus and the semilunar ganglia. The thoracic surface is covered by the pleura of each side and the pericardium, and is convex towards the thorax (p. 343). At the circumference of the midritf the fleshy processes of origin alternate with like parts of the transversalis muscle; but a slight interval separates the slips to the xiphoid cartilage and seventh rib, and a second space exists sometimes between the fibres from the last rib and the arch over the quadratus lumborum muscle. In it are certain apertures for the transmission of parts from the tiiorax to the abdomen. The muscle is convex towards the chest, and concave to the abdomen. Its arch reaches higher on the right than the left side (p. 30G), and is con- Yicr. 170. A. Diaphragm. B. Psoas raaguus. c. Quadratus lumborum. a. Left piece of the teudon of the diaphragm ; 6, middle; and c, right piece. Ua'deb Surface of the Diaphraom. d. Left, and e, right cms. /. Inner, and g, outer arched ligament. A- Opening for vena cava ; i, for oesophagus, t, for aorta, y, for sympathetic nerves. stantly varying during life in respiration. In forced expiration the muscle ascends, and reaches as high as the upper border of the right fourth rib at the sternum, and the upper edge of the fiftii rib on the left side, close to the sternum. In forced inspiration it descends, and its slope would be represented by a line drawn from the middle of the ensiform cartilage to the eleventh rib. Action. As the muscle moves up and down during respiration, it is depressed by the contraction of the fleshy fibres which are attached to the ribs and spine, and is raised during their relaxation. 486 DISSECTION OF THE ABDOMEN. When the diaphragm descends it changes its shape. The central tendon, -wliich moves but sliglitly, remains the higliest part of the arch, whilst the sides which contract freely are sloped from the tendon to the wall of the thorax. During the ascent the midriff retains nearly the same form as in a state of rest, for the tendon is the lowest part of the arch, and the bulges on the sides reach rather higher. With the movement of tlie diaphragm the size of the cavities of the abdomen and thorax will be altered. In inspiration the thorax is enlarged, and the abdomen diminished ; and the viscera in the upper part of the latter cavity, viz., liver, stomach, and spleen, are partly moved from be- neath the ribs. In expiration tlie cavity of the thorax is lessened, and that of the abdomen is restored to its former size ; and the displaced viscera return to their usual place. By the contraction of tlie fibres the aperture for the oesophagus will be rendered smaller, and that tube may be com- pressed ; but the other openings for tlie vena cava and aorta do not ex- perience change. Preparatory to the making of a great muscular effort, the midriff con- tracts, and descends for the purpose of permitting a full quantity of air to enter the thorax. Till the effort is over tlie diaphragm remains in a de- pressed position. ' Its action is commonly involuntary, but the movement can be controlled by the will at any stage. Parts of the diaphragm. The following named parts, which have been noticed shortly in describing the muscle, are now to be referred to more fully, viz., the central tendon, the pillars, the arches, and the apertures. The central tendon (cordiform tendon) occupies the middle of the dia- phragm (fig. 170), and is surrounded by muscular fibres; the large vena cava pierces it. It is of a pearly white color, and its tendinous fibres cross in different directions. In form it resembles a trefoil leaf: of its three segments the right (c) is the largest, and the left {a) the smallest. The pillars (crura) are two large muscular and tendinous processes {d and e), one on each side of the abdominal aorta. They are pointed and tendinous below, where they are attached to the upper lumbar verte- brae, but large and fleshy above ; and between them is a tendinous arch over the aorta. In each pillar the fleshy fibres pass upwards and forwards, diverging from each other : the greater number join the central tendon without in- termixing, but the inner fibres of the two crura cross one another in the following manner : — Those of the right (e) ascend by the side of the aorta, and pass to the left of the middle line decussating with the fibres of the opposite crus between that vessel and the opening of the ojsophagus. The fibres of the other crus {d) may be traced in the same way, to form the right half of the oesophagean opening. In the decussation the fasciculus of fibres from the right crus is generally larger than that from the left, and is commonly anterior to it. The pillars differ somewhat on opposite sides. The right {e) is the larger of the two, and is fixed by tendinous processes to the bodies of the first three lumbar vertebra?, and their intervertebral substance, reaching to the disk between the third and fourth vertebrae. The left pillar {d) (sometimes absent) is situated more on the side of the spine, is partly con- cealed by the aorta, and does not reach so far as the right by the depth of a vertebra, or of an intervertebral substance. The arches (ligamenta arcuata) are two fibrous bands on each side over SPECIAL PARTS OF DIAPHRAGM. 487 the quadratus lumborum and psoas muscles, which give origin to fleshy fibres. The arch over the psoas (lig. arcuat. internum/) is the strongest, and is connected by the one end to the tendinous part oP the pillar of the dia- phragm, and by the other to the transverse process of the first or the second lumbar vertebra. The arch over the quadratus lumborum (lig. arcuat. externum ^^) is only a thickened part of the fascia covering that muscle, and extends from the same transverse process (first or second lumbar) to tlie last rib. Apertures. There are three large openings for the aorta, the vena cava, and the oesophagus ; with some smaller fissures for nerves and vessels. The opening for the aorta (/») is rather behind, than in the diaphragm, for it is situate between the pillars of the muscle and the spinal column : it transmits the aorta, the thoracic duct, and tlie vena azygos. The opening for the oesophagus and tlie pneumo-gastric nerves (/) is rather above and to the left of the aortic aperture ; it is placed in the muscular part of the diaphragm, and is bounded by the fibres of the pillars as above explained. The opening for the vena cava (/^) (foramen quadratum) is situate in the right division of the central tendon ; and its margins are attached to the vein by tendinous fibres, except at the inner part. There is a fissure (/) in each pillar for the three splanchnic nerves ; and through that in the left crus passes also the small azygos vein. Dissection. After the diaphragm has been learnt, the ribs that support it on each side may be cut through, and the pieces of the ribs with tlie fore part of the diaphragm may be taken away, to make easier the dissec- tion of the deeper vessels and muscles. But the posterior part of the dia- phragm with its pillars and arches should be left ; and the vessels ramify- ing on it should be followed back to their origin. The large vessels of the abdomen, viz., the aorta and the vena cava, are to be cleaned by removing the fat, the remains of the sympathetic, and the lymphatic glands ; and their branches are to be followed to the dia- phragm, to the kidney and suprarenal body, and to the testicle. In like manner the large iliac branches of the aorta and cava are to be laid bare as far as Poupart's ligament. The ureter and the spermatic vessels are to be cleaned as they cross the iliac artery to the limb ; and on the iliac trunk near the thigh, branches of a small nerve (genito-crural) are to be sought. The muscles are to be laid bare on the right side, but on the left side the fascia covering them is to be shown ; and the fat is to be cleared away from about the kidney. The psoas muscle, the most internal of all, lies on the side of the spine, with the small psoas superficial to it occasionally. On its surface, and in the fat external to it, the following branches of the lumbar plexus will be found : The genito-crural nerve lies on the front. Four other nerves issue at the outer border — the ilio-hypogastric and ilio-inguinal near the top, the external cutaneous about the centre, and the large anterior crural at tiie lower part. Along the inner border of the psoas the gangliated cord of the 6ym|)athetic is to be sought, along with a chain of lumbar lymphatic glands ; and somewhat below the pelvic part of the muscle the obturator nerve may be recognized. External to the psoas is the quadratus lum- borum, and crossing it near the last rib is the last dorsal nerve, with an 488 DISSECTION OF THE ABDOMEN Fig. 171. Deep view of the Muscles, "V E8SELS , AN (Illus tration 3 Of Muscles and viscera : A. Diaphragm with B.int ternal arched ligame ernal nt. and c, e.K- D. End of the oesophagus cut. K. Small psoas. P. Large psoas. G. QuadratQS lumborum. H. Iliacus. I. Kidney. J. Recturn. K. Bladder. Vessels : a. Diaphragmatic artf^ry b. Aorta. c. Renal. d 8p'»rmatic. e. Upper mesenteric, cut. /. Lower mesenteric. D Nerves op this Abdominal Cavitt. Dissections.) g Common iliac, and /(, external iliac artery. "k. Epigastric artery, cut ; by its side is the vas deferens, bonding into the pelvis. /. Circumflex iliac. in. Vena cava. n. Renal vein. ' 0. Right spermatic vein, 30, common iliac vein, and r, external iliac (this letter is put on the left artery instead of the v. 448) ; and the blood contained in those veins reaches the cava by the ven^e cava? hepaticiv?, after it has circulated through the liver. The spermatic vein (fig. 171, o) enters the abdomen by the internal abdominal ring, after forming the spermatic plexus in the cord (p. 484). At first there are two branches in the abdomen, which lie on the sides of the spermatic artery; but these soon join into one trunk. On the left side it opens into the renal vein at right angles, and a small valve exists sometimes over the aperture ; on the right side it enters the inferior cava below the renal vein. As the vein ascends to its destination, it receives ojje or more branches from the wall of the abdomen, and from the fat about the kidney. In the female this vein (ovarian) has the same ending as in the male, and it forms a plexus in the broad ligament of the uterus. Valves are absent from the vein and its branches, but occasionally there is one at its union with the renal. The renal or emulgent vein (fig. 171, n) is of large size, and joins the vena cava at a right angle. It commences by many branches in the kid- ney; and the trunk resulting from their union is superficial to the renal artery. The right is the shortest, and joins the cava higher up usually than the other. The left vein crosses the aorta close to the origin of the superior mesenteric artery : it receives separate branches from the left spermatic and suprarenal veins. The suprarenal vein is of considerable size when it is compared with the body from which it comes. I'he right opens into the cava, and the left into the renal vein. The hepatic veins enter the vena cava where it is in contact with the liver. These veins are described in the dissection of the liver (p. 468). The Idmhar veins correspond in number and course with the arteries of the same name : they will be dissected after. The diaphragmatic veins (inferior), two with each artery, spring from the under surface of the diaphragm. They join the cava either as one trunk or two. DEEP MUSCLES OF THE ABDOMEN. The deep muscles in the interior of the abdomen are the psoas, iliacus, and quadratus lumborum. The PSOAS MAGNUS (fig. 171, '') reaches from the lumbar vertebra? to the femur, and is situate partly in the abdomen and partly in the thigh. PSOAS AND ILIACUS MUSCLES. 493 The muscle arises from the front of the transverse processes of the lumbar vertebrae; from the bodies and intervertebral disks of the last dorsal and all the lumbar vertebrae by five ileshy pieces — each piece being connected with the intervertebral substance and the borders of two con- tiguous vertebrae, and with tendinous bands over the bloodvessels opposite tlwi middle of tiie vertebrie. The fibres give rise to a roundish belly, which gradually diminishes towards Poujjart's ligament, and ends inte- riorly in a tendon on the outer aspect, which receives fibres of the iliacus, and passes beneath Poupart's ligament to be inserted into the small tro- chanter of the femur. The abdominal part of the muscle has the following connections: — In front are the internal arch of the diaphragm, the kidney with its vessels and duct, the spermatic vessels, and the genito-crural nerve, and, near Poupart's ligament, the ending of tlie external iliac artery. Posteriorly the muscle is in contact with the transverse processes, with part of the quadratus lumborum, and with tlie innominate bone. The outer border touches the quadratus and iliacus; and branches of the lumbar plexus issue from beneath it. Tlie inner border is partly con- nected to the vertebrt^, and is partly free along the margin of the pelvis: — along the attached part of this border lies the sympathetic nerve, with the cava on the right, and the aorta on the left side ; along the free or pelvic part are the external iliac artery and vein. Action. If the femur is free to move it is raised towards the belly; and as the flexion proceeds, the limb is rotated out by the attachment of the muscle to the trochanter minor. The psoas is always combined with the iliacus in flexion of the hip-joint. When the lower limbs are fixed the two muscles will draw down the lumbar part of the spine, and bend the hip-joints, as in stooping to the ground. One muscle under the same circumstances can incline the spine laterally. The PSOAS PARVUS (fig. 171, ^) is a small muscle with a long and flat tendon, which is placed on the front of the large psoas, but is rarely pre- sent. Its fibres ainse from the bodies of the last dorsal and first lumbar vertebras, with the intervening fibro-cartilage. Its tendon becomes broader interiorly, and is inserted into the ilio-pectineal eminence and the brim of the pelvis, joining the fascia over the iliacus muscle. Action. If the spine is immovable the two muscles will make tense the pelvic fascia. The pelvis being fixed they may assist in bending the lumbar part of the spinal column. The ILIACUS MUSCLE (fig. 171, ") occupies the iliac fossa on the inner aspect of the hip-bone, and is blended inferiorly with the psoas. It is triangular in form, and has a fleshy origin from the iliac fossa and the ilio-lumbar ligament, from the base of the sacrum, and from the capsule of the hip-joint in front. The fibres pass inwards to the tendon of the pvsoas, uniting with it even to its insertion into the femur, but some reach separately the femur near the small trochanter. Above Poupart's ligament the muscle is covered by the iliac fascia; but over the right iliacus is placed the ctccum, and over the left, the sigmoid flexure. Beneath it are the innominate bone and the capsule of the hip- joint; and between it and the grooved anterior margin of the bone, above the joint, is a bursa. The inner margin is in contact with the psoas and the anterior crural nerve. The connections of the united psoas and iliacus below Poupart's ligament are given with the dissection of the thigh. 494 DISSECTION OF THE ABDOMEN. Action. The iliacus flexes the hip-joint with the psoas when the femur is movable, and bends forwards the pelvis when the limb is fixed. In consequence of its union with the psoas, the two are described as the flexor ot the hip-joint by Tlieile. The QUADRATus LUMBORUM (fig. 171 ^) is a short thick muscle be- tween the crest of the hip-bone and the last rib. About two inches wide inferiorly, it arises from the ilio-vertebral ligament, and from the iliac crest of the hip-bone behind, and an incii outside that band. The fibres ascend to be inserted by distinct fleshy and tendinous slips into the apices of the transverse processes of the four upper, or all the lumbar vertebrse ; and into the body of the last dorsal vertebra, and the lower border of the last rib for a variable distance. This muscle is encased in a sheath derived from the fascia lumborum. Crossing the surface are branches of the lumbar plexus, together with the last dorsal nerve and its vessels. Beneath the quadratus is the mass of the erector spinae muscle. Action. Both muscles keep straight the spine (one muscle antagonizing the other) ; and by fixing the last rib they aid in the more complete con- traction of the diaj)hragm. One muscle will incline laterally the lumbar part of the spine to the same side, and depress the last rib. Fascia of the quadratus. Covering the surface of the quadratus is a thin membrane, which is derived from the hinder aponeurosis of the trans- versalis abdominis (fascia lumborum, p. 357) ; it passes in front of the quadratus to be fixed to the tips and borders of the lumbar transverse pro- cesses, to the ilio-lumbar ligament below, and to the last rib above. This fascia forms the thickened band called ligamentum arcuatum externum, to which the diaphragm is connected. Fascia of the iliacvs and psoas. A fascia covers the two flexor muscles of the hip-joint, and extends in different directions as far as their attach- ments. Over the iliacus muscles the membrane is thickest ; and a strong accession is received from the tendon of the small psoas. Its disposition at Poupart's ligament, and the part that it takes in the formation of the crural sheath, have been before explained (p. 428). Opposite the pelvis the membrane is inserted into the brim of that cavity for a short distance, and into the hip bone along the edge of the psoas. Opposite the spinal column it becomes thin, and is fixed on the one side to the lumbar vertebrae and the ligamentum arcuatum internum, but is blended on the other with the fascia on the quadratus. The fascia should be divided ov^per's glands in the male. Each is about as large as a small bean ; and its duct is directed forwards to open on the inner aspect of the nympha of the same side. Tlie duct resembles that of Cowper's gland in its structure (p. 398). THE UTERUS. The uterus or womb is formed chiefly of unstriated muscular fibres. Its office is to receive the ovum, and to retain for a fixed period the de- veloping foetus. This viscus in the virgin state is somewhat pear shaped, the body being flattened (fig. 187), and possesses inferiorly a rounded narrow part or neck. Before impregnation the uterus measures about three inches in length, two in breadth at the upper part, and an inch in greatest thickness. Its weight varies from an ounce to an ounce and a half. But after gestation its size and volume exceed always the measurements here given. The upper end is convex, and is covered by peritoneum : the term fundus is applied to the part of the organ above the attachment of the Fallopian tube (e). The loiver end is small and rounded, and in it is a transverse aperture of communication between the uterus and the vagina, named os uteri (os tincce) : its margins or lips (labia) are smootli, and anterior and posterior in situation, but the hinder one is the longest. Towards the lower part tiie uterus is constricted, and this diminished portion is called the neck (6) of the uterus (cervix uteri) ; it is surrounded by the vagina, and is covered by tiiis tube to a greater extent behind than in front. The neck is about lialf an inch in length, and gradually tapers towards the ex- tremity. The body (a) of the uterus is more convex posteriorly than anteriorly, and decreases in size down to the neck. It is covered on botii aspects by the peritoneum, except at the lower part in front (about half an inch), where it is connected to tlie bladder. To each side, which is straight, the parts contained in tlie broad fold of the peritoneum are attached (fig. 175): — viz., the Fallopian tube at the top (m) ; the round ligament (x), rather below and before it; and tiie ovary (l), and its ligament below and behind the others. Dissection. To examine the interior of the uterus, a cut is to be made along the anterior wall from the fundus to the os uteri ; and tiien some of the thick wall is to be removed on each side of the middle line to show the contained artery. 638 DISSECTION OF THE PELVIS. The tluckness of the uterine wall is greatest opposite the middle of the body. It is greater at the centre than at the angles of the fundus (fig. 187), the wall becoming thinner towards the attachment of the Fallopian tubes. Interior of the vterus (fig. 187). Within the uterus is a small space, which is divided artificially into two — that of the body, and that of the neck. The space occupying the body of the viscus (c) is triangular in form, and is larger than the other. Its base is at the fundus, where it is convex towards the cavity, and tlie angles are prolonged towards the Fallopian tubes. The apex is directed downwards, and joins the cavity in tiie cer- vix by a narrowed circular part, isthmus, which may be narrower than the opening of the uterus into the vagina. The space within the neck (ri) terminates inferiorly at the os uteri, and is continuous above with the space within the body. It is larger at the middle than at either end, being spindle-shaped, and is somewhat flattened Fig. 187. Interior of the Utercs, with a Posterior View of the Broad Ligament and the Uterine Appendages. a. Body, and 6, neck of the uterus. g. The fimbria attached to the ovary. c. Cavity of the body, and d, of the neck. h. Ovary, and i, ligament of the ovary. e. Fallopian tube, and /, its trumpet-shaped k. Parovarium. end. like the cavity of the body. Along both the anterior and the posterior wall is a longitudinal ridge ; and the other ridges {rugce) are directed ob- liquely from these on each side : this appearance has been named arbor vitce uterinus. In the intervals between the rugte are mucous follicles, which sometimes become distended with fluid, and give rise to rounded clear sacs. Structure. The dense wall of the uterus is composed of layers of unstriated muscular fibre, intermixed with areolar and elastic tissues, and large bloodvessels. On the exterior is the peritoneum ; and lining the interior is a thin mucous membrane. The muscular fibres can be demonstrated at the full period of gestation to form three strata in the wall of the uterus, viz., external, internal, and middle : — The external layer contains fibres which are mostly transverse ; but at the fundus and sides they are oblique, and are more marked than along I OVARTES AND FALLOPIAN TUBES. 539 the middle of the organ. At the sides the fibres converge towards the broad ligament ; some are inserted into the subperitoneal fibrous tissue ; and others are continued into the Fallopian tube, the round ligament, and the ligament of the. ovary. The internal fibres describe circles around the openings of the Fallopian tubes, and spread from these apertures till they meet at the middle line. At the neck of the uterus they are arranged in a transverse direction. The middle or intervening set of fibres are more indistinct than the others, and have a less determinate direction. The mucous lining of the uterus is continued into the vagina at one end, and into the Fallopian tubes at the other. In the body of the uterus it is of a reddish-white color, and is thin, smooth, and adherent, but without papillae. Like the mucous membrane of the intestine, it possesses tubular glands^ which may be either straight and simple, or twisted and branched ; they are lined by ciliated epithe- lium, and their minute apertures are scattered over the surface. In the cervix uteri, between the rugae, muaou^ follicles and glands are collected, and near the outer opening are papillae. The epithelial covering of the mucous membrane consists of a single layer of cells, which are columnar and ciliated throughout the cavity of the uterus. The bloodvessel s of the uterus are large and tortuous and occupy canals in the uterine substance, in which they communicate freely together. The arteries are furnished from the uterine and ovarian branches (p. 516). The veins correspond with the arteries : they are large in size, and form plexuses in the uterus. The nerves are derived from the sympathetic (p. 519), and are very small in proportion to the size of the uterus : in the cervix they are traced to the papilla?. Lymphatics. One set accompanies the uterine vessels to the glands on the iliac artery. Another set issues from the fundus, enters the broad ligament, and accompanies the ovarian artery to the glands on the aorta : the last are joined by lymphatics of the ovary and Fallopian tube. Bound ligame7it of the uterus (fig. 175, n). Tliis firm cord supports the uterus, and is contained partly in the broad ligament, and partly in the inguinal canal. It is about five inches in length, and is attached to the upper part of the uterus close below, and anterior to the Fallopian tube. A process of the peritoneum accompanies it in the inguinal canal, and remains pervious sometimes for a short distance. Tiie ligament is comjjosed of unstriated muscular fibres, derived from the uterus, together with vessels and areolar tissue. OVARIES AND FALLOPIAN TUBES. Ovary (fig. 187). The ovaries are two bodies, corresponding with the testes of the male. They are contained in the broad ligaments of tlie uterus, one in each. Each ovary is of an elongated form, and somewhat flattened from above down. It is of a whitish color, with either a smootii or a scarred surface. Its volume is variable ; but in the virgin state it is about one inch and a half in length, half that size in width, and a third of an inch in thickness. Its weight varies from one to two drachms. The ovary is placed at the back of the broad ligament, and is connected 540 DISSECTION OF THE PELVIS. Fig. 188. with tliat membrane by its anterior margin, where the vessels enter the stroma. Its outer end (^) is rounded and is connected with one of the fimbriie at the mouth of the Fallopian tube. The inner extremity is nar- rowed, and is attached to the side of the uterus by a fibrous cord (i) — the ligament of the ovary, below the level of the Fallopian tube and round ligament. Structure. The ovary consists of a stroma of areolar tissue containing small sacs named Graafian, and the whole is inclosed within a fibrous tunic. The peritoneum surrounds it except at the attached margin. The fibrous coat is adherent to the contained stroma. Along the at- tached margin of the ovary is a slit, by which the vessels and nerves enter. Sometimes a yellow spot (corpus luteum), or some cicatrices, may be seen in this covering. Stroma (fig. 188). The substance of the ovary is spongy, vascular, and fibrous. At the centre the fibres radiate from the hilum towards the circumference. But at the exterior is a granular material (cortical layer) which contains very many small cells, about ^^jythof an inch in size — the nascent Graafian vesicles. The Graafian vesicles or ovisacs (fig. 188) are round and transparent cells, scattered through the stroma of the ovary below the cortical layer. During the child-bearing period some are larger than the rest (a) ; and of this larger set ten to thirty, or more, may be counted at the same time ; these vary in size from a pin's head to a pea. The largest are situate at the circum- ference of the organ, and sometimes they may be seen projecting through the fibrous coat. Each consists of a transparent coat with a fluid inside. The coat of the vesicle named ovi-capsule (tunica fibrosa), is formed of fine areolar tissue, and is united to the stroma of the ovary by bloodvessels, which ramify in the wall. Lining it is a layer of nucleated granular cells — the membrana granulosa, whicli is thickened at one spot, and surrounds the ovum at the discus pro- ligerus (Von Baer), fixing it to the wall. Ths fluid in the interior is transparent and albuminous ; it contains the minute ovum, to"rether with molecular granules. When the Graafian vesicle is matured it bursts on the surface of the ovary, and the contained ovum escapes into the Fallo[)ian tube. After the shedding of the ovum the ruptured vesicle gives origin to a yellow substance, corpus lateum, which finally clianges into a cicatrix (&). Bloodvessels and nerves. The ovarian artery pierces the ovary at the anterior or attached border, and its branches run in zigzag lines through the stroma, to which and the Graafian vesicles they are distributed. The veins ])egin in the vesicles and the texture of the ovary, and after escaping from its substance, form a plexus {pam-piniform) within the fold of tlie broad ligament. The nerves are derived from the sympathetic on tiie ovarian and uterine vessels. Appendage to the ovary (fig. 187, k) (Parovarium, Organ of Rosen- OVARY DURING THE ChII.D-BEABINO Period laid open. a. Graaflau vesicles in diflfereat stages of growth. h. Plicated body remainiag after the escape of the ovum (Farre). BLADDER AND URETHRA IN FEMALE. 541 miiller). On holding up the broad ligament of the uterus to the light, a collection of small tortuous tubules will be seen between the ovary and the Fallopian tube. This is the remnant of the upper part of the Wolffian body of the foetus ; it is about one inch broad, with its base to the Fallo- pian tube, and apex to the attached part of the ovary. The small tubes are from twelve to twenty in number ; at the wider end they are joined more or less perfectly by a tube crossing the rest, which is prolonged sometimes a short way into the broad ligament. Each tube is a closed fibrous capsule with a clear fluid within, and with a lining of epithelium. Fallopian Tubes (fig. 187, e). Two in number, one on each side, they convey the ova from the ovaries to the uterus, and correspond in their office with the vasa deferentia in the male. Each is about four inches in length : cord-like at the inner end, where it is attached to the upper part of the uterus, it increases in size towards the outer end, and terminates in a wide extremity (/), like the mouth of a trumpet. This dilated end is fringed, and the pieces are called Jim bri'cR. When the fimbriated end is floated out in water, one of the processes (g) may be seen to be connected with the outer end of the ovary. In the centre of the fimbrise is a groove leading to the orifice of the Fallopian tube. On opening the tube with care, the size of the contained space, and its small aperture into the uterus can be observed. Its canal varies in size at different spots: the narrowest part is at the orifice into the uterus (ostium uterinum), where it scarcely gives passage to a fine bristle; towards the outer end it increases a little, but it is rather diminished in diameter at the outer aperture (ostium abdominale). Structure. This excretory tube has the same structure as the uterus with which it is connected, viz., a muscular layer covered externally by peritoneum, and lined by mucous membrane. The muscular coat is formed of an external or longitudinal, and an in- ternal or circular layer ; both these are continuous with similar strata in the wall of the uterus. The mucous membraiie forms some longitudinal folds, particularly at the outer end. At the inner extremity of the canal it is continued into the mucous lining of tlie uterus, but at the outer end it joins the peritoneum. A columnar and ciliated epithelium covers tlie surface, as in the uterus, and is said by Henle to be detected on the outer surface of the fimbriie. The bloodvessels and nerves are furnished from those supplied to the ovary and uterus. THE BLADDER, URETHRA, AND RECTUM. Bladder. The peculiarities in the form and size of the female bladder have been detailed in the description of the connections of the viscera of the female pelvis (p. 513). For a notice of its structure, the anatomy of the male bladder is to be referred to (p. 524). Dissection. To prepare the bladder, distend it with air, and remove the peritoneal covering and the loose tissue from the muscular fibres. After the external anatomy of the bladder, and urethra has been learnt, they are to be slit open along the upper part. Urethra. The length and the connections of the excretory tube are given in page 512. The average diameter of the uretlira is rather more than a quarter of an inch, and the canal is enlarged and funnel-shaped towards the neck of the 642 DISSECTION OF THE PELVIS.. bladder ; near the external aperture is a hollow in the floor. In conse- quence of not being surrounded by resistant structures, the female urethra is much more dilatable than the corresponding passage in the male. Structure. Like the urethra of the male, it consists of a mucous coat, which is enveloped by a plexus of bloodvessels, and by muscular fibre. The muscular layer extends the whole length of the urethra. Its fibres are circular, corresponding with the prostatic enlargement in the other sex, and continuous behind with the middle layer of the bladder. In the peri- neal ligament this stratum is covered by the constrictor urethras as in tlie male (p. 403). The mucous coat is pale except near the outer orifice. It is marked by longitudinal folds; and one of these, in the floor of the canal, resembles the median crest in the male urethra (p. 526). Around the outer orifice are some mucous follicles ; and towards the inner end are tubular mucous glands^ whose apertures are arranged in lines between the folds of the membrane. A laminar epithelium is spread over the surface, and beneath it are deeper conical cells as in the bladder. A submucous stratum of longitudinal elastic and muscular tissues lies close beneath the mucous membrane, as in the male. Dissection. The rectum may be prepared for examination by distend- ing it with tow, and by removing the peritoneal covering and the areolar tissue from its surface. Rectum. The structure of the rectum is similar in the two sexes ; and the student may use the description in the Section on the viscera of the male pelvis (p. 522). Section YII. INTERNAL MUSCLES OF THE PELVIS. Two muscles, the pyriformis and obturator internus, liave their origin within the cavity of the pelvis. Dissection. Take away any fascia or areolar tissue which may remain on the muscles ; and define their exit from the pelvis, the pyriformis pass- ing through the great sacro-sciatic notch, and the obturator through the small notch of the same name. On the right side the dissector may look to the attachment of the levator ani muscle to the pubic part of the hip- bone. Tlie PYRIFORMIS MUSCLE is directed outwards through the great sacro- sciatic notch to the great trochanter of the femur. The muscle has re- ceived its name from its form. In the pelvis the pyriformis arises by three slips from the second, third, and fourth pieces of the sacrum, between the anterior aperture.*, and from the lateral part of the bone external to those iioles ; as it passes from the pelvis, it takes origin also from the surface of the hip-bone form- ing the upper part of the large sacro-sciatic notch, and from the great sacro-sciatic ligament. From this origin the fibres converge to the ten- don o^ insertion into the trochanter. (Dissection of the B.ittock.) The anterior surface is in contact with the rectum on tlie left side, with the sacral plexus, and with the sciatic and pudic branches of the internal I LIGAMENTS OF PELVIC BONES. 543 iliac vessels. The opposite surface rests on the sacrum, and is covered by the great gluteal muFcle outside the pelvis. The upper border is near the hip-bone, tlie gluteal vessels and the superior gluteal nerve being be- tween : and the lower border is contiguous to the coccygeus muscle, the sacral plexus, and the sciatic and pudic vessels intervening. Action. The pyriformis belongs to the group of external rotators of the hip-joint; and its use will be given with the description of the rest of the muscle in the dissection of the Buttock. The OBTURATOR INTERNUS MUSCLE has its Origin in the pelvis, and insertion at the great trochanter of the femur, like tlie preceding ; but the part outside is almost parallel in direction with that inside the pelvis. The muscle arises by a broad fleshy attachment from the obturator mem- brane, except a small part behind ; i'rom the pelvic fascia covering its sur- face ; slightly from the bone anterior to the thyroid hole, but from all the smooth inclined surface of the pelvis behind and above that aperture, though opposite the small sacro-sciatic foramen a thin layer of fat separates the fleshy fibres from the bone. The fibres are directed backwards and somewhat downwards, and end in three or four tendinous pieces, which turn over the sharp edge of the hip-bone corresponding with the small sacro-sciatic notch. Outside the pelvis the tendons blend into one, which is inserted into the great trochanter. The muscle is in contact by one surface with the wall of the pelvis and the obturator membrane; by the other surface with the pelvic fascia, and towards its lower border with the [)udic vessels and nerve. Action. The muscle draws the trochanter towards the back of the hip- bone over which it bends, and rotates out the hip joint. For further no- tice of its use, see the dissection of the Buttock. CoccYGEus Muscle. The position and the connections of this muscle may be studied with advantage in the interior of the pelvis. The muscle is described at p. 501. LIGAMENTS OF THE PELVIS. The following are the articulations between the bones of the pelvis : — The several pieces of the sacrum and coccyx are united with one another. The sacrum is joined at its base to the last lumbar vertebra, at its apex to the coccyx, and laterally to the two innominate bones. And the innomi- nate bones are connected together in front, as well as to the sacrum and the spinal column posteriorly. Union of Pieces of Sacrum and Coccyx. Whilst the pieces of the sacrum and coccyx remain separate they are articulated as in the other vertebrae by an anterior and posterior common ligament, with a disk of intervertebral substance for the bodies; and by other ligaments for the neural arch and processes (p. 346). After the sacral vertebrap- have coalesced, only rudiments of the liga- ments of the bodies are to be recognized ; but when the pieces of tlie coccyx unite by bone, those ligaments disappear in the adult male. Sacro-vertebral Articulation. The base of the sacrum is articu- lated with the last lumbar vertebra by ligaments similar to those uniting one vertebra to another (p. 346) ; and by one special ligament — the sacro- vertebral. Dissection. For the best manner of bringing these different ligaments 544: DISSECTION OF THE PELVIS. into view, the dissector may consult the directions already given for the dissection of the ligaments of the vertebras (p. 346). The common ligaments for the bodies of the two bones are an anterior and a posterior, with an intervening fibro-cartilaginous substance. Be- tween the neural arches lie the ligamenta subflava; and between the spines the supra and interspinous bands are situate. The articular pro- cesses are united by capsular ligaments with synovial membranes. The sacro-vertehral ligament is a rather strong bundle of fibres, which reaches from the under suH'ace of the tip of the transverse process of the last lumbar vertebra to the lateral part of the base of the sacrum. Widen- ing as it descends, the ligament joins the fibres in front of the articulation between the sacrum and the innominate bone. Sacro-coccygeal Articulation. The sacrum and coccyx are united at the centre by a fibro-cartilage, and by an anterior and posterior common ligament. And there is a separate articulation for the cornua of the bones. Dissection. Little dissection is needed for these ligaments. When the areolar tissue has been removed altogether from the bones, the liga- ments will be apparent. The anterior ligament (sacro-coccygeal) consists of a few fibres that pass between the bones in front of the fibro-cartilage. The posterior ligament is wide at its attachment to the last piece of the sacrum, but narrows as it descends to be inserted into the coccyx. . The Jibro-cartilage resembles that between the bodies of the other ver- tebrae, and is attached to the surfaces of the bones. Articulatioji of the cornua. The cornua of the first piece of the coccyx are united with the cornua of the last sacral vertebra by ligamentous bands, and not by joints as in tlie articular processes of the otlier vertebrae. Movement. Whilst the coccyx remains separate from the sacrum, a slight antero-posterior movement will take place between them. Sacro-iliac Articulation. The irregular surfaces by which the sacrum and the innominate bone articulate, are united by cartilage (syn- chondrosis), and are maintained in contact by anterior and posterior sacro- iliac ligaments. Inferiorly the bones are further connected, without being in contact, by the strong sacro-sciatic ligaments. Dissection. To see the posterior ligaments, the mass of muscle at the back of the sacrum is to be removed on the side on which the innominate bone remains. The anterior bands will be visible on the removal of some areolar tissue. The small sacro-sciatic ligament will be brought into view by removing the coccygeus; and the large ligament is dissected with the lower limb. The anterior sacro-iliac ligament consists of a few thin scattered fibres between the bones, near their articular surfaces. The posterior ligaments (sacro-iliac) are much stronger than the ante- rior, and the fibres are collected into bundles: these ligaments pass from the rough inner surface, at the posterior end of the innominate bone, to the first two pieces of the sacrum. One bundle, which is distinct from the others, and more superficial, is named the oblique or long posterior ligament; it is attached to the posterior upper iliac spinous process, and descends almost vertically to the third piece of the sacrum. Articular cartilage. Between the irregular surfaces of the bones is a thin uneven layer of cartilage (fig. 189, a). It fits into the inequalities of the osseous surfaces, uniting them very firmly together. On separating SACRO-SCTATIC LIGAMENTS. 545 the bones after the other ligaments are examined, the cartilage may be detached with a knife. Movement. There is scarcely any appreciable motion in the sacro-iliac articulation, even when the hip-bone is seized by the hand, and forcibly pulled in different directions. The articulation seems designed for se- curity and little movement, inasmuch as the surfaces are not in contact, are very irregular, and have a firm and inextensible piece of cartilage interposed between them. In some instances, and especially during. preg- nancy, there is a greater degree of motion perceptible. Two sacro-sciatic ligaments pass from the lateral part of the sacrum and coccyx to the hinder border of the os innominatum, across the space between the bones at the back of the pelvis : they are named large and small. The large ligament (fig. 190, a) reaches from the back of the hip bone, and the side of the sacrum and coccyx to the ischial tuberosity. As this Fig. 190. This figure shows the irregular piece of carti- lage (a) in the sacro-iliac articulation. Sacro-sciatic Ligamknts. a. Large or posterior ligament. h. Small or anterior ligament. may have been cut in the examination of the gluteal region, no further notice is given here ; but if it remains entire, see Dissection of the But- tock for its description. The small ligament (fig. 190, h) is attached internally by a wide piece to the border of the sacrum and coccyx, where it is united with the origin of the preceding band. The fibres are directed outwards, and are inserted by a narrowed part into the ischial spine of the hip bone. Its pelvic sur- face is covered by the coccygeus muscle ; and by tie opposite surface it is in contact with the great sacro-sciatic ligament. Above it is the large sacro-sciatic foramen ; and below it is the small foramen of the same name, which is bounded by the two ligaments. By their position these ligaments convert into two foramina (sacro- sciatic), the large sacro-sciatic excavation in the dried bones : the open- ings, and the parts they give passage to, are described with the Buttock. 35 546 DISSECTION OF THE PELVIS, Ligaments of the Innominate Bones (fig. 191). The innominate bones are united in front, at the pubic symphysis, by an interposed piece of cartilage and special ligaments ; and behind, each is connected with the transverse process of the last lumbar vertebra by a separate band (ilio- lumbar). In the centre of the bone is a membranous structure closing the thyroid aperture. The ilio-lumhar or ilio-vertehral ligament is triangular in form and is divided into fasciculi. Internally it is attached to the tip of the trans- verse process of the last lumbar vertebra ; externally the fibres spread out, Anterior ligament of the symphysis ; d, inferior, and c, cartilage of the sym- physis, with a slit in the middle. Obturator membrane. Surface of the acetabulum covered with cartilage. Fatty substance in the acetabulum. Cotyloid ligament, which is cut where it forms part of the transverse band over the notch. Deep part of the ligament over the coty- loid notch. Ligaments of the Symphysis Pubis, Thyroid Hole, and Acetabulum. and are inserted into the iliac-crest for about an inch, opposite the poste- rior part of the iliac fossa. To the upper border of the ligament the fascia lumborum is attached; its posterior surface is covered by the quadratus lumborum, and its anterior by the iliacus muscles. Tlie thin obturator membrane (fig. 191, h) closes almost entirely the thyroid foramen, and is composed of fibres crossing in different directions. It is attached to the bony margin of the foramen, except above where the obturator vessels pass through ; and towards the lower part of the aperture it is connected to the pelvic aspect of the hip-bone. The surfaces of the ligament give attachment to the obturator muscles. Branches of the ob- turator vessels and nerve perforate it. Pubic Articulation (fig. 191, a) (symphysis pubis). The oval pubic surfaces of the hip bones are united by cartilage, and by fibres in front of, and above the bones : they are also connected by a strong subpubic ligament. The anterior pubic ligament (fig. 191, a) is very strong and is formed of difierent layers of fibres. The superficial are oblique, and cross one another, joining with the aponeurosis of the external oblique muscle of SYMPHYSIS PUBIS. 547 the abdomen ; but the deeper fibres are transverse between the surfaces of the bones. Some of the deepest fibres contain cartilage cells. There is not any strong posterior band ; but beneath the periosteum are a few scattered fibres in contact with the articular cartilage. The superior ligamentous fibres fill the interval between the bones above the cartilage. The subpubic ligament (fig. 191, d) (ligam. arcuatum) is a strong tri- angularly-shaped band below the symphysis, and occupies the upper part of the pubic arch. The apex of the ligament touches the articular carti- lage, and the base, contained within the triangular perinaeal ligament, is turned towards the membranous part of the urethra. Dissection. The cartilage will be best seen by a transverse section of the pubes, which will show the disposition of the anterior ligament of the articulation, and the thickness of the cartilage, with its toothed mode of insertion into the bone ; but when opportunity offers, a vertical section may be made. Cartilage (fig. 191, c). The cartilage is firmly fixed to the ridged bony surfaces of the symphysis : it is wider above than below, and is generally as thick again before as behind. Variations in its size depend on the shape of the bones. Towards the posterior part of the cartilage there is a narrow fissure with uneven walls ; and a fibrous structure with large interspersed com- pound cells is to be recognized in the wall. It extends usually the whole depth of the cartilage and through a half or a third of the thickness : it is said to increase in pregnancy. In some bodies it reaches through the cartilage so as to divide this into two collateral pieces. Movement. As the bones are not in contact in the pubic symphysis, but are united by an intermediate cartilage, the motion is usually very slight. The kind of movement of the hip bone is inward and outward, so as to increase or diminish the pelvic cavity. When the pubic cartilage is divided into two by a larger central space than usual, greater freedom of motion is present in the symphysis ; and in pregnancy the looseness of the innominate bone is sometimes so great as to interfere seriously with locomotion. 518 ARTERIES OF THE ABDOMEN. TABLE OF THE ARTERIES OF THE ABDOMEN. f 1. Phrenic. o 2. Cocliac axis* 3. superior lueseuteric* 4. middle capsu- lar renal spermatic inferior mesenteric* Coronary hepatic (^ splenic r Pancreatic I intestinal ~{ ileo-colic I right colic middle colic Left colic sigmoid superior hasmorrhoidal (Esophageal gastric. Superior pyloric gastro-epiploic left hepatic branch right hepatic blanch pancreatic va*'y. pudic . visceral branches obturator Articular, Middle hamorrhoidal vesical uterine vaginal. » The branches marked with an asterisk are single. VEINS OF THE ABDOMEN. 549 TABLE OF THE VEINS OF THE ABDOMEN. Visceral branches Internal iliac ■< fl. Common iliac. .^ Vertebro-lumbar right spermatic renal right capsular diaphragmatic hepatic veins which bring blood from the vena portse. f Splenic external iliac ilio-lumbar lateral sacral middle sacral into the left. Eight left , ( Epigasti } circumfl ( iliac trie ex capsular spermatic Vena portje Splenic branches vasa brevia pancreatic left gastro- epiploic inferior mesenteric ' Intestinal ileo-colic right colic middle colic superior mesenteric -^ right gastro- epiploic pancreatic pancreatico- duodenal coronary t. cystic ' Hsemorrhoidal plexus r Vesical vesico-prostatic j dorsal of the penis plexus 1 deep veius of the i_ penig. uterine _ vaginal. Obturator pudic . parietal , branches "^ ^ gluteal. r Left coli( sigmoid <| superior hseraor- rhoidal. ' Veius of corpus ca- vernosum of the bulb transverse perinsoal superficial peripseal inferior hajmor- rhoidal. r coccygeal J comes nervi i dici muscular. ichia- 550 SPINAL NERVES OF THE ABDOMEN. TABLE OF THE SPINAL NERVES IN THE ABDOMEN. f Posterior branches Lumbar SPINAL NERVES divide into . . Anterior branches : of these the four first end in the Lumbar ^ PLEXUS,* which supplies . . . Internal external Ilio-hypogastric ilio-inguinal external cuta- neous . . genito-crural , anterior crural obturator Muscular < Ml ( cu Muscular taneous. Cutaneous of the ilium hypogastric branch. ( To integuments of ( tlie groin. J To integuments of ( the thigh. J Genital branch I crural branch. Branches inside the pelvis Branches outside the pelvis . . Accessory To the iliacus muscle. To the femoral artery. are noticed in thigh. Other offsets are described in the thigh. * The lumbo-sacral gives off the superior gluteal nerve. Sacral SPINAL NRRVES divide into . . ' Posterior branches unite together and give off ... . The anterior branches of the four superior unite with the lum- bo-sacral in the sa- cral PLEXUS,! and furnish Muscular and cutaneous filaments. Branches inside the pelvis branches outside the pelvis . . Visceral to levator ani to ol)turator internus to the pyriformis f pudic inferior hsemor- rhoidal (sometimes). to the gluteus maxi- mus to the superior ge- mellus to the inferior ge- mellus and the quadratus articular small sciatic 1^ great sciatic. f Inferior hajmorrhoidal superficial perinseal (an- terior and posterior) muscular to the bulb dorsal of the penis. these are de- scribed in the Thigh. t The other sacral nerves are described at p. 518. NERVES OF THE ABDOMEN 551 TABLE OP SYMPATHETIC NERVE OP THE ABDOMEN. !XFs* or pre- centre of the furnishes the " plexuses : Diaphragmatic coeliac Coronary plexus hepatic ... Pyloric right gastro-epiploic pancreatico-duodenal cystic. Left gastro-epiploic pancreatic. superior mesenteric suprarenal renal aortic Hypogastric. spermatic *- inferior mesenteric ^ splenic . . . Offsets to small and large intestine Spermatic plexus, filaments to the. Offsets to the large intestine Superior hsemorrhoidal. * This receives ( Great splanchnic nerves. . . . < part of small splanchnic ( offset of pneumogastric. Hypogastric Plexus-j- ends in the pelvic plexus on each side, which gives the follow- ing plexuses . . . . inferior hsemorrhoidal uterine vaginal Prostatic cavernous deferential to vesiculse seminales. External branches Ganqltated cord of the sympathetic in the ab- domen supplies . . . internal t This is joined above by To the lumbar and sacral spinal nerves. To aortic plexus to hypogastric plexus to join I'ound middle sacral artery between the cords on the coccyx, in the ganglion impar. The aortic plexus filaments from the lumbar ganglia. PNEUMOGASTRIC NERVE IN THE ABDOMEN r Right . Pneumogastric < Coronary branches to the back of the stomach • \ filaments to join the cooliac and splenic plexuses. jgf. < Coronary branches to the front of the stomach, and \ to the hepatic plexus. 652 DISSECTION OF THE THIGH. CHAPTER IX. DISSECTION OF THE LOWER LIMB. Section I. THE FRONT OF THE THIGH. All the parts described in Section I. are to be examined before the time for turning the body arrives. Position. During the dissection of the front of the thigh the body lies on the back, with the buttocks resting on the edge of the table, and with a block of suitable size beneath the loins. The lower limb should be sup- ported in a half-bent position by a stool beneath the foot, and should be rotated outwards to make evident a hollow at the upper part of the thigh. Surface marking. Before any of the integument is removed from the limb, the student is to observe the chief eminences and hollows on the surface of the thigh. The limit between the thigh and abdomen is marked, in front, by the firm band of Poupart's ligament reaching from the crest of the hip bone to the pubes. On the outer side, the separation is indicated by the con- vexity of the iliac crest of the hip bone, which subsides behind in the sacrum and coccyx. On the inner side is the projection of the pubes, from which a line of bone (pubic arch) may be traced backwards along the inner and upper parts of the limb to the ischial tuberosity. On the anterior aspect of the thigh, and close to Poupart's ligament, is a sliglit hollow, corresponding with the triangular space of Scarpa, in which the larger vessels of the limb are contained ; and extending thence obliquely towards the inner side of the limb, is a slight depression mark- ing the situation of the femoral artery beneath. The position of the arterial trunk may be ascertained by a line from the centre of the interval between the symphysis pubis and the crest of the hip bone, to the inner condyle of the femur. At the outer side of the^high, about four inches below and behind the anterior part of the iliac crest, the well-marked projection of the great trochanter of the femur will be recognized. In a thin body the head of the femur may be felt by rotating the limb inwards and outwards, whilvSt tlie thumb of one hand is placed in the hollow below Poupart's ligament, or tlie fingers behind the great trochanter. At the knee tlie outline of the several bones entering into the formation of the joint may be traced with ease. In front of the joint, wlien it is half-bent, tlie rounded prominent patella may be perceived ; this bone is firmly fixed whilst the limb is kept in the same position, but is moved with great freedom when the joint is extended, so as to relax the muscles I ANATOMY OF SUPERFICIAL PARTS. 653 inserted into it. On each side of the patella is the projection of the con- dyle of tlie femur, but that on the inner side is the largest. If the fingers are passed along the sides of the patella whilst tlie joint is half-bent, they will be conducted to the tuberosities of the head of the tibia, and to a slight hollow between the bones. Behind the joint is a slight dspression over the situation of the ham or popliteal space ; and on its sides are firm boundaries, which are formed by the tendons (hamstrings) of the flexor muscles of the leg. Dissection. With tlie position of the limb the same as before directed, the student begins the dissection with the examination of the subcutaneous fatty tissue with its nerves and vessels. At first the integument is to be reflected only from the hollow on the front of the thigh close below Poupart's ligament. To raise the skin from this part, an incision about four inches in length, and only skin deep, is to be made from the pubes along the inner border of the thigh. At the lower end of the first incision, another cut is to be directed outwards across the front of the limb to the outer aspect ; and at the upper end the knife is to be carried along the line of Poupart's ligament as far as the crest of the hip bone. The piece of skin included by these incisions is to be raised and turned outwards, without taking with it the subcutaneous flxt. The subcutaneous fatty tissue, or the superficial fascia, forms a general investment for the limb, and is constructed of a network of areolar tissue, with fat or adipose substance amongst the meshes. As a part of the com- mon covering of the body, it is continuous with that of the neighboring regions, consequently it may be followed inwards to the scrotum or labium, and upwards on the abdomen. Its thickness varies in different bodies, according to the quantity of fat in it ; and at the upper part of the thigh it is divisible into two strata (superficial and deep) by some cutaneous vessels and inguinal glands. The superficial of the two layers is apparent after the removal of the skin, but its connections will be made more evident by the following dissection. Dissection. To reflect the superficial stratum of the fascia, incisions similar to those in the skin are to be employed, though the transverse one is not to reach so low on the thigh by a couple of inches ; and the separa- tion from the subjacent structures is to be begun at the lower part, where the large saphenous vein, and a condensed or membranous appearance on the under sui-face, will mark the depth of the stratum. This layer of the fat may be thrown upwards readily, by a few touches of the knife along the middle line of the limb; but where vessels and glands are not found, viz., along the outer and inner borders of the thigh, the separation of the superficial fascia into two layers cannot be easily made. The subcutaneous layer of the fat decreases in thickness near Poupart's ligament, becoming more fibrous at the same spot ; and at its under aspect is a smooth and membranous surface. It conceals the superficial vessels and the inguinal glands, and is separated by these from Poupart's liga- ment. Dissection (fig. 193). The inguinal glands and the superficial vessels are to be next laid bare by the removal of the surrounding fat ; but the student is to be careful not to destroy the deeper, very thin layer of the superficial fascia, which is beneath them, and is visible chiefly on the inner side of the centre of the limb. Three sets of vessels are to be dis- sected out : — One set (artery and vein) is directed inwards to the pubes, 554 DISSECTION OF THE THIGH. and is named external pudic ; another, superficial epigastric, ascends over Poupart's ligament ; and the third, or the superficial circumflex iliac, appears at the outer border of the limb. The large vein in the middle line of the thigh to which the branches converge, is the internal saphenous. Some of the small lymphatic vessels may be traced from one inguinal gland to another. A small nerve, the ilio-inguinal, is to be sought on the inner side of the saphenous vein, close to the pubes ; and the branch of the genito-crural nerve, or an offset of it, may be found a little outside the vein. Superficial Vessels. The small cutaneous arteries at the top of the thigh are the first branches of the femoral trunk ; they pierce the deep fascia (fascia lata), and are distributed to the integuments and the glands of the groin. The external pudic artery (h) (superior) crosses the spermatic cord in its course inwards, and ends in the integuments of the penis and scrotum, where it anastomoses with offsets of the internal pudic artery. Another external pudic branch (inferior, p. 565) pierces the fascia lata at the inner border of the thigh, and ramifies also in the scrotum. In the female both branches supply the labium pudendi. The superficial epigastric artery (c) passes over Poupart's ligament to the lower part of the abdomen (p. 407), and communicates with branches of the deep epigastric artery. The superficial circumflex iliac artery (c?) is the smallest of the three branches : appearing as two or more pieces on the outer border of the thigh near the iliac crest, it is distributed in the integuments : it supplies an offset with the external cutaneous nerve. A vein accompanies each artery, having the same name as its companion vessel ; and ends in the upper part of the saphenous vein, with the excep- tion of that with the inferior pudic artery : but the description of these veins will be given in a subsequent page. The superficial inguinal glands (e) are ari'anged in two lines. One set lies across the thigh, near Poupart's ligament; and the other is situate along the side of the saphenous vein. In the lower or femoral group the glands are larger than in the upper, and the lymphatic vessels from the surface of the lower limb enter them. The upper or abdominal group is joined by the lymphatics of the penis, by those of the lower part of the abdomen, and by those of the buttock. Tlie glands vary much in number and size ; and not unfrequently the longitudinal set by the side of the vein are blended together. Dissection. The deeper layer of the superficial fascia is to be detached from the subjacent fascia lata. Internal to the saphenous vein a thin membrane can be raised by transverse cuts above and below, and by a longitudinal one on the inner side of the thigh ; but external to that vessel there exists scarcely a continuous layer. The handle of the scalpel may be employed in the separation ; and the dissector is to avoid injuring the nerves and vessels. In reflecting the stratum the margin of an aperture (saphenous) in the fascia lata will become apparent. The deeper layer of the superficial fascia is a very thin membraniform stratum, which is most evident near Poupart's ligament, and on the inner side of the saphenous vein. About one inch below the ligament it conceals the large saphenous opening in the fascia lata; and as it stretches across the aperture it is attached to the circumference — internally by loose areolar CUTANEOUS VEINS AND NERVES. 555 tissue, but externally by firm fibrous bands ; it is also connected with the loose crural sheath of the subjacent vessels in the aperture. The part of the stratum over the saphenous opening is perforated by many small apertures for the transmission of the lymphatics ; and it has been named cribriform fascia from its sieve-like appearance. In a hernial protrusion through tliat opening the cribriform portion is projected forwards by the tumor, and forms one of the coverings. Dissection. Now the student has observed the disposition of the super- ficial fascia near Poupart's ligament, he may proceed to examine the remainder of the subcutaneous covering of the thigh, together with the vessels and nerves in it. To raise the skin from the front of the thigh, a cut is to be carried along the centre of the limb, over the knee joint, to rather below the tu- bercle of the tibia. At the extremity a transverse incision is to be made across the front of the leg, but this is to reach farthest on the inner side. The skin may be reflected in flaps inwards and outwards ; and as it is raised from the front of the knee a superficial bursa between it and the patella will be opened. The saphenous vein is first to be traced out in the fat as far as the skin is reflected, but in removing the tissue from it the student should be care- ful of branches of the internal cutaneous nerve. The cutaneous nerves of the front of the thigh (fig. 192) are to be sought in the fat, Mnth small cutaneous arteries, in the following positions : On the outer margin, below the upper third, is placed the external cuta- neous nerve. In the middle of tlie limb, below the upper third, lie the two branches of the middle cutaneous nerve. At the inner margin are the ramifications of the internal cutaneous nerve — one small offset appearing near the upper part of the thigh ; one or more about half way down ; and one of the terminal branches (anterior) about the lower third. On the inner side of the knee three other cutaneous nerves are to be looked for : One, a branch of the great saphenous, is directed outwards over the middle of the patella. Another, the trunk of the great saphenous nerve, lies by the side of the vein of the same name, close to the lower part of the surface now dissected. And the third is a terminal branch (inner) of the internal cutaneous nerve, which is close behind the pre- ceding, and communicates with it. Vessels. All the cutaneous veins on *he anterior and inner aspects of the thigh are collected into one ; and this trunk is named saphenous from its manifest appearance on the surface. The internal saphenous vein (fig. 193, a) is the cutaneous vessel of the inner side of the lower limb, and extends from the foot to the upper part of the thigh. In the part of its course now dissected, the vessel lies infe- riorly somewhat behind tlie knee-joint ; but as it ascends to its termina- tion, it is directed along the inner side and the front of the thigh. Near Poupart's ligament it pierces the fascia lata by a special opening named saphenous, and enters the deep vein (femoral) of the limb. Superficial branches join it both externally and internally ; and near Poupart's ligament the three veins corresponding with the arteries in that situation, viz., external pudic (6), superficial epigastric (c),and circumflex iliac (c?), terminate in it. Towards the upper part of the limb the veins of the inner side and back of the thigh are most frequently united into one branch, which enters the saphenous trunk near the aperture in the fascia lata ; and sometimes those on the outer side of the thigh are collected to- 556 DISSECTION OF THE THIGH, Fig. 192. gether in a similar way. When this arrangement exists three large veins will be present on the front of the thigh, near the saphenous opening. On the side of the knee the vein receives a deep branch from the joint. Some unnamed cutaneous arteries are distributed to the integuments along with the nerves ; and the superficial branch of the anastomotic artery (p. 568) accompanies the saphenous nerve and its branches near the knee. Nerves. The cutaneous nerves of the thigh are derived from branches of the lumbar plexus, and are distributed in greater number on the inner than the outer side. llio-inguinal. This nerve (p. 497) is small in size, and reaches the surface by passing through the external ab- dominal ring (fig. 192, ^) ; it supplies the scrotum, and ends in the contiguous part of the thigh, internal to the saphenous vein. The Genito-crural. The crural branch of this nerve (p. 497) pierces the fascia lata near Poupart's ligament (fig. 192, ^), rather external to the line of the femoral artery. After or before the nerve has become super- ficial it communicates with the middle cuta- neous nerve ; and it extends on the anterior aspect of the thigh as far as midway between the knee and the pelvis. Occasionally this branch is of large size, and takes the place of the external cutaneous nerve on the outer side of the limb. • The external cutaneous nerve (p. 497) ramifies on the outer aspect of the limb (fig. 192, ^). At first it is contained in a promi- nent ridge of the fascia lata on the outer mar- gin of the thigh, where it divides into an an- terior and a posterior branch. The posterior branch subdivides into two or three others, which arch backwards to supply the integuments of the outer part of the thigh as low as the middle. The anterior branch appears on the sur- face of the fascia lata about four inches from Poupart's ligament, and is continued to the knee ; it distributes branches laterally, but those towards the posterior surface are the most numerous, and the largest in size. Middle cutaneous (fig. 192, ^). The nerve of the centre of the thigh is a cutaneous offset of the anterior crural (p. 497), and divides into two branches. It is transmitted through the fascia lata about three inches from Pou- part's ligament, and its branches are con- tinued to the knee. In the fat this nerve is united with the genito-crural and internal cutaneous nerves. Internal cutaneous. Derived from the an- furnished to all the inner side of the Cutaneous Nerveson the Front OF THE Thigh. External cutaneous. Middle cutaneouH. Internal cutaneous. Internal saphenous. Patellar branch of saphenous. 6. Genito-crural. 7. llio-inguinal. S. Ilio-hypogastric on the belly. terior crural trunk, this nerve CUTANEOUS NERVES OF THIGH. 557 thigh. It is divided into two branches (anterior and inner), which perfo- rate the fascia in separate places. The anterior branch becomes cutaneous in the lower third of the thigh, in the line of the inner intermuscular septum (fig. 192, ^), along which it is continued to the knee. This branch is distributed in the lower third of the thigh, as well as over the patella and the inner side of the knee- joint, and is united with the patellar branch of the internal saphenous nerve. The inner branch (fig. 207, ®) perforates the fascia at the inner side of the knee behind the internal saphenous nerve, with which it communi- cates ; it furnishes offsets to the inside of the knee, and to the upper half of the leg on the inner surface. Other small offsets of the nerve supply the inner side of the thigh, and appear by the side of the saphenous vein. One or two come into view near the upper part of the vein, and reach as far as the middle of the thigh ; and one, larger in size than the rest, becomes cutaneous where the others cease, and extends as far as the knee. The internal saphenous (fig. 192, *), a branch of the anterior crural, is continued to the foot, but only a small part of it is now visible. The nerve pierces the fascia on the inner side of the knee; and, after commu- nicating with the inner branch of the internal cutaneous, gives forwards some offsets over the knee-joint. Finally it accompanies the saphenous vein to the leg and foot. Its patellar branch (fig. 192, ^) appears on the inner side of the knee above the preceding, and is soon joined by the internal cutaneous nerve. It ends in many branches over the patella ; these communicate with offsets from the middle and external cutaneous nerves, and form an interlace- ment— plexus patellce — over the joint. Dissection. Let the fat and the inguinal glands be now removed from the surface of the fascia lata, the cutaneous nerves being thrown aside to be traced afterwards to their trunks. At the upper part of the thigh the student is to define the saphenous opening in the fascia lata by detaching the superficial fascia. The inner side is easily shown. But the outer border is blended with the superficial fascia and with the subjacent crural sheath ; and it is only after the uniting fibrous bands are broken or cut through that its semilunar edge comes into view. • The fascia lata is the deep aponeurosis of the thigh. It surrounds the limb with a firm sheath, and sends inwards septa between the different muscles. This membranous investment is of a bluish-white color, but in fat bodies is sometimes so slight as to be taken away with the subcu- taneous fat. It is much stronger on the outer than the inner aspect of the limb where it receives the insertion of the tensor vaginae femoris, and the greater part of the gluteus maximus muscle. This thickened part (ilio-tibial band) is attached above to the hip-bone and below to the bones of the leg, and helps the extensor muscle to keep the knee-joint straight in standing. Numerous apertures exist in the fascia for the transmission of the cuta- neous nerves and vessels ; and the largest hole is near Poupart's ligament, to permit the passage of the internal saphenous vein. Processes prolonged from the under surface form septa between, and fibrous sheaths around the several muscles. Two of the processes are larger than the rest, and are named outer and inner intermuscular septa of 558 DISSECTION OF THE THIGH. the thigh : they are fixed to the femur, so as to limit on the sides the extensor of the knee. The position of these partitions is marked on the surface by white lines. At the top of the thigh the fascia is fixed to the prominent borders of the pelvis. Thus it is connected externally with the iliac crest, and inter- nally with the pubes and the pubic arch. In the middle line behind it is joined to the lower end of the sacrum and coccyx ; and in front, to Pou- part's ligament between the pubes and the iliac crest. Behind the knee- joint the fascia passes uninterruptedly to the leg ; but in front of the ar- ticulation it blends with an expansion from the extensor muscle, an^d is continued over the joint and the patella, though separated from that bone by a bursa, to be inserted into the heads of the tibia and fibula. On each side of the patella is a band of almost transverse fibres (reti- naculum) which is attached to and supports the knee-cap. The outer. Fig. 193. Vessels : a. Saphenous vein. 6. Superficial pudic. c Superficial epigastric. d. Superficial circumflex iliac. e. Inguinal glands. /. Saphenous opening. Nerves: 1. Ilio-inguinal. 2. External cutaneous. 3. Genito-crural. 4. Middle cutaneous. Small unnamed vessels accompany the different nerves to the teguments. Dissection of the Superficial parts of the Thigh (Illustrations of Dissections). thick and strong, is continuous externally with the ilio-tibial band, and joins the insertion of the vastus externus at its attachment to the upper part of the patella: it guides the patella outwards when the joint is bent. The inner band, of slight strength, is fixed to the patella lower than the other, and unites with the insertion of the inner vastus. Directions. The flaps of skin wliich were removed from the front of the thigh, to follow the cutaneous vessels and nerves, are to be now PARTS CONCERNED IN FEMORAL HERNIA. 559 itched together to keep moist the subjacent parts ; and the saphenous opening is to be learnt. The saphoneous opening in the fascia lata (fig. 193,/) is a narrow semi- lunar slit, which is situate rather to the inner side of the middle line of the thigh. It measures about a third of an inch in width, and one inch and a half in length. Its upper extremity (superior cornu) is at Pou part's liga- ment; and its lower extremity (inferior cornu) is distant from that struc- ture about one inch and a half, and presents a well-defined margin. The inner part of the opening is posterior to the level of the femoral vessels, and is flattened over the subjacent muscle (pectineus) ; but it is marked below by a thin and sharp border. The outer boundary is much stronger, and has a semilunar border when detached, whose concavity is turned downwards and inwards. This edge is named from its shape ya/c?y<9rm margin of the saphenous opening (falci- form process of Burns) ; it is superficial to the femoral vessels, and is con- nected by fibrous bands to the crural sheath, and to the deeper layer of the superficial fascia. Traced upwards, the outer edge blends with the base of Gimbernat's ligament (part of Poupart) : the upper end of this border, where it is internal to the subjacent femoral vein, has been named the femoral ligament. The rigidity of the margin of the opening is much influenced by the position of the limb; for with the finger beneath the upper part of the falciform border, whilst the thigh is moved in difl'erent directions, this band will be perceived to be most unyielding when the limb is extended and rotated out, and most relaxed when the thigh is bent and turned in the opposite direction. Through the lower part of the opening the saphenous vein is transmit- ted : and through the upper part, close to the falciform edge, a femoral hernia projects. Lymphatics and one or two superficial vessels also pass through it. PARTS CONCERNED IN FEMORAL HERNIA. To obtain a knowledge of the hernial protrusion in the thigh, the dis- sector has to study the undermentioned parts, viz., the crural arch and Gimbernat's ligament, the crural sheath with its crural canal and ring, together with a partition (septum crurale) between the tliigh and the abdomen. Dissection (fig. 194). To examine Poupart's ligament and a loose membranous sheath around the femoral vessels, the piece of the fascia lata outside the saphenous opening is to be reflected inwards by the following incisions: One cut is to be begun near the edge of the falciform border, and to be carried outwards for one inch and a half, parallel and close to Poupart's ligament. Another is to be directed obliquely downwards and inwards from the termination of the first, to a little below the inferior cornu of the opening. When the fascia marked out by those incisions has been raised and turned inwards, and the fat removed, the tube on the ves- sels (crural sheath) will be brought into view as it descends beneath Pou- part's ligament. With the handle of the scalpel the crural sheath is to be separated carefully from the fascia lata beneath, from Poupart's ligament in front, and from Gimbernat's ligament on the inner side. Pouparfs ligament (fig. 194, ^j, or the crural arch, is the firm band of 560 DISSECTION OF THE THIGH. the aponeurosis of the external oblique muscle of the abdomen, which stretches from the front of the iliac crest to the pubes (p. 411). When viewed on the surface, the arch is curved downwards towards the limb, whilst the fascia lata remains on the thigh. The outer half is oblique. But the inner half is almost horizontal, and widens as it approaches the pubes, where it is inserted into the pubic spine and pectineal line of the hip bone, forming Gimbernat's ligament. The space between the crural arch and the innominate bone is larger in the female than in the male, and is closed by parts passing from the abdo- men to the thigh. The outer half of the interval is filled by the fleshy psoas and iliacus muscles, to which the arch is closely bound by fascia ; and the inner half is occupied by the femoral vessels and their sheath. Gimhernafs ligament^ or the part of the"tendon of the external oblique muscle which is inserted into the pectineal line, is about three-fourtlis of an inch in length, and is triangular in shape. Its apex is at the pubic spine ; whilst its base is in contact with the crural sheath, and is joined by the fascia lata. By one margin (anterior) it is continuous with the crural arch, and by the opposite it is fixed to the pectineal line. In the erect position of the body the lio^ament is almost horizontal. The crural sheath (fig. 194, ^) is a loose tube of membrane around the femoral vessels. It has the form of a funnel, sloped unequally on the sides. The wide part or base of the tube is upwards ; and the narrow part ceases about two inches below Pou part's ligament, by blending with the common areolar sheath of the bloodvessels. Its outer border is nearly straight, and is perforated by the genito-crural nerve (^). Its inner border is oblique, and is pierced by lymphatics, superficial vessels, and the saphenous vein(/) ; this part of the sheath appears in the saphenous opening, and is connected to the falciform margin and the superficial fascia. In front of the crural sheath and behind it is the fascia lata of the thigh. The sheath is continuous with the fascia? lining the abdomen in this way ; the anterior part is prolonged beneath Poupart's ligament into the fascia transversalis, and the posterior half is continued into the fascia iliaca (p. 428). Crossing the front of the sheath beneath the arch of Poupart's ligament, is a fibrous band, the deep crural arch. A notice of it is included in the description of the fascia transversalis (p. 419). Dissection (fig. 194). The student is to open the sheath by an incision across the front, and to raise the loose anterior part with hooks. Inside the tube are contained the femoral vessels, each surrounded by its covering of areolar tissue, together with an inguinal gland ; and if a piece of the areolar casing be cut out over both the artery and the vein, there will be an appearance of two thin partitions, the one being situate on the inner side of the vein, separating this vessel from the gland, and the other (J) between the vein and the artery. A fatty stratum stretches over the upper aperture of the sheath, closing it towards the abdomen. Interior of the crural sheath (fig. 194). The sheath is said be be divided into three compartments by two partitions ; and the position of the so- called septa has been before referred to — one being internal to the femoral vein, and the other between the two large vessels. In the outer compart- ment is contained the femoral artery (a), lying close to the side of the sheath ; in the middle one is placed the femoral vein (b) ; and in the inner space (crural canal) only a lymphatic gland (c) is situate. The crural canal (fig. 192) is the innermost space in the interior of the ANATOMY OF FEMORAL HERNIA 561 crural sheath : Its length is about a third of an inch, and it reaches from the base of Gimbernat's ligament to the upper part of the sapenous opening. It decreases rapidly in size from above down, and is closed below. The aperture by which the space communicates with the cavity of the abdomen is named in the crural ring. Fig. 194. A. Fascia lata reflected. B. Crural sheath opened, c. Poupart's ligament. D. Fascia late of the thigh in place. X Two septa dividing the space of the crural sheath into three com- partments. Vessels : a. Femoral artery. b. Femoral vein ; and c. A lymphatic gland, all in the crural sheath. d. Superficial circumflex iliac. e. Superficial pudic. /. Saphenous vein. Nerves : 1. Genito-crural. 2. Ilio-inguinal. 4. External cutaneous. Dissection of the Crural Sheath (Illustrations of Dissections). Anterior to the canal, are Poupart's ligament and the upper end of the falciform margin of the saphenous opening ; whilst behind it is the pecti- neus muscle, covered by fascia lata. On the outer side of the canal, but in the sheath, is the femoral vein. Through this channel the intestine passes from the abdomen in femoral hernia. The crural ring^ is the upper opening of the crural canal. It is on a level with the base of Gimbernat's ligament (fig. 142, ^), and is larger in the female than in the male. Oval in shape, its greatest measurement is from side to side, in which direction it equals about half an inch ; and it is filled by a lymphatic gland. The structures around the ring, outside the crural sheath, are similar to those bounding the canal, viz., in front the superficial and the deep crural arch, and behind, the pubes covered by the pectineus muscle iand the fascia lata. Internally is Gimbernat's ligament with the conjoined tendon ; and externally (but within the sheath) is the femoral vein. The position of vessels on the several sides of the ring is stated at page 429. Septum crurale. That part of the subperitoneal fatty layer which is placed over the opening of the crural ring, has been named crural septum from its position between the thigh and abdomen (Cloquet). The situa- ' Gimbernat used tlie name crural ring, and Mr. Lawrence proposes to call it femoral aperture. Might not the nomenclature be made to resemble more that used in describing inguinal hernia, by calling this opening the internal crural aperture, and the saphenous opening the external crural aperture ? 36 562 DISSECTION OF THE THIGH. tion of the septum is now visible, but its characters are ascertained in the dissection of the abdomen (p. 428). Femoral Hernia. In this kind of hernia there is a protrusion of in- testine into the thigh beneath Pou part's ligament. And tlie gut descends in the crural sheath, being placed on tin; inner side of the vein. Course. At first the intestine takes a vertical direction in its progress from the abdomen, and passes through the crural ring, and along the crural canal as far as the saphenous opening. At this spot it changes its course, and is directed forwards to the surface of the thigh, where it becomes elongated transversely; and should the gut protrude still farther, the tumor ascends on the abdomen, in consequence of the resistance being less in this direction than on the front of the thigh. The winding course of the hernia may suggest to the dissector the direc- tion in which attempts should be made to replace the intestine in the ab- dominal cavity. With the view of making the bowel retrace its course, it will be necessary if the protrusion is small to direct it backwards and upwards ; but if the hernia is large it must be pressed down first to the saphenous opening, and afterwards backwards and upwards towards the crural canal and ring. During the manipulation to return the intest'ne to its cavity the thigh is to be raised and rotated inwards, in order tliat the margin of the saphe- nous opening and the other structures may be relaxed. Coverings. As the intestine protrudes it is clothed by the following layers, which are elongated and pushed before it from within outwards. First is a covering of the peritoneum lining the abdomen, which forms the hernial sac. Next one from the septum crurale across the crural ring. Afterwards comes a stratum from the crural sheath, unless the hernia bursts through an aperture in the side. Over this is spread a layer of the cribriform fascia. And, lastly, there is an investment of the superficial fat or fascia, together with the skin. The coverings may vary, or may be conjoined in different degrees ac- cording to the condition of the hernia. In some instances the prolonga- tion from the crural sheath is wanting. Further, in an old hernia the covering derived from the septum crurale is united usually with that from the crural sheath, so as to form one layer, the fascia propria (Cooper). In general, in an operation for the relief of the strangulated bowel, the surgeon, after dividing the subcutaneous fat, can recognize but little of the coverings enumerated by anatomists until he meets with that of the sub- peritoneal fat or septum crurale. Diagnosis. This hernial tumor is generally smaller than inguinal, and does not extend into the scrotum in the male, or the labium in the female ; and if its neck can be traced below Poupart's ligament, it can be distin- guished certainly from an inguinal hernia. Seat of stricture and division of it. The strangulation of a femoral hernia may be situate either outside or inside the neck of the sac. The external stricture may be found opposite the margin of the saphe- nous opening, or deeper in, opposite Poupart's ligament. It may be re- moved by cutting down on the neck of tiie tumor at the inner side, and dividing the constricting band arching over the neck of the hernia in this situation, witliout opening the sac. The stricture inside the neck of the sac is occasioned by the thickening of the peritoneum. For its relief the neck of the sac is to be laid bare, as if there was an external stricture ; and if the intestine cannot be passed SCARPA'S TRIANGULAR SPACE 563 into the abdomen after division of all constricting bands on the exterior of tlie neck, the sac of the peritoneum is to be opened ; and a director having been introduced through the constriction, a cut is made horizontally inwards for the extent of one or two lines. The several vessels that may be wounded in attempting to relieve the deep stricture are enumerated at page 429. Scarpa's triangular space. This hollow is situate at the upper part of the thigh, and lies beneath the depression observable near Poupart's ligament. It corresponds with the axilla in the upper limb. Dissection (fig. 195). The space will appear on removing the fascia lata near Poupart's ligament. The muscular boundaries on the sides may be first dissected, and the muscle on the outer side (sartorius) should be fixed in place with stitches. Afterwards, the remains of the crural sheath Fi?. 195. Muscles: A. Sartorius. B. Iliacus. C. Tensor fasciae latse. D. Rectus feraoris. E. Pectineus, F Adductor longus. a. Gracilis. / Vessels : a. Femoral artery. 6. Superficial circumflex iliac. ('. Superficial epigastric. e. Superficial pudic (inferior) , and z, the accompanying veins. Deep circumflex iliac. Deep epigastric. Femoral veiu. Inferior external pudic vein. Saphenous vein. Nerves : The large anterior craral is close outside the artery. 2. Oflfset from the same to the pectineus. 3. Middle cutaneous. 4. Internal cutaneous. 5. Genito-crural. 6. External cutaneous. Dissection on Scarpa's Triangular Space (Illustrations of Dissections). are to be taken away; and the femoral vessels are to be followed down- wards as far as the sartorius muscle. On the outer side of the vessels clean the divisions of the anterior crural nerve, together with the branches of an artery (profunda) whicli are buried in the fat. In removing the fat from beneath the femoral artery, the student is to look for one or two small nerves to the pectineus muscle. This intermuscular space (fig. 195) contains the trunks of the blood- vessels of the thigh, and the anterior crural nerve, with lymphatics and 564 DISSECTION OF THE THIGH. fat. It measures commonly three inches from above down ; but the length varies with the breadth of the sartorius, and the height at which this muscle crosses inwards. The base of the space is at Poupart's ligament ; and the apex is at the meeting of the sartorius with the adductor longus muscle. Towards the surface it is covered by the fascia lata, and by the teo;u- ments with inguinal glands and superficial vessels. The floor slopes to- wards the middle, where it is deepest ; it is constructed externally by the sartorius. A, and by the conjoined psoas and iliacus, b, for about two inches ; and internally by the pectineus and adductor longus muscle, e and F, and between and beneath these near the large vessels, is a small piece of the adductor brevis. The femoral artery runs through the centre of the hollow, and supplies small cutaneous offsets, as well as a large deep branch, the profunda: a small offset (external pudic) is directed from it to the scrotum across the inner boundary. On the inner side of the artery and close to it is placed the femoral vein, which is here joined by the saphenous and profunda branches. About a third of an inch external to the vessel is situate the large anterior crural nerve, which lies deeply at first between the iliacus and psoas, but becomes afterwards more superficial and divides into branches. Deep lymphatics accompany the femoral vessels, and are continued into the iliac glands in the abdomen ; they are joined by the superficial lymphatics. Femoral Artery (fig. 197.) This vessel is a continuation of the ex- ternal iliac, and reaches from the lower of Poupart's ligament to the margin of the opening in the adductor magnus muscle ; at that spot it passes into the ham, and takes the name popliteal. Occupying two-thirds of the thigh, the course of the vessel will be indicated, during rotation outwards of the limb with the knee-joint half bent, by a line drawn from a point midway between the symphysis pubis and the front of the iliac crest, to the inside of the inner condyle of the femur. In the upper part of its course the artery lies rather internal to the head of the femur, and is comparatively superficial, being uncovered by muscle ; but, in the lower part, it is placed along the inner side of the shaft of that bone, and is beneath the sartorius muscle. This difference in its connections allows of a division of the arterial trunk into two por- tions, superficial and deep. The superficial part of the artery (fig. 195, a), which is now laid bare, is contained in Scarpa's triangular space, and is about three inches long. Its position in that hollow may be ascertained by the line before men- tioned. Incased at first in the crural sheath for about two inches, it is covered by the skin and the superficial fascia, and by the fascia lata and some in- guinal glands. At its beginning the artery rests on the psoas muscle ; and it is subsequently placed over tlie pectineus, e, though at some dis- tance from it in this position of the limb, and separated from it by fat, and the profunda and femoral veins. Its companion vein (A) is on the inner side and close to it at the pubes, but is placed behind the artery at the apex of the space. The anterior crural nerve lies on the outer side, being distant about a third of an inch near Poupart's ligament ; and the internal cutaneous branch of the nerve approaches the artery, or lies on it, near the apex of UPPER PART OF FEMORAL VESSELS. 565 the containing space. Crossing beneath the vessels is the nerve of the pectineus Q. Unusual position. Four examples of transference of the main artery of the limb from the front to the back of the thigh have been recorded. In these cases the vessel passed from the pelvis through the great sacro-sciatic notch, and accom- panied the great sciatic nerve to the popliteal space. The branches of the first part of the artery are the superficial epigastric and circumflex iliac, two external pudic, and the deep femoral branch. The cutaneous offsets have been seen (p. 554), with the exception of the following, which lies at first beneath the fascia lata. The inferior external pudic artery (fig. 195, e) arises separately from, or in common with the other pudic branch (superior). It courses inwards over the pectineus muscle to end in the teguments of the scrotum or the labium pudendi, according to the sex, and it perforates the fascia lata at the inner border of the thigh to reach its destination : in the fat it anasto- moses with branches of the superficial perinasal artery. The deep femoral branch (fig. 197, ^) or the profunda^ is the largest offset of the femoral artery, and arises from the outer part of that trunk one to two inches (Quain) below Poupart's ligament. It is consumed in the muscles of the thigh, and its distribution will be afterwards ascertained. In the present dissection it may be seen to lie over the iliacus muscle, where it gives the external circumflex artery to the outer part of tlie thigh ; and then to turn, with a large vein, beneath the trunks of the femoral vessels to the inner side of the limb.^ Variation in origin. The origin of the profunda may approach nearer to Pou- part's ligament until it arrives opposite that band ; or may even go beyond, and be fixed to the external iliac artery (one example, Quain). And the branch may recede farther and farther from the ligament, till it leaves the parent trunk at the distance of four inches from the commencement ; but in this case the circumflex branches usually arise separately from the femoral. In applying a ligature to the femoral artery in the upper part of the thigh, the thread should be placed four inches below Poupart's ligament, in order that the spot chosen may be free from the disturbing influence of so large an ofl'set. Femoral Vein (fig. 195, K). The principal vein of the limb, whilst in the triangular space, has almost the same relative anatomy as the artery : its position to that vessel, however, is not the same througliout. Beneath Poupart's ligament it is on the inner side of the arterial trunk, and on the same level, and is supported on the pubes between the psoas and pectineus muscles ; but it soon winds beneath the artery, and appears on the outer side opposite the upper border of the adductor longus muscle. Occasionally it is inside the artery throughout. In this space it receives the internal saphenous and deep femoral veins, and a small branch (/) with the inferior external pudic artery. DEEP PARTS OF THE FRONT OF THE THIGH. The muscles on the front of the thigh are to be learnt next : they are the sartorius, and the extensor of the knee ; and at the top of the thigh is the small tensor of the fascia lata. Three muscles are combined in the extensor, viz., rectus, vastus externus, and vastus internus. ' Sometimes the term common femoral is applied to the part of the trunk above the origin of the profunda, and the names superficial and deep femoral to the nearly equal parts into which it divides. 666 DISSECTION OF THE THIGH. The external circumflex branch of the profunda artery lies amongst the muscles and supplies them with branches ; and a large nerve, the anterior crural, furnishes offsets to them. Dissection. To proceed with the deep dissection, the limb is to be retained in the same position as before, and the flaps of skin on the front of the thigh are to be thrown aside. The fascia lata i« to be cut along the middle line of the thigh and knee, and to be reflected to each side nearly to the same extent as the skin. Over the knee-joint the student is to note its attachment to the edges of the patella, and its union with a prolongation from the tendon of the extensor muscle to the leg. In raising the inner piece of the fascia the narroAv muscle appearing (sartorius) should be followed to its insertion into the tibia : and to pre- vent its displacement, it should be fixed with stitches along both edges. Care should be taken of the small nerves in contact with the sartorius ; — viz., a plexus beneath it at the middle of the thigh from the saphenous, internal cutaneous, and obturator ; two branches of the internal cutaneous below its middle, — one crossing the surface, and the other lying along the inner edge of the muscle ; and the trunk of the great saphenous escaping from beneath it near the knee, with the patellar branch of the same per- forating it rather higher. Internal to the sartorius some strong muscles (adductors) are inclined downwards from the pelvis to the femur. The student is to lay bare the fore part of those muscles ; and beneath the most superficial (adductor longus), near where it touches the sartorius, he is to seek a branch of the obturator nerve to the plexus before mentioned in the middle of the thigh. On the outer side of the sartorius is the large extensor of the knee. For its dissection the knee is to be bent, to make tense the fibres : and an expansion below from the common tendon to the fascia lata and the knee-joint is not to be removed now, — its arrangement will be noticed after. The little muscle at the upper and outer part of the thigh, — tensor of the fascia lata, is to be cleaned ; and a strip of the fascia, corresponding with its width, should be left along the outer aspect of the thigh. After this slip has been separated, the rest of the fascia on the outer side of the thigh is to be divided by one or two transverse cuts, and is to be followed backwards to its attachment to the femur. The SARTORIUS (fig. 196, ^) is the longest muscle in the body, and extends from the pelvis to the leg. It arches over the front of the thigh, passing from the outer to the inner side of the limb, and lies in a hollow between the extensor on tlie one side, and the adductors on the other. Its origin is tendinous from the upper anterior iliac spinous process of the hip bone, and from about half the interval between this and the infe- rior process. The fibres constitute a ribbon-like muscle, which ends in a thin tendon below the knee, and is inserted into the inner surface of the tibia — mainly into a slight depression by the side of the tubercle for an inch and a half, but also, by its upper edge, as far back as the internal lateral ligament of the knee-joint. The muscle is superficial throughout, and is perforated by some cuta- neous nerves and vessels. Its upper part is oblique, and forms the outer boundary of the triangular space containing the femoral artery : it rests on the following muscles, iliac us, b, rectus, d, and adductor longus, g, as well as on the anterior crural nerve and the femoral vessels. The middle portion is vertical, and lies in a hollow between the vastus internus e, and SARTORIUS MUSCLE 567 the adductor muscles as low as the opening for the femoral artery ; but beyond that aperture, where it bounds the popliteal space, it is [)laced be- tween the vastus with the great adductor in front, and the gracilis, ii, with tlie inner hamstrings behind. The femoral vessels and their accompany- ing nerves are concealed by this portion of the muscle. The lower or tendinous piece, i, rests on the internal lateral ligament of the knee-joint, Fis. 196. Mm A. -cles : Sartorius. B. Iliacus. C. Tensor fasciae latse. D. Rectus femoris. E. Vastus internus. F. Pectineus. G. Adductor longus. H Gracilis. I. Tendon, of Sartorius Vessels : a. Femoral artery. b. Femoral vein. c. Saphenous vein. SCRFACE View of the Front of the Thioh, the Teguments and Fascia being removkd. (Illustrations of Dissections. being superficial to the tendons of the gracilis and semi-tendinosus, and separated from them by a prolongation of tiieir synovial bursa : from its upper border there is an aponeurotic expansion to join that from tlie ex- tensor over the knee; and from its lower border is given another which blends with the fascia of the leg. Below the tendon the great saphenous nerve appears with vessels ; and piercing it is the patellar branch of the same nerve. Action. The tibia and femur being free to move, the muscle bends the 568 DISSECTION OF THE THIGH. knee and hip-joints over which it passes, giving rise to rotation inwards of the tibia ; and makes tense finally the fascia of the thigh. With the limbs fixed, the two muscles will support the pelvis in stand- ing, and will assist in bringing forwards the pelvis in stooping and walking. When standing on one leg the muscle will help to rotate the body, so as to turn the face to the opposite side. Dissection (fig. 197). The sartorius is to be turned aside, or cut through if it is necessary, to follow the remaining part of the femoral artery. Beneath the muscle is an aponeurosis betw^een the adductor and exten- sor muscles ; this is thin above, and when it is divided the internal saphe- nous nerve will come into view. Parallel to the upper part of the saphe- nous nerve, but outside it, is the nerve to the vastus internus muscle, which sends an offset on the surface of the vastus to the knee-joint ; this may be traced now, lest it should be destroyed afterwards. The plexus of nerves on the inner side of the thigh may be more completely dissected in this stage. The femoral vessels and their branches are to be nicely cleaned. Where the femoral artery passes to the back of the limb its small anastomotic b:'anch arises : this branch is to be pursued through the fibres of the vastus internus, and in front of the adductor magnus tendon to the knee ; an off- set of it is to be followed with the saphenous nerve. Tlie aponeurotic covering o\ev the femoral vessels (fig. 197,'') exists only where these are covered by the sartorius. It is thin above, but below it is formed of strong fibres, which are directed transversely between the vastus internus and the tendons of the adductor muscles. Inferiorly the membranous structure ceases at the opening in the adductor magnus by a defined border, beneath which the saphenous nerve and its vessels escape. The deep part of the femoral artery (fig. 197, ^) lies in a hollow be- tween muscles (Hunter's canal) until it reaches the opening in the adduc- tor magnus. Here it is covered by the sartorius muscle and the subjacent aponeurosis, in addition to the integuments and the superficial and deep fasciae. Beneath it are the pectineus, the adductor brevis in part, the adductor longus, and a small piece of the adductor magnus. On the outer side is the vastus internus. External to the artery and close to it is the femoral vein ; and in the integuments oftentimes an offset of the saphenous passes across the line of the arterial trunk. Crossing over the artery from the outer to the inner side is the internal saphenous nerve, which is beneath the aponeurosis before noticed, but is not contained within the areolar sheath of the vessels. Splitting of the artery. Occasionally the femoral artery is split into two below the origin of the profunda. Four examples of this peculiarity have been met with ; but in all, the trunks were blended into one above the opening in the adductor muscle. Branches. One named branch, anastomotic and muscular offsets, spring from this part of the artery. The anastomotic branch (fig. 198, h) (arter. anastomotica magna) arises close to the opening in the adductor muscle, and divides at once into two parts, superficial and deep : — The superficial offset (w) continues with the saphenous nerve to the ^^ lower bo LOWER PART OF FEMORAL VESSELS 569 lower border of the sartorius, and piercing the fascia lata, ramifies in the integuments. The deep branch (/) is concealed in the fibres of the vastus internus, and descends in front of the tendon of the adductor magnus to the inner side of the knee-joint, where it anastomoses witli the articular branches of Fig. 197. 1. Femoral artery. 2. Profunda artery. 3. Internal circumflex. 4. External circumflex. 6. Superficial circumflex iliac and epigas- tric branches. 6. External pudic artery. 7. Aponeurosis over tke lower part of the femoral artery. 8. Anterior crural nerve. 9. Pectineus muscle. 10. Adductor longus. 11. Gracilis. 12. Vastus internus. 1.3.' Kectus femoris. 14. Sartorius cut across. Deep part of the Femoral Artery and its Branches, with Muscles op the Thigh (Quain's Arteries). the popliteal and anterior tibial arteries. A branch passes outwards from it in the substance of the vastus, and forms an arch in front of the lower end of the femur with an offset of the upper external articular artery ; from this loop twigs descend to the joint. Muscular branches. Branches for the supply of the muscles come 670 DISSECTION OF THE THIGH. mostly from the outer side of the femoral artery ; they enter the sartorius, the vastus internus, and the adductor longus. The FEMORAL VEIN Corresponds closely with the femoral artery in its connections with the parts around, and in its branches. Dissection. The femoral artery and vein are to be cut across below the origin of the profunda, and are to be thrown downwards preparatory to the deeper dissection. Afterwards all the fat, and all the veins, are to be carefully removed from amongst the branches of the profunda artery and anterior crural nerve. Unless this dissection is completed, the upper part of the vastus internus will not be prepared for learning. The TENSOR VAGINA FEMORis (fig. 198, ^') occupies the upper third of the thigh, and is the smallest and most external of the outer set of mus- cles. It takes origin from the front of the crest of the hip bone at tlie outer aspect ; from the anterior upper iliac spine, and from part of tlie notch between this and the inferior spine as far as the attachment of tiie sartorius. Its fibres form a fleshy belly about two inches wide, and are inserted into the fascia lata about three inches below, and rather in front of the line of the great trochanter of the femur. At its origin the muscle is situate between the sartorius and the gluteus medius. Beneath it are the ascending offsets of the external circumflex artery ; and a branch of the superior gluteal nerve enters its under surface. A strong sheath of fascia surrounds the muscle. Action. Supposing the limb movable the muscle abducts the thigh, making tense at the same time the fascia lata ; and finally it will help in rotating inwards the femur. When the limb is fixed it will support the pelvis, and assist in balancing the same on the femur in walking. Dissection. After the tensor has been learnt, the slip of fascia extending from it to the knee may be cut through ; and when it is detached from the muscles around, the head of the rectus may be followed upwards to the pelvis. The TRICEPS EXTENSOR of the knee (fig. 197) consists of three fleshy parts or heads, outer (vastus externus), inner (vastus internus), and mid- dle (rectus), which are united below in a common tendon. The RECTUS FEMORIS givcs rise to a fleshy prominence on the front of the thigh (fig. 197, '^). At its origin from the pelvis the muscle consists of two tendinous pieces : one arises from the anterior inferior iliac spinous process ; the other (to be afterwards seen) is fixed into a depression on the back of the hip bone, close above the acetabulum. The fleshy fibres terminate inferiorly in another tendon, which joins the aponeurotic parts of the other two muscles in the common tendon. The rectus is larger at the middle than at the ends ; and its fibres are directed from the centre to the sides, as in a quill, giving rise to that con- dition called penniform. It is subcutaneous, except above where it is overlaid by the sartorius. It conceals branches of the external circumflex artery and anterior crural nerve, and rests on tlie vasti. The U{)per ten- don of the rectus readiest furthest on the anterior surface where the sar- torius touches, whilst the lower tendon is most extensive on the posterior aspect, or towards the subjacent vasti. Dissection. To see the remaining muscles, cut across the rectus near the lower end, and raise it without injuring the branches of vessels and nerves beneath. The muscular mass on the front of the femur is to be divided into two, above, along the situation of some descending vessels and TRICEPS EXTENSOR OF KNEE. 671 fnerves : the part external to the vessels is the vastus externus, and the larjrer mass, internal to them, is the vastus internus. To make out the lower separation of the two, look to the outer aspect of the thigh about half way down, where the long and vertical fibres of the vastus externus descending to their tendon, cross over others (deeper), which are continued obliquely inwards, and belong to the inner vastus. The VASTUS EXTERNUS has a very narrow attachment to the femur in comparison with its size. It takes origin along the upper half of the femur, by a piece from half an inch to an inch thick, which is attached to the root of the neck of the femur, and the fore and outer parts of the root of the great trochanter ; to the line connecting the trochanter with the linea aspera ; and to the upper half of the linea aspera, and the contiguous external intermuscular septum. Interiorly the fibres of the muscle end in an aponeurosis which blends with the tendons of the rectus and vastus internus in the common tendon, and sends a slip to the outer edge of the patella. The muscle is pointed at the upper end ; but enlarged below where it produces tlie prominence on the outer side of the thigh. Its cutaneous surface is aponeurotic above, and is covered by the rectus, tensor vaginae femoris, and gluteus muscles. The deep surface rests on the vastus inter- nus, and receives branches of the external circumflex artery and anterior crural nerve. The VASTUS INTERNUS (fig. 19G, ^) form the large head of the exten- sor.^ The fleshy mass arises from the anterior and two lateral surfaces of the shaft of the femur, except where the vastus externus is attached, and its limits may be thus indicated : Upwards it reaches as far as the ante- rior introchanteric line ; downwards, in the middle, to about two inches from the articular end of the femur ; and laterally to both intermuscular septa. At the lower end of the muscle the fibres terminate in an aponeu- rosis, which blends in the common tendon of insertion, and is attached to the patella lower than the vastus externus. The upper part of the muscular mass is buried beneath the sartorius and rectus muscles ; but the lower part is superficial, and projects more than the vastus externus ; some of the lowest fibres are almost transverse, and will be able to draw inwards the patella. The adductor muscles are almost inseparably joined with this vastus along the attachment to the linea aspera. Dissection. The tendon of the extensor will appear by dividing along the middle line of the patella and knee-joint a thin aponeurotic layer, which is derived from the lower fleshy fibres of the muscle, and covers the joint. On reflecting inwards and outwards that fibrous layer the tendon will be laid bare to its insertion into the tibia. The tendon of the extensor muscles of the leg is common to the rectus, the vastus externus, and vastus internus. It is placed in front of the knee-joint, to wiiich it serves the oflice of an anterior ligament. Wide above where the muscular fibres terminate, it narrows as it descends over the joint, and is inserted inferiorly into the prominence of the tubercle of the tibia, and into the bone below it for an inch ; close to its attachment to the tibia a synovial bursa is beneath it. In it the patella is situate, ' Sometimes the part of the mass, inside a line continued upwards from the inner border of the patella, is named aureus : naturally there is not any separa- tion at that spot. 572 DISSECTION OF THE THIGH. some few scattered aponeurotic fibres passing over the cutaneous surface, but none being continued over the articular surface of the bone. (See Ligament of the Patella.) From the lower part of the muscle a superficial aponeurotic expansion is derived : this prolongation, which is strongest on the inner side, is united with the fascia lata and the other tendinous offisets to form a cap- sule in front of the joint, and is fixed below to the heads of the tibia and fibula. Suhcrureus muscle. Beneath the strong fibres of the vastus, near the knee joint, is a thin layer of pale fibres, which is but a part of the inner vastus, separated from the rest by areolar tissue. Attached to the femur in the lower fourth, and often by an outer and inner slip, it ends in apo- neurotic fibres on the synovial sac of the knee joint. Action. All three heads of the triceps extend the knee joint, when the tibia is movable ; and the rectus can flex the hip joint over which it passes. The fleshy bellies are strong enough to break the patella transversely over the end of the femur, or to rupture sometimes the common tendon. When the tibia is fixed the vasti will bring forwards the femur, and straighten the knee, as in walking or standing ; and the rectus will prop the pelvis on the femur, or assist in moving it forwards in stooping. The subcrureus contracts in extension of the knee, and elevates the synovial membrane above the patella. Intermuscular septa. The processes of the fascia lata, which limit laterally the extensor muscle of the knee, are thus named, and are fixed to the linea aspera and the lines leading to the condyles of the femur. The external septum is the strongest, and reaches from the outer condyle of the femur to the insertion of the gluteus maximus. It is situate between the vastus internus and externus on the one side, and the short head of the biceps on the other, to which it gives origin ; and it is perforated near the outer condyle by the upper external articular vessels and nerve. The inner partition is very thin along the side of the vastus internus ; and its place is supplied by the strong tendon of the adductor magnus be- tween the inner condyle and the linea aspera : the internal articular ves- sels are transmitted through it to the front of the knee joint. The EXTERNAL CIRCUMFLEX ARTERY (fig. 197, *) is the cllicf VCSScl for the supply of the muscles of the front of the thigh. It arises from the outer side of the profunda (deep femoral) artery, but often from the femoral trunk. It is directed outwards through the divisions of the anterior crural nerve, and beneath the sartorius and rectus muscles to the outer part of the thigh, where it ends in branches. Offsets are given from it to the rectus and sartorius ; and its terminal muscular branches consist of ascend- ing, transverse, and descending : — The ascending branch is directed beneath the tensor vaginae femoris to the back of the hip bone, where it anastomoses with the gluteal artery, and supplies the contiguous muscles. The transverse^ the smallest in size, divides into two which perforate the vastus externus, and anastomose w^ith arteries on the back of the thigh. The descending branch is the largest, and ends in pieces which are dis- tributed to the vasti muscles. One considerable branch enters the outer part of the vastus internus, and reaching the knee, anastomoses on this joint with the external articular arteries ; a small ofi*set courses over tlie muscle with a nerve to the joint. The ANTERIOR CRURAL NERVE (fig. 197, ^) of the lumbar plexus (p. ANTERIOR CRURAL NERVE. 573 497) supplies the muscles, and most of the teguments of the front of the thigh, and the integuments of the inner side of the leg. Soon after the trunk of the nerve leaves the abdomen it is flattened, and is divided into superficial and deep parts. A. The superficial part ends in three tegumentary branches : the mid- dle and internal cutaneous of the thigh, and the great saphenous. The middle cutaneous nerve (fig. 192, ^) perforates the fascia lata, some- times also the sartorius, about three inches below Poupart's ligament, and extends to the knee (p. 556). The internal cutaneous nerve (fig. 192, ^) sends two or more small twigs through the fascia lata to the integument of the upper third of the thigh, and then divides in front of the femoral artery, or on the inner side, into the two following branches, anterior and inner. Sometimes these branches arise from the anterior crural trunk at separate spots : — The anterior branch (^) is directed to the inner side of the knee. As far as the middle of the thigh it lies over the sartorious, but it then pierces the fascia lata, and ramifies in the integuments (p. 557.) The inner branch remains beneath the fascia lata as far as the knee (p. 557). Whilst underneath the fascia the nerve lies along the inner border of the sartorius, and joins in a plexus, about the middle of the thigh, with offsets of the obturator and, nearer the knee, with a branch of the internal saphenous nerve. The, internal saphenous nerve (fig. 197) is the largest of the three super- ficial branches. In the thigh the nerve takes the course of the deep blood- vessels, and is continued along their outer side, beneath the aponeurosis covering the same, as far as the opening in the adductor magnus muscle. At that spot the nerve passes from beneath the aponeurosis, and is pro- longed under the sartorius muscle to the upper part of the leg, where it becomes cutaneous (fig. 192, *). It supplies two offsets whilst it is con- tained in the thigh beneath the fascia : — A communicating branch arises about the middle of the thigh, and crosses inwards beneath the sartorius to join in the plexus of the internal cutaneous and obturator, or with the internal cutaneous nearer the knee : this branch is often absent. The patellar branch springs from the nerve near the knee joint, and perforating the sartorius muscle and the fascia lata, ends in the integument over the knee (fig. 192, ^). B. The deep or muscular part of the anterior crural nerve (fig. 197) gives branches to all the muscles of the front of the thigh, except the tensor vaginne femoris ; and it supplies also an offset to one of the adduc- tor muscles, viz., the pectineus. A slender nerve (fig. 195, '^) crosses beneath the femoral artery, and enters the anterior surface of \.\\q pectineus : sometimes there are two. Branches to the sartorius are furnished by the middle, or by the inter- nal cutaneous nerve, whilst it is in contact with that muscle. A nerve enters the under surface of the rectus at the upper part, and divides into branches as it is about to penetrate the fibres. The nerve to the vastus externus separates into two or more branches as it enters the muscle. From one of these an articular filament is con- tinued downwards to the knee joint, which it enters on the anterior aspect. The nerve to the vastus internus (fig. 197) is nearly as large in size as the internal saphenous, in common with which it often arises. To the 574 DISSECTION OF THE THIGH. upper part of the vastus it furnishes one or more branches, and is then continued as far as the middle of the thigh, where it ends in otisets to tlie muscle and the knee joint. Its articular branch is prolonged on or in the vastus, and on the tendon of the adductor magnus to the inner side of the knee joint; and it is dis- tributed over the synovial membrane on the front of the articulation. Tliis small nerve accompanies the deep branch of the anastomotic artery. A branch of nerve to the tensor vagince femoris is derived from the superior gluteal ; it enters the under surface of the muscle, and extends nearly to the lower end. Directions. After the examination of the muscles of the front of the thigh, with their vessels and nerves, the student is to learn the adductor muscles, and the vessels and nerves which belong to them. PARTS OF THE INNER SIDE OF THE THIGH. The muscles in this position are the three adductors, — longus, brevis, and magnus, with the gracilis and pectineus ; these have the following position with respect to one another. Internal to all and the longest, is the gracilis. Superficial to the others, are the pectineus and the adductor longus ; and beneath the last two are the short adductor and the adductor magnus. In connection with the muscles, and supplying them are the profunda artery (of the femoral) and its branches, with the accompanying vein. Tlie obturator nerve lies amongst the adductor muscles, and furnishes branches to them. Dissection. For the preparation of the muscles, the investing fascia and tissue are to be taken away ; and the two superficial adductors are to separated from one another. Let the student be careful of the branches of the obturator nerve in connection with the muscles, viz., those entering the muscular fibres, and one issuing beneath the adductor longus, to join the plexus at the inner side of the thigh. Lastly, should any fat and veins be left with the profunda and its branches they must be removed. The GRACILIS reaches from the pelvis to the tibia (fig. 198, °), and is fleshy and ribbon-like above, but tendinous below. The muscle arises by a thin aponeurosis, two or three inclies in depth, from the pubic boi'der of tlie hip bone close to the margin, viz., opposite the lower half of the sym- {)hysis, and the upper part of the pubic arch. Inferiorly it is inserted by a flat tendon, about one-third of an inch wide, into the inner surface of the tibia, beneath and close to the sartorius. The muscle is superficial throughout. At the upper part of the thigh it is flattened against the adductors brevis and magnus, so as to have its borders directed forwards and backwards; and in the lower third, it inter- venes between the sartorius and semi-membranous muscles, and forms part of the inner boundary of the popliteal space. At its insertion the tendon is nearer the knee than that of the semitendinosus, though at the same depth from the surface, and both lie over the internal lateral liga- ment; and from the tendon an expansion is continued to the fascia of the leg, like the sartorius. A bursa separates the tendon from the ligament, and projects above it to the sartorius. Action. It bends the knee joint if the tibia is not fixed, rotating in ADDUCTOR MUSCLES OF HIP JOINT, Fiff. 198. 575 Deep Dissectton of Muscles : A. Adductor longus, cut. B. Pectineus, cut. c. Gracilis. D. Adductor brevis. E. Adductor magnus. F. Obturator externus. o. Semimembranosus. H. Vastus internus. K. Rectus femoris. li. Tensor fasciae latse. N. Piece of the sartorius. o. Iliacus. p. Psoas. Vessels : a. Femoral artery, and 6, />. Trnnk nf tVio nrnfnn<1« THE Adductor McsciiEs with their Vessels and Nerves. (Illustrations of Dissections.) d. Internal, and e, external circumflex. /. First, g, second, and h, third perforating. i. Muscular and anastomotic of the profunda. Tc. Anastomotic of the femoral, with I, the articular, and n, the cutaneous piece. Nerves : 1. Obturator, joined by the accessory obtu- rator nerve, with 2, the superficial, and 4, the deep part. 3. Cutaneous branch of the obturator. 5. Articular branch to the kee from the deep piece. 6. Anterior crural nerve. 7. Internal saphenous, and 10, its patellar branch, femoral vein. 8. Nerve to the vastus internus, and 9 its 576 DISSECTION OF THE TIirGII. that bone ; and then brings the movable femur towards the middle line with the other adductors. Supposing the foot resting on the ground the gracilis will aid in propping the pelvis on the limb. The PECTiNEus (fig. 196, ^) is the highest of the muscles directed from the pelvis to the inner side of the femur. It has a fleshy origin from the ilio-pectineal line of the hip bone, and from the triangular smooth surface in front of that line; and it is inserted inferiorly by a tendon, about two inches in width, into the femur behind the small trochanter, and into the upper part of the line which extends from that process to the linea aspera. The muscle is twisted, so that the surfaces which are directed forwards and backwards near the pelvis are turned inwards and outwards at the femur. One surface is in contact with the fascia lata; and the opposite touches the obturator muscle and nerve, and the adductor brevis. The pectineus lies between the psoas and the adductor longus ; and the internal circumflex vessels pass between its outer border and the psoas. Action. It adducts the limb and bends the hip-joint. When the femur is fixed it can support the pelvis in standing; or it can draw forwards the pelvis in stooping. The ADDUCTOR LONGUS lies below the pectineus (fig. 196, ^), and is triangular in form, with the apex at the pelvis and the base at the femur. It arises by a narrow tendon from the front of the pubes below the angle of union of the crest and the symphysis ; and it is inserted into the inner edge of the linea aspera. This muscle is situate between the gracilis and the pectineus, and forms part of Scarpa's triangular space. Its anterior surface is covered near the femur by the femoral vessels and the sartorius : the posterior rests on the other two adductors, on part of the obturator nerve, and on the deep femoral artery. Aponeurotic bands connect the tendon of insertion with the adductor magnus and vastus internus. Action. With the femur movable, it will flex the hip-joint, and with the aid of the other adductors will carry inwards the limb, so as to cross the thigh bones. In walking it helps the other adductors to project the limb. With the femur fixed, the muscle props and tilts forwards the pelvis. Dissection. The adductor brevis muscle, with the obturator nerve and the profunda vessels, will be arrived at by reflecting the two last muscles. On cutting through the pectineus near the pubes, and throwing it down, the dissector may find occasionally the small accessory nerve of the obtu- rator which turns beneath the outer border; if this is present, its branches to the hip joint and the obturator nerve are to be traced out. The adductor longus is then to be divided near its origin, and raised with care, so as not to destroy the branches of the obturator nerve beneath ; its tendon is to be detached from that of the adductor magnus beneath it, to see the branches of the profunda artery. Now the adductor brevis will be laid bare. A part of the obturator nerve crosses over this muscle to the femoral artery, and sends an ofl*set to the plexus at the inner side of the thigh : a deeper part of the same nerve lies beneath this adductor. The muscle should be separated from the subjacent adductor magnus, where the lower branch of the nerve with an artery issues. In this last ste^) of the dissection the student should trace on and in the fibres of the adductor magnus a slender articular branch of the obturator nerve to the knee. OBTURATOR NERVE AND BRANCHES. 577 The accessory obturator nerv^ (Sclimidt) is derived from the trunk of the obturator, near the lumbar plexus (p. 497), and passes from the abdo- men over the brim of the pelvis. In the thigh it turns beneath the pecti- neus, and joins the superficial part of the obturator nerve ; it supplies an offset to the hip-joint with the articular artery, and occasionally one to the under surface of the pectineus. The ADDUCTOR BREVis (fig. 198, ^) has a thin fleshy and aponeurotic attachment, about two inches in depth, to the front of the hip-bone with the gracilis. The muscle arises from the pubic border of the bone close to and outside the gracilis, reaching upwards as high as the adductor lon- gus, and not quite so low as tlie gracilis. It is inserted, behind the pecti- neus, into all the line leading from the lineaaspera to the small trochanter. In front of the muscle are the pectineus and the adductor longus, with the superficial piece of the obturator nerve, and the profunda artery ; but it is gradually uncovered by the adductor longus below, and the contiguous borders of the two are side by side at their insertion into the femur. Be- hind the muscle is the adductor magnus, with the deep piece of the obtu- rator nerve and a branch of the inner circumflex artery. In contact with the upper border is the obturator externus, f, and the internal circumflex artery passes between the two. Action. This muscle adducts the limb with slight flexion of the hip- joint, like the pectineus. And if it acts from the femur it will balance and move forwards the pelvis. The OBTURATOR NERVE (fig. 198, M is a branch of the lumbar plexus (p. 497), and supplies the adductor muscles of the thigh, as well as the hip and knee joints. The nerve issues from the pelvis through the aper- ture in the upper part of the thyroid foramen ; and it divides in that open- ing into two pieces, which are named superficial and deep from their posi- tion w4th respect to the adductor brevis muscle. A. The superficial part (^) of the nerve is directed over the adductor brevis, but beneath the pectineus and the adductor longus, to the femoral artery, on which it is distributed ; at the lower border of the last muscle it furnishes an offset or two to join in a plexus with the internal cutaneous and saphenous nerves (p. 573), and supply the teguments.-* Near the pelvis or in the a[)erture of exit, this piece of the nerve sends outwards an articular twig to the hip joint with the joint-artery. Muscular branches are furnished to the adductor longus, the adductor brevis, and the gracilis. B. The deep part (*) of the obturator nerve pierces the fibres of the ex- ternal obturator muscle, and continuing beneath the adductor brevis is con- sumed chiefly in the adductor magnus. The following offsets are supplied by it : — Muscular branches enter the obturator externus as the nerve pierces it ; others are furnished to the large, and sometimes to the short adductor. A slender articular branch (fig. 198, ^) enters the fibres of the adductor magnus, and passes through it near the linea aspera to reach the popliteal ' This small nerve is often absent; it was found only four or live times in nine or ten bodies which were examined by its discoverer. The name given to it by Schmidt refers to this irregularity, viz., nerv. ad obturatorem accessorius incon- stans. Commentarius de Nervis Lumbalibus. 2 In some bodies the superficial part of the nerve is of large size, and has a dis- tribution similar to that of the inner branch of the internal cutaneous nerve, whose place it takes : in such instances it joins freely in the plexus. 37 .578 DISSECTION OF THE THIGH. artery, by which it is conducted to tlie b«ick of the knee-joint : its termi- nation is seen in the dissection of the popliteal space. Dissection. To prepare the profunda artery and its branches, supposing the veins and the fat removed, it will be requisite to follow backwards the internal circumflex artery above the upper border of the adductor brevis, and to trace the perforating branches to the apertures in the adductors near the femur. The PROFUNDA (fig. 198, c) is the chief muscular artery of the thigh, and arises from the femoral about one inch and a half below Poupart's ligament (p. 565). At its origin the vessel is placed on the outer side of the parent trunk ; but it is soon directed inwards beneath the femoral ves- sels to the inner side of the femur, and ends at the lower third of the thigh in a small branch that pierces the adductor magnus. Where the vessel lies in the triangular space of the thigh it rests on the iliacus muscle. But on the inner side of the femur it is parallel to the femoral artery, though deeper in position ; and it is placed first over the pectineus and adductor brevis, and thence to its termination between the adductors longus and magnus. Its branches are numerous to the surrounding muscles on the front and back of the thigh, and maintain free anastomoses with other vessels of the thigh and leg ; through these communications the blood finds its way to the lower p«rt of the limb when the tube of the chief artery is obliterated either above or below the origin of the profunda. The named branches are these : — The external circumjiex artery (fig. 198, e) has been described in the dissection of the muscles of the front of the thigh (p. 572). The internal circumflex branch (fig. 198, d) arises from the inner and posterior part of the profunda, and turns backwards between the psoas and pectineus, but above the adductor brevis and magnus. Opposite the small trochanter it ends in two branches, which will be seen in the dissection of the buttock (p. 590). It supplies the undermentioned offsets to the inner side of the thigh : — An articular artery may enter the hip joint through the notch in the acetabulum. At the border of the adductor brevis two muscular branches arise : one ascends to the obturator and the superficial adductor muscles; the other, which is larger, descends with the deep piece of the obturator nerve be- neath the adductor brevis, and ends in this and the largest adductor. The perforating branches, three in number, pierce the tendons of some of the adductor muscles close to the linea aspera of the femur : they sup- ply muscles on the back of the thigh, and wind round tlie thigh-bone to end in the vasti. The^rs^ (/) begins opposite the lower border of the pectineus, and per- forates the short and large adductors. The second branch {g) arises below the middle of the adductor brevis, and passes through the same muscles as the preceding: from \i 21, nutritious vessel is supplied to the shaft of the femur. The third artery (A) springs from the deep femoral trunk below the ad- ductor brevis, and is transmitted through the adductor magnus. The terminal branch of the profunda (fourth perforating) pierces the adductor magnus near the aperture for the femoral artery. Muscular or anastomotic branches (/) to the back of the thigh (three or four in number) pass through the adductor magnus at some distance ADDUCTOR MAGNUS MUSCLE. 579 from tlie linea aspera, and end in a chain of anastomoses in the ham- strings. Tlie PROFUNDA VEIN results from the union of the different branches corresponding with the offsets of its companion artery. It accompanies closely the artery of the same name, to which it is superficial, and ends above in the femoral vein. Dissection, To bring into view the remaining muscles, viz., adductor magnus, obturator externus, and the psoas and iliacus insertion, the ad- ductor brevis is to be cut through near the pelvis, and to be thrown down. Then tlie investing layer of fascia and areolar tissue is to be removed from each muscle. After the adductor magnus has been learnt, it will be needful to detach a few of the upper fibres to examine the obturator externus. The ADDUCTOR MAGNUS (fig. 128, ^) is narrow at the pelvis, and wide at the femur. It is triangular in form, with its base directed upwards, one side being attached to the femur, and the other free at the inner part of the thigh. The muscle arises along the pubic arch of the innominate bone outside the other adductors, reaching from the symphysis to the lower part of the ischial tuberosity. The anterior fibres diverge from their origin, being horizontal above but more oblique below, and are inserted (from above down) into the line from the great trochanter to the linea aspera ; into the linea aspera ; and into the line leading from that crest of bone to the inner condyle for about an inch. The posterior fibres from the ischial tuberosity are vertical in direction, and end at the lower third of the thigh in a tendon, which is inserted into the inner condyle of the femur, and is connected by a fibrous expansion to the inner condyloid ridge. The muscle consists of two parts, which differ in their characters. The anterior one, thin and fleshy, forms a septum between the other adductors and the muscles on the back of the thigh ; but the posterior piece, partly fleshy and partly tendinous, constitutes the inner thick margin of the muscle. On the anterior surface are tiie other two adductors and the pec- tineus, with the obturator nerve and the profunda artery. The posterior surface touches tlie ham-string muscles and the great sciatic nerve. In contact with the ujjper border are the obturator externus and the quadra- tus femoris, with the internal circumflex vessels ; and along the inner border lie the gracilis and the sartorius. At its attachment to the femur the muscle is closely united with the other adductors, particularly the adduc- tor longus, and is there pierced by apertures for the passage of the femoral and perforating arteries. Action. This muscle is used as an adductor, but chiefly as a projector forwards of the femur in walking : in the last oflfice it receives help from the other adductors internally, and from the gluteus medius and minimus externally. The femur being fixed it will act powerfully in keeping the pelvis erect on the head of the thigh bone. The opening in the adductor for the transmission of tlie femoral vessels into the popliteal space is tendinous at the anterior, but flesliy at the pos- terior aspect. It is situate at the point of junction of the middle with the lower third of the thigh, and is larger than is necessary for tlie passage of the vessels. On the outside it is bounded by the vastus internus ; and on the inside by the tendon of the adductor magnus, with some fibres added from the tendon of the long adductor. 680 DISSECTION OF THE THIGH. The PSOAS and iliacus (fig. 198) arise separately in the abdomen (p. 493), but are united in the thigh — tlie conjoined portion of the muscles coming beneath Ponpart's ligament. The psoas, f, is inserted by tendon into the small trochanter of the femur : and the fleshy iliacus, o, joins partly the tendon of the psoas, tut the rest of its fibres are fixed into a special triangular surface of bone in front of and below that trochanter. Beneath the ligament the muscles occupy the interval between the ilio- pectineal eminence and the anterior s^uperior iliac spinous process — the iliacus resting on a small bursa ; and below the pelvis the mass covers the capsule of the hip joint, and a larger intervening bursa. On the front of the psoas is the femoral artery, and between the two muscles lies the an- terior crural nerve. The pectineus and the internal circumflex vessels are contiguous to the inner border ; and the sartorius and vastus internus touch the outer edge. Action. These muscles act as flexors of the hip joint, and their use is given with the description of the part in the abdomen (p. 493). The OBTURATOR EXTERNUS (fig. 198, ^) is triangular in form, with the base at the pelvis and the apex at the femur. The fibres of the muscle take origin from the outer surface of the obturator membrane for the an- terior half ; and from the anterior half or more of the bony circumference of the thyroid foramen — the attachment being an inch wide opposite the symphysis pubis. The fibres are directed obliquely backw^ards to be in- serted by a tendon into the pit at the root of the great trochanter. This muscle is concealed by the pectineus, and adductor brevis and magnus. It covers the obturator membrane and vessels, and is pierced by part of the obturator nerve. As it winds back it is in contact with the inner and lower parts of the hip joint. The insertion of the muscle will be seen in the dissection of the Buttock. Action, The muscle is an external rotator of the thigh : and its action will be given in full with the other muscles of the same grou}) in the Buttock. Dissection By detaching a small part of the obturator muscle from the pelvis, the branches of the artery and nerve of the same name will be seen amongst its fibres. A better view will be obtained if the dissec- tion of the vessel and nerve is deferred till after the limb is detached. The obturator artery is a branch of the internal iliac (p. 515), and enters the thigh through the upper part of the thyroid foramen. In the aperture the artery divides into two pieces, which form a circle beneath the muscle around the obturator membrane : — The upper branch extends along the inner half of the membrane ; and the lower, perforating the membrane below the level of the other, turns downwards and forms a circle by uniting with the upper branch. An articular twig to the hip-joint is supplied fi-om the lower branch. Muscular oflTsets of tlie artery are furnished to the obturator muscles, and some small twigs reach the upper part of the adductors. Branches of nerve to the external obturator muscle come from the deep portion of the obturator trunk, and [)erforate the membrane with the lower branch of the artery. CUTANEOUS NERVES OVER GLUTEUS. 681 Section II. THE BUTTOCK. OR THE GLUTEAL REGION. Directions. Both this Section and the following one are to be completed bj the student in the time appointed for the body to lie in the prone position. Position. During the dissection of the back of the thigh the body is placed with the face down ; and the pelvis is to be raised by blocks, until the lower limbs hang almost vertically over the end of the dissecting table. When the body is turned, the points of bone marking posteriorly the limit between the thigh and the abdomen can be better ascertained. Dissection. The integument is to be raised from the buttock by means of the following incisions : One is to be made along the iliac crest of the hip bone, and is to be continued in the middle line of the sacrum to the tip of the coccyx. Another is to be begun where the first terminates, and is to be carried outwards across the thigh till it is about six inches below the great trochanter. The flap of skin thus marked out is to be thrown down. Many of the cutaneous nerves of this region will be found in the fat along the line of the iliac crest. Tiius in front, but rather below the crest, are branches of the external cutaneous, if tliese have not been cut in the dissection of the thigh. Crossing the crest towards the fore part is a large offset of the last dorsal nerve ; and usually farther back, but close to the bone, a smaller branch from the ilio-hypogastric nerve. In a line with the outer border of the erector spinas, are two or three branches of the lumbar nerves. By the side of the sarcum and coccyx two or three offsets of the sacral nerves are to be looked for beneath the fat. The remaining cutaneous nerves are derived from the small sciatic, and must be sought beneath the fat along the line of the lower incision, where they come from underneath the gluteus maximus. A few turn ui)wards over that muscle ; the rest are directed down the thigh, and one (inferior pudendal) bends below the ischial tuberosity to reach the perinjcal space. Cutaneous arteries accompany all the nerves, and will serve as guides to their situation. Cutaneous Nerves (fig. 199). The nerves distributed in the integu- ments of the buttock are small but numerous, and are derived from the spinal nerves (posterior primary pieces) ; from branches of the lumbar and sacral plexuses ; and from the last dorsal nerve. Branches of the lumbar Qierves (^). The offsets of the posterior primary pieces of the lumbar nerves (p. 367) are two or three in number, and cross the crest of the hip bone near the anterior edge of the erector spin* : they ramify in the integuments of the middle of the buttock, and some branches may be traced nearly to the trochanter major. The branches of the sacral nerves Q) perforate the gluteus maximus near the sacrum and coccyx, and are then directed outwards for a siiort distance in the integuments over the muscle. These offsets are usually two in number : the largest is opposite the lower end of the sacrum, and the other by the side of the coccyx. The last dorsal nerve (^) supplies the buttock by means of its lateral 582 DISSECTION OF THE BUTTOCK, cutaneous branch (p. 416). This offset peiforates the muscles of the abdo- men, and crosses tlie anterior part of the iliac crest to be distributed over the fore part of the gluteal region, as low as the great troclianter. Nerves of the lumbar plexus. Parts of two nerves of tlie lumbar ])lexus (p. 496), viz. ilio-hypogastric and external cutaneous, are si)ent in the integuments of this region. The iliac branch of the ilio-hypogastric (') crosses the iliac crest in front of the branches from the lumbar nerves, lying generally in a groove in the bone, and extends only a short distance below the crest. Fig. 199. A. Glutens inaximus muscle, with the gluteus medius projecting above it. a. Continuation of small sciatic ar- tery along the back of the thigh. Nerves and vessels, most of them cut from the teguments : — 1. Small sciatic nerve — the trunk. 2. Its cutaneous thigh branches ; & 3. Inferior pudendal. 4. Small sciatic offsets in the peri- njeum. 5. Cutaneous of the sacral. 6. Offsets of the lumbar nerves. 7. Ilio-hypogastric 8. Branch of the last dorsal. SuPKRFiciAii View op the Bpttock of the Lkft Side (Illustrations of Dissections). Offsets of the external cutaneous nerve of the thigh bend backwards to tiie integuments above the great trochanter, and cross the ramifications of the last dorsal nerve. Small sciatic (*). This nerve of the sacral plexus (p. 518) sends super- ficial branches to the buttock. Its cutaneous offsets appear along the lower border of the gluteus maximus, accompanied by superficial branches THE GLUTEUS MAXIMUS. 583 of the sciatic artery : two or three ascend round the edge of the muscle, and are lost in the integuments of the lower part of the buttock ; tlie remain- ing branches (^) descend to the thigh, and will be afterwards noticed on it. Dissection. The thin and unimportant deep fascia of this region may be disregarded, in order that the great gluteal muscle, which is the most difficult in the body to clean, may be well displayed. Supposing the stu- dent desirous to lay bare the muscle, let him turn aside the cutaneous nerves, and adduct and rotate inwards the limb to make tense the muscu- lar fibres. Having cut through the fat and fascia from the origin to the insertion, let him carry the scalpel along one bundle of fibres at a time in the direction of a line from the sacrum to the femur, imtil all the coarse fasciculi are cleaned. If the student has a right limb, the dissection may be begun at the upper border ; but if a left limb, at the lower margin of the muscle. The fasia of the buttock is a prolongation of that enveloping the thigh, and is fixed to the crest of the hip bone, and to the sacrum and coccyx. It is much thicker in front of, than on the gluteus maximus, and gives attachment anteriorly to the gluteus medius which it covers. At the edge of the gluteus maximus, the fascia splits to incase the muscle. The GLUTEUS MAXIMUS (fig. 199, ^^ is the most superficial muscle of the buttock, and reaches from the pelvis to the upper part of the femur. Its origin from the pelvis is partly connected with bone and partly with aponeurosis: Thus, the muscle is attached, from above down, to the pos- terior third of the iliac crest, and to a special impression on the hip bone below it; next, to the aponeurosis covering the multifidus spinse muscle; then to the back of the lowest piece of the sacrum, and the back of the coccyx ; and lastly to the great sacro-sciatic ligament. From this exten- sive origin the fibres are directed outwards to their insertion: About two- thirds of the upper fibres, and a few of the lowest, end in the fascia lata of the outer part of the thigh : and the remainder are fixed for three inches into the lower part of the line leading from the linea aspera to the great trochanter of the femur. The gluteus forms the prominence of the buttock, and resembles the deltoid muscle of the arm in the situation, and in the coarseness of its tex- ture. Its cutaneous surface is covered by the common teguments and in- vesting fascia of the limb, and by the superficial nerves and vessels. The parts in contact with the under surface will be seen when the muscle is cut through. The upper border overlays the gluteus medius. And the lower edge, which is longer and thicker than the upper, forms the fold of the nates, and bounds posteriorly the perinjeal space ; beneath the lower border the ham-string muscles and the sciatic vessels and nerves issue. Action. With the femur hanging the muscle extends tlie hip-joint by putting back that bone, and abducts and rotates out the limb. When the limb is fixed, and the body is raised from a sitting into a standing posture, the gluteus acts as an extensor of the articulation by moving back the pelvis. In standing both muscles assist in keeping the pelvis balanced on its props ; and in rising from stooping they are the active agents in bringing upright the pelvis. When the body is supported on one leg the muscle can draw tlie sacrum towards the femur, so as to turn the face to the oppo- site side. Dissection (fig. 200). The gluteus maximus is to be cut across near the pelvis, and without injury to the subjacent sacro-sciatic ligament to 684 DISSECTION OF THE BUTTOCK.. whicli the lower fibres are closely joined. The depth of the muscle will be ascertained by the fascia and some vessels beneath it. When this in- termuscular layer is arrived at, the outer part of the gluteus is to be thrown towards its insertion, and the sciatic artery and nerves are to be detached from the under surface, though the branches of the gluteal ves- sels entering the muscle must be cut. The loose fat is to be taken away from the hollow between the pelvis and the trochanter, without injuring the vessels and nerves ; and the several muscles are to be cleaned, the fibres of each being made tense at the time of its dissection by rotating the lemur. Tlie vessels, nerves, and muscles, which ar-e to be defined, may be ascertained by referring to the enumeration below of the parts beneath the gluteus. In removing the areolar tissue from the ischial tuberosity and the great trochanter, the bursa on each prominence of bone will be observed. Lastly the origin of the muscle is to be removed ; and the sacral nerves are to be dissected out of the gluteus, and to be followed to the surface of the great sacro-sciatic ligament, where they will be afterwards seen. Parts beneath the gluteus (fig. 200). At its origin the gluteus maximus rests on the pelvis, and conceals part of the hip bone, sacrum, and coccyx, also the ischial tuberosity with the origin of the hamstring muscles, l, and the great sacro-sciatic ligament, k. At its insertion it covers the upper end of the femur, with the great trochanter, and the origin of the vastus externus, i. Between the muscle and each prominence of bone, viz. the tuberosity and the trochanter, is a large, loose synovial membrane; and between it and the vastus externus is another synovial sac. In the hollow between the j^elvis and the femur the muscle conceals, from above downwards, the undermentioned parts : — First, a portion of the gluteus medius,. a ; and below it the pyriformis, b, with the superficial branch (a) of the gluteal vessels between the two. Coming from beneath the pyriformis are the sciatic vessels (&)» and the large and small sciatic nerves (*, ^), which descend to the thigh between the great trochanter and the ischial tuberosity ; and internal to the sciatic iU'e the pudic vessels and nerve (c?, ^)^ and the nerve to the obturator internus muscle (*) with its vessels, which are directed inwards through the small sacro-sciatic notch. Still lower down is the tendon of the obturator internus muscle, d, with a fleshy fasciculus — the gemellus (c and k)— above and below it. Next comes the thin quadratus femoris muscle, g, with the upper part of tlie adductor magnus, ii : at the upper border of the quadratus is the tendon of the obturator externus, f ; and at the lower bonier, between it and the adductor^ issues one of the terminal branches of the internal circumflex artery (c) with its veins. Dissection. Tracing back the oflTsets of the sacral nerves which perfo- rate the gluteus, and removing a fibrous stratum which covers them, the looped arrangement of the first three nerves on the great sacro-sciatic ligament will appear. Finally the nerves may be followed inwards beneath the multifidus spinae to the posterior sacral foramina. Sacral nerves. The external pieces of tlie posterior primary branches of the first three sacrjU nerves, after passing outwards beneath the multi- fidus spina? (p. 372), are joined by loops on the surface of the great sacro- sciatic ligament (fig. 120). Two or three cutaneous offsets are derived from this intercommunica- tion, and pierce the fibres of the gluteus maximus to be distributed on the surface (p. o81). GLUTEUS MEDIUS 585 The GLUTEUS MEDIUS (fig. 200, ^) is triangular in form, with its base at the innominate bone, and apex at the femur. It arises from the outer surface of the hip bone between the crest and the superior curved line, Fig. 200. Second View of the Dissection of the Buttock (Illustrations of Dissectious) Muscles : A. Gluteus medius. B. Pyrifoimis. 0. Upper gemellus. D, Obturator iuteruus. K. Gemellus inferior. F. Obturator externus. Q. Quadratus femoris. H. Adductor magnua. 1. Vastus externus. J. Gluteus maximua, cut. K. Great sacro sciatic ligament. L. Hamstring muscles. Arteries : a. Gluteal. b. Sciatic. c. Internal circumflex. d. Pudic. e. Anastomotic branch of sciatic. /. First perforating. Nerves : 1. Last dorsal. 2. Upper gluteal. 3. Small sciatic. 4. Nerve to the obturator internus. 5. Pudic. 6. Great sciatic. 7. Inferior pudendal. 8. Cutaneous of the thigh of small sciatic. 9. Muscular branch of great sciatic. except behind where there is a surface of bone free from muscular fibres ; and many superficial fibres come from the strong fascia covering the ante- rior part of the muscle. The fibres converge to a tendon, which is inserted 586 DISSECTION OF THE BUTTOCK. into an impression across the outer surface of the great trochanter, extend- ing from the tip behind to the root in front. Tlie superficial surface is concealed in part by the gluteus maximus ; and the deep is in contact with the gluteus minimus, and the gluteal ves- sels and nerve. The anterior border lies over tlie gluteus minimus, and is in contact with the tensor of the fascia lata. The posterior is contigu- ous to the pyriformis, only the gluteal vessels intervening. A small bursa is interposed between the tendon of insertion and the trochanter. Action. The wliole muscle abducts the hanging femur; and the ante- Of? ' rior fibres rotate in the limb. In walking it is combined with the adduc- tors in moving forwards the femur. Both limbs resting on the ground the muscles assist in fixing the pelvis. In standing on one leg this gluteus will aid in balancing the pelvis on the top of the femur. Dissectio7i. When the gluteus medius is detached from the pelvis, and partly separated from the gluteus minimus beneath, the gluteal vessels and nerve will come into view. The two chief branches of the artery — one being near the iliac crest, and the other lower down — are to be traced through the fleshy fibres as the reflection of the gluteus is proceeded with ; and the main part of the nerve is to be followed at the same time to the tensor vagina femoris muscle. The branches of the artery and nerve to the gluteus medius will be cut in removing that muscle. The gluteal artery (fig. 200, a) is the largest branch of the internal iliac (p. 513), and issues from the pelvis above the pyriform muscle. On the dorsum of the hip bone it ends in offsets which supply the gluteal muscles and the bone. Its named branches are superficial and deep: — The superjlcial branch supplies offsets to the integuments, and some deeper twigs over the sacrum ; it ends in the gluteus maximus, which it penetrates on the under surface. The deep branch (fig. 201, a) is the continuation of the artery, and subdivides into two pieces which run between the two smaller glutei. One {b) (superior) courses along the origin of the gluteus minimus (supplying mostly the medius) to the front of the iliac crest, where it anastomoses with the ascending branch of the external circumflex artery. The other portion (c) (inferior) is directed forwards over the middle of the smallest gluteal muscle, with the nerve, towards the anterior lower iliac spine where it enters the tensor of the fascia lata, and communicates with the external circumflex branch (p. 572) : many offsets are furnished to the gluteus minimus, and some pierce that muscle to supply the hip joint. Vein. The companion vein with the artery enters the pelvis, and ends in the internal iliac vein. The superior gluteal nerve (fig. 201, ^) is a branch of the lumbo-sacral cord (p. 495-C). It accompanies the gluteal artery, and divides into two branches for the supply of the two smallest gluteal muscles: its lowest branch terminates anteriorly in the tensor vagiuic femoris, b. The GLUTEUS MINIMUS (fig. 201, c) is triangular in shape, and arises from the dorsum of the hip bone between the superior and inferior curved lines, extending backwards as far as the middle of the hip joint. Its ten- don is inserted into an impression along the fore part of the great trochan- ter, where it is united inferiorly with the gluteus medius: some fibres are attached to the capsule of the hip joint. One surface is in contact with the gluteus medius, and the gluteal ves- sels and nerve; the other with the hip bone, the hip joint, and the outer GLUTEUS MINIMUS AND PYRIFORMIS. 687 head of the rectus femoris muscle. The anterior border lies by the side of the other gluteus; and the posterior is covered by the pyriformis muscle. A bursa is placed between the tendon and the bone. Action. It acts as an abductor and rotator out of the femur when this bone is hanging; and in walking, it and the medius will be employed in bringing forwards the limb. Both legs being fixed, the muscles are used in balancing the pelvis. In standing on one leg the gluteus pitches the pelvis over the supporting limb with the preceding muscle. Dissection. Cut through the smallest gluteus muscle near the innomi- nate bone, and define the tendinous part of the rectus femoris underneath it, close above the hip joint. Whilst detaching the gluteus from the parts underneath, the student cannot fail to notice the connection between its tendon and the capsule of tlie joint. The deep vessels to the articulation may be observed and followed as the muscle is removed. Tlife outer head of the rectus femoris is a tendon as wide as the little finger, and about two inches long, which is fixed into the groove above the margin of the acetabulum. In front it joins the other tendinous piece of the rectus, which is attached to the anterior inferior iliac spine ; and balow, it is connected with the capsule of the hip joint. The PYRIFORMIS (fig. 200, ^) arises in the pelvis from the front of the sacrum (p. 542), and leaves that cavity through the great sacro-sciatic notch. Outside the pelvis it ends in a rounded tendon, which is inserted into the upper edge of the great trochanter, between the two smaller glutei. As the muscle passes through the sacro-sciatic notch it divides that space into two parts — the upper giving passage to the gluteal vessels and nerve, and the lower transmitting the sciatic and pudic vessels and the sacral plexus. Its upper border is contiguous to the gluteus medius, and its lower, to the gemellus superior. Like the other rotator muscles in this situation, it is covered by the gluteus maximus, and by the gluteus medius at the insertion ; it rests on the gluteus minimus, which separates it from the hip joint. Its tendon is united by fibrous tissue to that of the obturator and gemelli. Action. The use of this and the other external rotators is altered by the position of the femur. If that bone hangs the pyriformis rotates it out ; but if the hip joint is bent the muscle abducts the limb from its fellow. Both limbs being fixed the muscles balance the pelvis, and help to make the trunk erect after stooping to the ground. In standing on one leg, besides assisting to support the trunk, the pyriformis turns the face to the opposite side. Dissection (fig. 201). The pyriformis may be cut across and raised towards the sacrum, to allow tlie dissector to follow upwards the sciatic and pudic vessels, and to trace the accompanying nerves to tlieir origin in the lower part of the sacral plexus. Some small nerves to the obturator internus (*), the gemellus superior ('), and the hip joint, are to be sought in the fat at the lower part of the plexus. A branch to the inferior gemellus and the quadratus (*) will be found by raising tlie trunk of the great sciatic nerve ; but it will be fol- lowed to its termination after the muscles it supplies have been seen. 688 DISSECTION OF THE BUTTOCK. Sciatic and Pudic Vessels. The vessels on the back of the pelvis, below the piriformis muscle, are branches of the internal iliac (p. 513). The sciatic artery (fig. 200, b) supplies the buttock below the gluteal. After escaping from the pelvis below the pyriformis, it descends with the small sciatic nerve over the gemelli and obturator muscles, as far as the lower border of the gluteus maximus : here the artery gives off many branches with the superficial offsets of its companion nerve ; and mucli reduced in size, it is continued with that nerve along the back of the thigh. In this course it furnishes the following named branches : — a. The coccygeal branchy arising close to the pelvis, perforates the great sacro-sciatic ligament and the gluteus maximus, and ramifies in this muscle, and on the back of the sacrum and coccyx. b. The branch to the great sciatic nerve (comes nervi ischiadici) is very slender, and entering the nerve near the pelvis, ramifies in it along the thigh. c. Muscular branches enter the gluteus maximus, the upper gemellus, and obturator internus ; and by means of a branch to the quadratus, which passes with the nerve of the same name beneath the gemelli and obturator internus, it gives offsets to the hip joint and the inferior gemellus. d. Anastomotic branch (fig. 200, e). Varying in size this artery is directed outwards to the root of the great trochanter, where it anastomoses with the gluteal and internal circumflex. The pudic artery (fig. 200, c?) belongs to the perina3um and the genital organs; it is smaller than the sciatic, internal to which it lies. Only the small part of the vessel which winds over the ischial spine is seen on the back of the pelvis, for it enters the perinieal space through the small sacro-sciatic notch, and is there distributed (p. 390). It supplies a small branch over the back of the sacrum, which anasto- moses with the gluteal and sciatic vessels ; and a twig from it accompanies the nerve to the obturator internus muscle. The veins with the sciatic and pudic arteries receive contributing twigs corresponding with the branches of those arteries at the back of the pelvis, and open into the internal iliac vein. Sciatic and Pudic Nerves. The nerves appearing at the back of the pelvis, below the pyriformis, are branches of the sacral plexus to the lower limb (p. 518) ; they are furnished mostly to parts beyond the gluteal region, but a few are distributed to the muscles at the back of the pelvis. The small sciatic (fig. 200, ^) is a cutaneous nerve of the back of the thigh, for it supplies only one muscle of the buttock. It springs from the lower part of the sacral plexus, generally by two pieces, and takes the course of the sciatic artery as far as the lower border of the great gluteus, where it gives many cutaneous branches : much diminished in size at that spot, the nerve is continued along the back of the thigh beneath the fascia, and ends below the knee in the integuments of the back of the leg. The branches which are distributed to, or near the buttock, are muscular and cutaneous : — The muscular branches (inferior gluteal) enter the under surface of the gluteus maximus near the lower border. The cutaneous branches are directed upwards and downwards at the border of the gluteus : — The ascending set (fig. 199) are distributed in the fat over the lower third of the muscle. THE SUPERIOR AND INFERIOR GEMELLUS. 589 The descending set (fig. 199, '^) supply the integuments of the upper third of the thigh at the inner and posterior aspects. One of these branches ('), which is larger than the 'others, is distributed to the genital organs, and is named inferior pudendal (p. 394) ; as it courses to the perina3um, it turns b^elow the ischial tuberosity, and perforates the fascia lata at the inner part of the thigh to end in the scrotum. The ffi^eat sciatic (fig. 200, ^) is the largest nerve in the body. It is the source of all the muscular, aud most of the cutaneous branches dis- tributed to the limb beyond the knee, as well as of the muscular branches at the back of the thigh. At its origin it appears to be a prolongation of the sacral plexus. It is directed through the buttock to the posterior part of the thigh, and rests on the external rotator muscles below the pyriformis. Commonly it does not supply any branch to the buttock, but it may give origin to one or two filaments to the hip joint. Frequently the nerve is divided into two large trunks at its origin, and one of them pierces the fibres of the pyriformis muscle. The pudic nerve (fig. 200, °) winds over the small sacro-sciatic liga- ment by the side of its companion artery, and is distributed with this vessel to the perinaium and the genital organs (p. 391). No branch is supplied to the buttock. Muscular branches of the sacral plexus are furnished to the gluteus maximus, and to the external rotators except the obturator externus. Branches of gluteus. One or more branches of the plexus enter the top of the gluteus maximus (fig. 200). Two branches of the pyriformis enter the under surface, and are learnt with the sacral plexus in the pelvis. The nerve to the obturator internus (fig. 201, ^) arises from the upper part of the plexus, and is directed to its muscle through the small sacro- sciatic notch with the pudic nerve : its termination is seen in the dissec- tion of the pelvis. The nerve to the superior gemellus (fig. 201, '') is a very small twig, and arises separately from the following : it enters the inner end of the muscle on the superficial surface. The 7ierve to the inferior gemellus and the quadratus (fig. 201, ^) is a slender branch, which passes with a companion artery beneatli the gemelli and the obturator internus, to end in the two muscles from which it re- ceives its designation. This nerve will be seen more fully in a subse- quent dissection, when articular filaments from it to the hip-joint may be recognized. Dissection. To see the remaining small rotator muscles, hook aside the great sciatic nerve, and take away the branches of the sciatic artery if it is necessary. In cleaning these muscles the limb should be rotated in- wards. The gemelli are to be separated from the tendon of tlie obturator internus. The SUPERIOR GEMELLUS (fig. 200, ^) is the highest of the two mus- cular slips along the sides of the tendon of the obturator muscle. Inter- nally it is attached to the outer and lower part of the ischial spine, and externally it is inserted with the obturator into the great trochanter. Oftentimes the muscle is absent. The INFERIOR GEMELLUS (fig. 200, ^) is larger than its fellow. Its origin is connected with the upper part of the ischial tuberosity, along the lower edge or lip of the hollow for the obturator internus muscle ; 590 DISSECTION OF THE BUTTOCK. and its insertion is the same as that of the obturator tendon. Tliis mus- cle is phiced between the obturator internus and quadratus, but near the femur the tendon of the obturator externus comes into contact with its lower border. Action. These small fleshy slips seem to be but accessory pieces of origin to the internal obturator, with which they combine in use. The OBTURATOR INTERNUS (fig. 200, ^) ariscs from the innominate bone inside the pelvis (p. 543), and passes to the exterior through the small sacro-sciatic notch. The tendon of the muscle is directed outwards over the hip-joint, and is inserted with the gemelli into the upper part of the great trochanter, in front of the pyriformis, as well as into the con- tiguous portion of the neck of the femur. Outside the pelvis the obturator is mostly tendinous, and is embraced by the gemelli muscles in the following way: near the pelvis the gemelli meet beneath, but near the trochanter they cover the tendon. Beneath the obturator is a synovial sac. Crossing the muscle are the large and small sciatic nerves and the sciatic vessels ; and covering the whole is the gluteus maximus. On cutting through the tendon and raising tlie inner end, it will be found divided into three or four pieces as it turns over the margin of the pelvis (fig. 201, ") ; at this spot the pelvis is marked by ridges of fibro-cartilase, which correspond with the intervals between the tendons, and the surfaces are lubricated by a synovial membrane. Action. Acting from the hinder border of the pelvis round which it turns, it rotates out or abducts the femur according as this bone may be hanging or raised. It will erect the pelvis after stooping, and will balance the same in standing; and it will rotate to the opposite side the trunk supported on one limb. The QUADRATUS FEMORis (fig. 200, ^) has the form expressed by its name, and is situate between the inferior gemellus and the adductor mag- nus. Internally it arises from the outer border of the tuber ischii for two inches, along the origin of the semi-membranosus and adductor mag- nus ; externally it is inserted into a tubercle in the posterior intertrochan- teric ridge, and slightly into the neck of the femur ; and into a line on the upper end of the bone for about two inches above the attachment of the great adductor. By one surface it is in contact with the sciatic vessels and nerves, and the gluteus. By the other it rests on the obturator externus, the internal circumflex vessels, and its small nerve and vessels. Between its lower border and the adductor magnus one of the terminal branches of the inter- nal circumflex artery issues. Between it and the small trochanter is a bursa, which is common also to the upper part of the adductor magnus. Action. Though the muscle has but slight power, it will be associated with the other muscles on the back of the pelvis in rotation out of the pendent femur, and in abduction of the femur when tiie hip-joint is bent. And its femoral attachment being fixed, it will help in supporting the pelvis; or it will turn the face to the opposite side, the body being sup- ported on one limb. Dissection (fig. 201). The quadratus and the gemelli muscles may be now cut across, in order that their small nerve and artery, the ending of the internal circumflex artery, and the obturator externus may be dis- sected out. The internal circrnnflex branch (fig. 201,/) of the profunda artery (p. 578) divides finally into two parts. One {(j) ascends beneath the quad- QUADRATUS AND OBTURATOR EXTERNUS 591 ratus (in this position of the body) to the pit of the trochanter, where it anastomoses with the gluteal and sciatic arteries, and supplies the bone. The other (//) passes between the quadratus and adductor magnus to the hamstring muscles, and communicates with a branch of the profunda artery. The OBTURATOR EXTERNUS (fig. 201,^) has been dissected at its origin in the front of the thigh (p. 580). The part of the muscle now laid bare, winds below the hip-joint, and ascends to be inserted into the pit at the root of the great trochanter. Muscles. A. GJuteus maximus, cut. B. Tensor fasciae latse. c. Gluteus minimus. D. Gluteus medius, cut. F. Pyiiformis. G. Gemellus superior H. Obturator intei nus, cut. I. Gemellus inferior. K. Quadratus femoris, cut. L. Obturator exteruus. N. Adductor magnus. 0. Hamstrings. p. Great sacro-sciatic liga- ment. Arteries, a. Gluteal. h. Its upper and, and c, its lower piece. d. Sciatic. e. Pudic. /. Internal circumflex ; g, its ascending, and h, its transverse offset. i. First perforating. It. External circumflex. Nerves. 1. Superior gluteal. 2. Sacral. 3. Small sciatic, cut. 4. Pudic. 5. Nerve to obturator inter- nus. 6. Nerve to quadratus and inferior gemellus. 7. Nerve to upper gemellus. 8. Large sciatic nerve. Third View of thk Dissection of the Buttock (Illustrations of Dissections), On the back of the pelvis the obturator externus is covered by the quad- ratus, except near the femur where the upper border is in contact with the inferior gemellus. As it turns back to its insertion it supports the hip-joint. Action. Like the other muscles of the same group it rotates out the hanging limb ; but it differs from them in having the same action even when the hip-joint is bent. "With the limb fixed, Theile supposes it to help in bending the hip-joint 592 DISSECTION OF THE THIGH. in stooping, instead of extending it and raising the trunk like the other external rotator muscles. The sacko-sciatic ligaments pass from the innominate bone to the sacrum and the coccyx ; they are two in number, and are named large and small. The large ov posterior ligament (fig. 201, ^) is attached internally to the posterior part of the hip bone, and to the side of the sacrum and coccyx ; and externally it is inserted into an impression on the inner and anterior part of the ischial tuberosity, sending upwards a prolongation along the pubic arch. It is wide next the sacrum, but is contracted towards the middle, and is expanded again at the tuberosity. On the cutaneous sur- face are the branches of the sacral nerves ; and the gluteus maximus con- ceals and takes origin from it. Branches of the gluteal and sciatic arteries perforate it. The small ligament will be seen on dividing the other near the hip bone. At the sacrum and coccyx it is united with the large band, but at the opposite end it is inserted into the ischial spine. It is less strong than the superficial ligament, by wMiich it is concealed ; and it rests on the coccy- geus muscle. By their attachments these ligaments convert the large sacro-sciatic notch of the dried pelvis into two apertures or foramina. Between their insertion into the spine and tuberosity of the innominate bone, is the small sacro-sciatic foramen, which contains the internal obturator muscle with its nerve and vessels, and the pudic vessels and nerve. And above the smaller ligament is the large sacro-sciatic foramen, which gives passage to the pyriformis muscle, with the gluteal vessels and the superior gluteal nerve above it, and tlie sciatic and pudic vessels and the sacral plexus below it. Section III. THE BACK OF THE THIGH. Directions. The ham or the popliteal space may be taken after the buttock, in order that it may be seen in a less disturbed state than if it was dissected after the examination of the muscles at the back of the thigh. When this space has been learnt the student will return to the dissection of the thigh. • Position. The limb is to remain in the same position as in the dissec- tion of the buttock. Dissection (fig. 202). To remove the skin from the popliteal region let an incision be made behind the knee for the distance of six inches above, and four inches below the joint. At eacii extremity of the longitudinal cut make a transverse incision, and raise the skin in two flaps, the one being turned outwards and the other inwards. In the fat arc some small cutaneous nerves and vessels, viz., one or two twigs in the middle line of the limb from the small sciatic nerve and artery beneath the fascia ; and some otfsets of the internal cutaneous nerve towards the inner part. After the subcutaneous fat is removed, the special fascia of the limb will be brought into view. ANATOMY OF POPLITEAL SPACE. 598 Fascia lata. Where this fascia, covers the popliteal space it is strength- ened by transverse fibres, particularly on the outer side ; and it is connected laterally with the tendons bounding that interval. The short saphenous vein perforates it sometimes opposite the knee, but usually at a spot lower down. Dissection (fig. 202). The fascia over the ham is now to be removed without injuring the small sciatic nerve and artery, and the short saphe- nous vein, which are close beneath it. A large quantity of fat may be next taken out of the space, but without injury to the several small vessels and nerves in it. In cleaning the space the student will come upon the large internal popliteal nerve in tlie middle line ; and nearer the outer side, on the ex- ternal popliteal. Both nerves give branches ; and the numerous offsets of the inner will be recognized more certainly by tracing them from above down along the trunk of the nerve, than by proceeding in the opposite direction ; in fat bodies the two small nerves from the inner popliteal trunk to the knee joint are difficult to find. Under cover of the outer boundary, and deep in the space, is an articular nerve from the external popliteal, which sometimes arises from the great sciatic. In the bottom of the space are the popliteal vessels, the vein being more superficial than the artery. The student is to seek an articular branch (superior), on each side, close above the condyle of the femur; and to clean numerous otlier branches of the vessels to the muscles around, espe- cially to those of the leg. On the upper part of the artery, the branch of nerve from the obturator to the knee joint is to be found : and on the sides of the artery are three or four lymphatic glands in the fat. After the ham has been cleaned, the sartorius and the gracilis are to be replaced in their natural position on the inner side. The POPLITEAL SPACE, or the ham (fig. 202), is the hollow behind the knee : it allows of the free flexion of the joint, and contains the large ves- sels of the limb. When dissected, this interval has the form of a lozenge, and extends upwards along one-third of the femur, and downwards along one-sixth of the tibia ; but in the natural condition of the parts the sides are approximated by the fascia of the limb, and the space is limited, ap- parently, almost to the region of the joint. This hollow is situate between the muscles on the back of the limb ; and the lateral boundaries are therefore formed by the muscles of the thigh (hamstrings), and leg. Thus, on the outer side, is the biceps muscle (^) as far as the joint ; and the plantaris and the external head of the gastrocne- mius (^) beyond that spot. On the inner side, as low as the articulation, are the semimembranosus (*) and semitendinosus (^) muscles, with the gra- cilis and sartorius between them and the femur ; and beyond the joint is the inner head of the gastrocnemius C). The upper point of the ham is limited by the apposition of the inner and outer hamstrings ; and at the lower point the heads of the gastrocnemius touch each other. Stretched acrross the cavity are the fascia lata and teguments. Forming the deep boundary, or the floor, are the following parts — the posterior sur- face of the femur included between the lines to the condyles, the posterior ligament of the knee-joint, and part of the popliteus muscle with the upper end of the tibia. The popliteal space is widest opposite the femoral condyles, where the muscles are most drawn to the sides ; and is deepest above the articular 38 594 DISSECTION OF THE THIGH. end of the femur. Above and below it communicates, benetith tlie muscles, with the back of the thigh and leg. In the hollow are contained the popliteal vessels with their branches, and the endingof the external saphenous vein ; the popliteal trunks of the great sciatic nerve, and some of their branches ; together with lymphatic glands, and a large quantity of fat. The small sciatic nerve and its vessels are placed superficially in the ham ; and a branch of the obturator nerve lies on the artery in the bottom of the space. I'he POPLITEAL ARTERY (fig. 202, ^) is the continuation of the femoral, and reaches from the opening in the adductor magnus to the lower border of the popliteus muscle, where it terminates by bifurcating into the anterior and posterior tibial vessels. A portion of the artery lies in the ham, and is uncovered by muscle ; buttlie rest is beneath the gastrocne- miu«, and beyond the limits of the popliteal space as above defined. The description of the artery may be divided therefore into two parts, corresponding with this difference in the connections. In the ham the vessel is inclined obliquely from the inner side of the limb to the interval between the condyles of the femur ; and is then directed along the middle of the space over the knee-joint. As far as the inner condyle the artery is overlaid by the belly of the semi- membranosus muscle ; but thence onwards it is situate between the heads of the gastrocne- mius, and is covered only by the fascia lata and the integuments. Beneath it is the femur with the posterior ligament of the knee-joint. In contact with the vessel, and somewhat on the outer side at first, lies the popliteal vein, so that, on looking into the space, the arterial trunk is almost covered ; but in the interval between the heads of the gastrocnemius, the vein and its branches conceal altogether the artery. Below the knee the short saphenous vein (fig. 203, i), and the muscular branches of the artery, are laid over the popliteal trunk. More superficial than the large vessels, and slightly external to them in position, is placed the internal poi)liteal nerve, which with its branches lies over the artery, like tlie vein, between the heads of the gastrocnemius. In the bottom of the hollow the small obtura- tor nerve runs on the artery to the joint. Dissection. To see the deep part of the artery the inner head of the gastrocnemius should be cut through, and raised from the subjacent parts. On removing the areolar tissue tlie vessels and nerves will appear. The lower articular branches of the vessels and nerve are now brou^jht into View of the Popliteal Space Quaia's Arteries). . Popliteal vessels. I. Internal popliteal nerve. ;. External popliteal nerve. . Semimembranosus muscle. I. Semitendinosus muscle. 1, Biceps muscle. Inner and outer heads of the gastrocnemius muscle. The superficial vein on the gastroc- nemius is the short saphenous, \vhich enters the popliteal. 7. 8, POPLITEAL ARTEHY AND BRANCHES. 595 view ; — the inner artery is below the head of the tibia, and the outer higher up between the tibia and fibula, each with a vein, and the first has a companion nerve. Beyond the ham. Whilst the artery is beneath the gastrocnemius (fig. 208) it sinks deeply into the limb ; here it is crossed by a small muscle — the plantaris c, and the ending is concealed by the soleus b. It rests on the po[)liteus muscle. Both the companion vein and the internal popliteal nerve change their position to the artery, and gradually cross over it, so as to lie on its inner side at the lower border of the popliteus. Sometimes the artery is divided as high as the back of the knee joint ; and then the anterior tibial artery may lie beneath the popliteus muscle. Branches (fig. 203) are furnished by the artery to the surrounding mus- cles, and to the articulation ; — those that belong to the joint are five in number, and are called articular, viz., two superior, inner and outer; two inferior, also inner and outer ; and a central or azygos branch. a. The 7nusctilar branches are upper and lower. The upper set, three or four in number, arise above the knee, and end in the semi-membranosus and biceps muscles, communicating with the perforating and muscular branches of the profunda. The lower set (sural) are furnished to the muscles of the calf, viz., gastrocnemius, soleus, and plantaris. b. A superficial or cutaneous branch arises near the knee joint, and ac- companies the external saphenous nerve over the muscles of the leg to end in the teguments (fig. 203). c. The superior articular arteries arise from the popliteal trunk, one from the inner and one from the outer side, above the condyles of the femur ; they are directed almost transversely beneath the hamstring mus- cles, and turn around the bone to the front of the joint. The external one (¥) perforates the intermuscular septum, and divides in the substance cf the vastus internus. Some of the branches end in that muscle, and anastomose with the external circumflex (of the profunda) : others descend to the joint ; and one offset forms an arch across the fore part of the bone with the anastomotic artery. The internal artery (/), oftentimes very small, winds beneath the ten- don of the adductor magnus, and terminates in the vastus internus ; it supplies this and the knee joint, and communicates with the anastomotic artery. d. The inferior articular branches (fig. 208) lie beneath the gastro- cnemius, but are not on the same level on opposite sides of the limb ; for the inner one descends below the head of the tibia, whilst the outer one is placed above the fibula. Each lies beneath the lateral ligament of its own side. The external hv^iwoh. (c) supplies she outer side of the knee joint, anas- tomosing with the other vessels on the articulation, and with the recurrent branch of the anterior tibial artery : it sends an offset beneath the liga- ment of the patella to join a twig from the lower internal branch. The internal artery (6) ascends at the anterior border of the internal lateral ligament, and after taking its share in the free anastomoses over the joint, ends in offsets for the articulation and the head of the tibia. e. The azygos branch enters the back of the joint through the posterior ligament, and is distributed to the ligamentous structures, the fat, and the synovial menibrane of the interior. 596 DISSECTION OF THE THIGH. The POPLITEAL VEIN (fig. 203, h) originates in the union of the vence comites of the anterior and posterior tibial vessels, and has the same ex- tent and connections as the artery it accompanies. At the lower border of the popliteus muscle the vein is internal to the arterial trunk ; between the heads of the gastrocnemius it is superficial to that vessel ; and thence to the opening in the adductor magnus it lies to the outer side, and close to the artery. It is joined by branches corresponding with those of the artery, as well as by the short saphenous vein (fig. 203). The POPLITEAL NERVES (fig. 202) are the two large trunks derived from the division of the great sciatic in the thigh ; they are named inter- nal and external from their relative position. In the popliteal space each furnishes cutaneous and articular offsets, but only the inner one supplies branches to muscles. The INTERNAL POLITEAL NERVE (^) is larger than the external, and occupies the middle of the ham : its connections are similar to those of the artery, that is to say, it is partly superficial and partly covered by the gas- trocnemius. Like the vessel it extends through the back of the leg, and retains the name popliteal only to the lower border of the popliteus mus- cle. Its position to the vessels has been already noticed. The branches arising from it here are the following : — a. Two small articular twigs (fig. 203, *) are furnished to the knee joint with the vessels. One which accompanies the lower internal articu- lar artery to the fore part of the articulation is the largest ; and another takes the same course as the azygos artery, and enters the back of the joint with it. b. Muscular branches arise from the nerve between the heads of the gastrocnemius. One supplies both heads of the gastrocnemius and the phintaris. Another descends beneatli the gastrocnemius, and enters the cutaneous surface of the soleus. And a third penetrates the popliteus at the under aspect, after turning round the lower border. c. The €xter7ial saphejious nerve (fig. 207,^) (ram. communicans tibialis) is the largest branch, and is a cutaneous offset to the leg and foot. It lies on the surface of the gastrocnemius, but beneath the fascia, as far as the middle of the leg, where it becomes cutaneous, and will be afterwards seen. The EXTERNAL POPLITEAL NERVE (fig. 202, ') (peroneal) lies along the outer boundary of the ham as far as the knee joint ; at that level it leaves the space and follows the edge of the biceps muscle for two inches, till it is below the head of the fibula. There it enters the fibres of the peroneus longus, and divides beneath that muscle into three — musculo- cutaneous, anterior tibial, and recurrent articular. Its branches wiiilst in the popliteal space are cutaneous and articular. a. The articular nerve, arising high in the space, runs with tlie upper external artery to the outer side of the knee, where it sends a twig along the lower articular artery : both enter the joint. b. The peroneal communicating branch (fig. 207, *) (ram. communi- cans fibularis) joins the external saphenous branch of the internal popli- teal about the middle of the leg. It soon becomes cutaneous, and offsets are given by it to the back of the leg. c. One or two cutaneous nerves are furnished by the extei-nal [)Opliteal to the integument on the outer side of the leg in the upper half. The articular branch of the obturator nerve (fig. 203, ') perforates the adductor magnus, and is conducted by the popliteal artery to the back of I UAMSTRING MUSCLES. 5J7 the knee joint. After supplying filaments to the vessels, the nerve enters the articulation through the posterior ligament. The lymphatic glands of the popliteal space are situate around the large arterial trunk. Two or three are ranged on the sides ; whilst one is superficial to, and another beneath the vessel : they are joined by the deep lymphatic vessels, and by the superficial set with the saphenous vein. THE BACK OF THE THIGH. Dissection (fig. 203). Now the popliteal space has been examined, the student may proceed with the dissection of the back of the thigh. The piece of skin between the buttock and the popliteal space should be di- vided, and reflected to the sides. In the fat on the sides of the limb fine offsets of the internal and external cutaneous nerves of the front of the thigh may be found ; and along the middle line some filaments from the small sciatic nerve pierce the fascia. Remove the deep fascia of the limb, taking care of the small sciatic nerve and its artery. Lastly, clean the hamstring muscles ; trace out tlie perforating arteries to the front of the thigh, and clean the branches of the great sciatic nerve and profunda artery to the muscles. Muscles. The muscles behind the femur act mainly as flexors of the knee joint. They extend from the pelvis to the bones of the leg, and are named hamstrings from their cord-like appearance on the sides of the ham : they are three in number, viz., biceps, semitendinosus, and semimembra- nosus. The first of these lies on the outer, and the others on the inner side of the popliteal space. The BICEPS (fig. 203, '^) has two heads of origin, long and short, which are attached to the pelvis and the femur. The long head arises from an impression on the back of the ischial tuberosity, in common with the semitendinosus muscle. The short head is fixed to the femur below the gluteus maximus, viz., to all the linea aspera, to nearly the whole of the line leading inferiorly to the outer condyle, and the external intermuscular septum. The fibres end inferiorly in a tendon, which is inserted into two prominences on tlie head of the fibula by slips which embrace the exter- nal lateral ligament ; and a slight piece is prolonged to the head of the tibia. The muscle is superficial, except at the origin, where it is covered by the gluteus : it rests on the upper part of the semimembranosus, and on the great sciatic nerve and the adductor magnus muscle. On the inner side is the semitendinosus as far as the ham. Its tendon gives offsets to the deep fascia of the limb. Action. It can bend the knee if the leg-bones are not fixed, and after- wards rotate out the tibia; and the long head, which passes upwards beyond the femur, will extend the bent hip joint when the knee is straight. The leg being supported on the ground, the long head will assist in balancing and erecting the pelvis ; and the short head will draw down the femur so as to bend the knee in stooping. The SEMITENDINOSUS (fig. 203, ^) is a slender muscle and receives its name from appearance. It arises from the tuberosity of the hip bone with the long head of the biceps, and by fleshy fibres from the tendon of that muscle. Inferiorly it is inserted into the inner surface of the tibia, close below the gracilis, and for a similar extent. Tills muscle, like the biceps, is partly covered by the gluteus maximus. 698 DISSECTION OF THE THIGH About its middle a tendinous intersection may be observed. It rests on the semimembranosus, and on the internal lateral ligament of the knee- joint. The outer border is in contact with the biceps tvs far as tlio i)opli- Fiff. 203. Muscles : A. Gluteus maxiraus, cut below, and partly raised. B. Quadratus femoris. c. Adductor magnus. r>. Biceps. E. Semitendinosus. p. Semimembranosus. G. Outer, and H. Inner head of the gastrocnemius. Arteries : a. Small sciatic, cut. 6. Ending of internal circumflex to the hamstrings, c. First, d, second, and e, third perforating of profiinda. /. Muscular branch of profunda. g. Popliteal tr'iuk. li. Popliteal vein. i. Short saphenous vein. k. Upper external, and I, upper internal articular artery. Nerves : 1. Small sciatic. 2. Large sciatic. 3. Branch to hamstrings from large sciatic. 4. External popliteal ; and . 5. Communicating peroneal. 7. Articular branch of obturator to knee. 8. Internal popliteal. 9. Articular branch to knee of the internal popliteal. 10. Short saphenous. Dlssection of thb Back op the Thioh (Illustrations of Dissections). teal space. As the tendon turns forwards to its insertion, an expansion is continued from it to the fascia of the leg; and it is attached, with the gracilis, below the level of the tubercle of the tibia, the two being separated from the tendon of the sartorius by a bursa (p. 567). Action. If the leg is movable the muscle bends the knee ; and con- tinuing to contract, rotates towards the tibia. Supposing the knee-joint straight but tlie hip-joint bent, the femur can be depressed, and the hip extended by the semitendinosus and the other hamstrings. vShould the limbs be fixed on the ground, the muscle will assist in balancing the pelvis, or in erecting the trunk from a stooping posture. The SP:MiMKMiiKANOSU8 muscle (fig. 203, *") is tendinous at botli ends, and its name is given from the membraniform appearance of the upper BRANCHES OF PROFUNDA ARTERY. 599 tendon. The muscle is attached above to the highest impression on the back of the tuber ischii, above and external to the semitendinosus and biceps ; and it is inserted below into the hinder and inner part of the head of the tibia. The muscle is thick and fleshy inferiorly, where- it bounds the popliteal space. On it lies the semitendinosus, which is lodged in a hollow in the upper tendon; and beneath it is the adductor magnus. Along the outer border lie the great sciatic, and internal popliteal nerves. Between its tendon and the inner head of the gastrocnemius is a large bursa. The insertion of the muscle will be dissected with the knee-joint. Action. This hamstring is united with the preceding in its action, for it bends the knee and rotates in the tibia ; and with the knee straight it will limit flexion of the hip, or extend this joint after the femur has been carried forwards. When the foot rests on the ground, the semimembranosus acts altogether on the pelvis. The GREAT SCIATIC NERVE (fig. 203, ^) lics on the adductor magnus muscle below the buttock, and divides it into the two popliteal nerves about the middle of the thigh, though its point of bifurcation may be car- ried upwards as far as the pelvis. In this extent the nerve lies along the outer border of the semimembranosus, and is crossed by the long head of the biceps. Branches. At the upper part of the thigh it supplies large branches to the flexor muscles, and a small one to the adductor magnus. Small sciatic nerve (fig. 203,^). Between the gluteus maximus and the ham this small nerve is close beneath the fascia ; but it becomes cuta- neous below the knee, and accompanies the external saphenous vein for a short distance. Small cutaneous filaments pierce the fascia of the thigh ; and the largest of these arises near the popliteal space. Dissection. To see the posterior surface of the adductor magnus, and the branches of the perforating and muscular arteries, the hamstring muscles must be detached from the hip bone and thrown down ; and the branches of arteries and nerves they receive are to be dissected out with care. All the parts are to be cleaned. Adductor magnus muscle (fig. 203, ^). At its posterior aspect the large adductor is altogether fleshy, even at the opening for the femoral artery ; and the fibres from the pubic arch appear to form a part almost distinct from those connected with the tuberosity of the hip bone. In contact with this surface are the hamstring muscles and the great sciatic nerve. Ending of the perforating arteries (fig. 203, c, c?, e). These branches of the profunda appear through the adductor magnus close to the femur, and are directed out through the short head of the biceps and the outer intermuscular septum to the vasti muscles ; but as the first branch is placed higher than the attachment of the biceps, it pierces the gluteus maximus in its course. In the vasti they anastomose together, and with the descending branches of the external circumflex artery. Muscular branches are furnished by the perforating arteries to the heads of the biceps ; and a cutaneous off*set is given by each to the tegu- ments of the outer part of the thigh, along the line of the outer inter- muscular septum. 600 DISSECTION OF THE THIGH Fig. 204. Muscular branches of the profunda (fig. 203,/) })ierce the adductor niagnus internal to the preceding, and at some distance from the lemur. Three or four in number, the highest appears about five inches from the pelvis, and the rest in a line at intervals of about two inches from one another : they are distributed to the hamstring muscles, especially the semimembranosus, and communicate below with offsets of the popliteal -trunk. The HIP-JOINT (fig. 204). This articulation is a ball and socket joint, the head of the femur being received into the acetabulum or the cup- shaped hollow of the innominate bone. Connecting the bones are the fol- lowing ligaments : — one to deepen the receiving cavity, which is named cotyloid ; another between the articular surfaces of the bones — the inter- articular ; and a capsule around all. Dissection. The muscles are to be taken away from the back of the hip-joint, and the upper and lower attachments of the capsular ligament are to be especially cleared from areolar tissue. Next, the front of the joint should be cleaned and examined in the same manner, with the body turned over for a short time, if this change in position does not interfere with the other dissec- tions. In the capsule itself the stu- dent has to define a wide thick part in front, and a transverse band near the neck of the femur behind. The capsular ligament (fig. 204) is a thick fibrous case, which is strong enough to check the movements of the joint. Its up- per margin is attached to the circumfererence of the acetabu- lum at a short distance from the edge, as well as to a transverse ligamentous band over the notch at the inner side of the cavity. Its lower margin is inserted in front into the anterior intertro- chanteric line (fig. 204) ; behind, by a very thin piece, into the neck of the femur about a finger's breadth from the small trochanter and the posterior intertrochan- teric line (fig. 205); and above, into the neck, near the great tro- chanter. The capsule differs much in strength, and in the arrangement of the fibres at the fore and hinder surfaces. On the front it is strengthened by a wide layer of longitudinal fibres (fig. 204, a, 6, c). The central portion — the ilio-femoral ligament (a), is fixed above by a narrow piece to the lower anterior iliac spinous pro- cess, and below where it widens, into the anterior intertrochanteric line. By its strength it can arrest extension of the joint ; and the femur being FOKE PART OF THE CAPSULE OF THE IIlP-JOINT. a. Ilio-femoral ligament. b. Pubio-femoral edge or band. c. Ilio-trochauteric band. LIGAMENTS OF HIP JOINT. 601 fixed, it will prop the pelvis. The outer edge (e) (ilio-trochanteric band) extends from the hip bone opposite the outer head of the rectus, to the upper and fore part of the great trochanter and neck of the femur; its use is to check adduction of the femur. The inner edge (b) (pubio- femoral band) is attached superiorly to the prominent pubic portion of the hip bone inside the acetabulum, and inferiorly to a roughened surface at the lower part of the neck of the femur on a level with, and in front of, the small trochanter : this band controls the abductory movement of the joint. Hinder Part of thk Hip-Joint Capsule. a. Longitudinal fibres. 6. Transverse band. Thiu piece attached to the neck of the femur about half way down. At the back of the capsule close to the neck of the femur is a band of transverse fibres (fig. 205, b), about as wide as the little finger, which arches like a collar over the neck of the bone. By its lower edge it is united to the cervix femoris by a thin layer (c) of fibrous tissue and syno- vial membrane ; at the upper edge it is joined by the longitudinal capsular fibres (a). It gives insertion to the longitudinal fibres of the capsule, and prevents that restriction of the swinging movement which would result from their insertion into the hinder part of the neck. Posteriorly the joint is covered by the external rotator muscles ; and anteriorly by the psoas and iliacus, a bursa being between it and them. Above is the gluteus minimus, whose tendon is united with the upper and outer band of the capsule ; and below^ is the obturator externus. Dissection (fig. 206). The capsular ligament is to be now divided over the prominence of the head of the femur, and this bone being disarticu- lated but not detached, the cotyloid and interarticular ligaments inside it will appear. The interarticular or round ligament is attached to the acetabulum by 602 DISSECTION OF THE THIGH. two pieces ; and to bring these into view, the synovial membrane and are- ohir tissue must be removed. Tlie transverse ligament over the notch is also to be defined. The cotyloid ligament (fig. 191, y) is a narrow band of fibro-cartilage, which is fixed to the margin of the acetabulum, and is prolonged across the notch on the inner side, so as to form part of the transverse ligament. Its fibres are not continued around the acetabulum, but are fixed to the margin of the cavity, and cross one another in the band. It is thickest at its attachment to the bone, and becomes gradually thinner towards the iree margin, where it is applied to the head of the femur. This ligament fills up the hollows in the rim of the acetabulum, and deepens the socket for the femur in the same manner as the glenoid liga- ment increases the surface for the reception of the head of the humerus. The transverse ligament (fig. 191, K) is a firm but narrow band, which reaches across the upper part of the notch at the inner side of the aceta- bulum. It consists partly of deep special fibres {h) which are attached to the margins of the notch ; and partly of a superficial bundle from the cotyloid ligament (y). Beneath it is an aperture by which vessels and nerves enter the acetabulum to supply the synovial membrane, and the fat in the bottom of that hollow. The inter articular or round ligament (fig. 206, h) (ligam. teres) is a slight band about an inch long, connecting the femur with the innominate bone. One extremity is roundish, and is inserted into the pit in the head of the femur. The other is flattened, and divides into two parts opposite the transverse ligament. The anterior piece (r) (pubic) is attached with the transverse ligament to the pubic edge of the notch. The posterior part (c?) C ischial) is inserted behind the transverse ligament into the ischial border of the cotyloid notch. Dissection. To see its condition in the different movements of the articu- lation, it should be examined in a joint in which the capsule is entire, and the bottom of the acetabulum has been cut out with a chisel inside the pelvis. When the joint is in the extendad state, the ligament is generally lax, the two end attachments being near each other ; but if the femur is ad- ducted, the ischial part of the ligament is rendered tight because the head of the femur rises. In flexion of the joint the ligament is tighter than in extension, as the femoral insertion is removed from the acetabular ; and if, in the bent state, the femur be rotated out or adducted, the round ligament will be most stretched. A synovial membrane lines the capsular ligament, and. is continued along it to the acetabulum and the head of the femur. In the bottom of the cotyloid cavity it is reflected over the fat in that situation ; and it sur- rounds the ligamentum teres. Dissection. To see the surface of the acetabulum the lower limb is to be separated from the trunk by dividing the interarticular ligament, and by cutting through any parts that connect it to the pelvis : at this stage the pelvic attachments of the round ligament can be better seen. Surfaces of hone. The articular surfaces of the bones are not completely covered with cartilage. MOVEMENTS OF HIP JOINT 60S In the head of the femur is a pit into which the round ligament is in- serted. The acetabulum is coated with cartilage at its circumference, except opposite the notch, and touches the head of the femur by this part : the articular surface is deep above, but gradually decreases towards the notch. Within the cartilage and close to the notch, is a mass of fat (fig. 191, /) covering about one third of the area of the cotyloid cavity, which constitutes the gland of Plavers : it communicates with the fat of the thigh beneath the transverse ligament. Movement. In this ball and socket joint there are the same kinds of movement as in the shoulder, viz., flexion and exten- sion, abduction and adduction, circumduction, and rotation. Flexion and extension. In the swinging movement flexion is freer than extension, the thigh being capable of such elevation as to touch the belly. During swinging the head of the femur revolves in the bottom of the acetabulum, rotating around a line corresponding with the axis of the head and neck ; and the rapidity and extent of tlie move- ments do not endanger the secu- rity of the joint, the head of the bone not having any tendency to escape. In flexion, the back of the capsule and the ilio-trochanteric band are put on the stretch ; and in extension, the strong ilio and pubio-femoral bands are tightened. In abduction and adduction the femur is removed from, or brought towards the middle line of the body. Of the two, abduction is the most extensive, because the limb may soon meet its fellow when it is moved inwards, though, if it is carried in front of the other, adduction is con- siderable. In both states the head moves in the opposite direction to the shaft. Thus, as the femur is abducted, the head descends, and the greater part of the articular surface projects below the acetabulum ; and when tlie limb is raised to its utmost the great trochanter comes to rest on the margin of the acetabulum, so as to limit farther motion. As the limb descends and approaches the other, the head rises into the socket of the joint, and is securely lodged, finally, in the deepest part of the cavity. In abduction, the inner band of the capsule is tightened over the pro- jecting head of the femur, the upper part being relaxed. And in adduc- tion, tlie outer band of the capsule is rendered tense enough to arrest the movement. Hip Joint Opened, to show the interarticular or round ligament. a. Part of the capsule. 6. Ligamentum teres: c, its pubic, and, d, its ischial attachment. 604 DISSECTION OF THE THIGH. Dislocation may take place in both these lateral movements, the edge of the cotyloid cavity serving as the fulcrum by which the femur can be lifted out of the hollow ; in the one case (adduction) the neck of the femur rests on the brim of the acetabulum, and in the other (abduction) the great trochanter is supported on the margin of the joint-socket. After a dislocation has been reduced, the state of adduction, with the knees fastened together, is the securest position in which the limb can be placed, inasmuch as the head of the femur then occupies the deepest part of the acetabulum. In circumduction, the four kinds of angular motion above noticed take place in succession, viz., flexion, abduction, extension, and adduction ; and the limb describes a cone, whose base is at its extremity, and apex at the union of the neck with the shaft of the femur. This movement is less free than in the shoulder-joint, because of the greater bend between the neck and shaft of the femur. There are two kinds of rotation, internal and external : in the former, the great toe is turned in ; and in the latter, the more extensive of the two, it is moved outwards. In rotation inwards, the head of the femur rolls backwards horizontally across the acetabulum, the great trochanter being put forwards ; and the shaft of the bone revolves around a line inside it, which passes from the head to the inner condyle. During this movement the posterior half of the capsule is put on the stretch, and the anterior is relaxed. In rotation out the head of the bone rolls forwards across the cotyloid cavity, and the great trochanter is brought backwards, whilst the shaft of the femur moves round the line on its inner side before noticed. The fore part of the capsule is now put on the stretch, and the hinder is rendered loose. The movement of rotation is destroyed by fracture of the neck of the bone. Its degree is proportioned to the length of the neck, and is there- fore greater in the femur than in the humerus. Use of bend of femur. By means of the angle at the union of the neck with the shaft, the pelvis is more firmly prop[)ed than it would be if the neck was in a line with the rest of the femur. It permits also greater surface contact between the head of the femur and the hip bone, since the whole head can be lodged in the cotyloid cavity in progression ; and gives greater security to the joint in flexion and extension, for if the neck and shaft of the bone were in a line, only half of the articular surface could enter the socket of the innominate bone in walking, and running. The important movement of rotation is also duo to this angle ; and greater space is obtained through it for the location of the a,'U8 pollicis. D. Marks the four lumbricales muscles, but the letters are put on the tendons of the flexor digitorum perforans. E. Tendon of flexor perforatus. F. Tendon of flexor perforans. a. Sheath of flexor tendons. H. Tendon of poroneus longus. Arteries : a. Internal plantar. t). External plantar. c. Branch to abductor minimi digiti. d. Branch to outer side of little toe. Nerves : i. Internal, and 2, external plantar. 4. Branch to flexor brevis pollicis. It supplies offsets to the muscles between which it lies, and others to the outer side of the foot for anastomosis with the peroneal artery. PLANTAR NERVES. 619 The PLANTAR NERVES (fig. 210) are derived from the bifurcation of the posterior tibial trunk behind the inner ankle. They are two in num- ber, like the arteries, and have the same anatomy as those vessels, for each accompanies a plantar artery; but the larger nerve lies with the smaller bloodvessel. The internal plantar nerve (') courses between the short flexor of the toes and the abductor pollicis, and giving but few muscular offsets, divides into four digital branches (^ ^, *, *) for the supply of both sides of the inner three toes, and half the fourth ; it resembles thus the median nerve of the hand in the distribution of its branches. Muscular otfsets are given by it to the short flexor of the toes (perfo- ratus) and the abductor pollicis; and a few superficial twigs perforate the fascia. The four digital nerves have a numerical designation, and the first is nearest th? inner border of the foot. The branch Q) to the inner side of the great toe is undivided, but the others are bifurcated at the cleft be- tween the toes. Muscular branches are furnished by these nerves before they reach the toes; thus, the first (most internal) supplies the flexor brevis pollicis; the second gives a brancli to the inner lumbrical muscle, and the third, to the next lumbricalis. Digital nerves on the toes. Each of the outer three nerves, being divided at the spot mentioned, supplies the contiguous sides of two toes, whilst the first belongs alone to the inner side of the great toe ; all give offsets to the teguments, and the cutis beneath the nail, and articular fila- ments are distributed to the joints as in the fingers. The external plantar nerve (*) is spent chiefly in the deep muscles of the sole of the foot, but it furnishes digital nerves to both sides of the little toe, and the outer side of the next. It corresponds in its distribution with the ulnar nerve in the hand. It has the same course as the external plantar artery, and divides at the outer margin of the flexor brevis digitorum into a superficial and a deep portion : — the former gives origin to two digital nerves ; but the latter accompanies the arch of the plantar artery into the foot, and will be dis- sected afterwards. AVhilst the external plantar nerve is concealed by the short flexor of the toes, it gives muscular branches to the abductor minimi digiti and the flexor accessorius. The digital branches of the external plantar nerve (^ ^) are two. One C^) is undivided ; it is distributed to the outer side of the little toe, and gives offsets to the flexor brevis minimi digiti, and oftentimes to the inter- osseous muscles of the fourth space. The other (^) bifurcates at the cleft between the outer two toes, and supplies their collateral surfaces : this nerve communicates in the foot with the last digital branch of the internal plantar nerve. On the sides of the toes the digital nerves have the same distribution as those from the other plantar trunk, and end like them in a tuft of fine branches at the extremity of the digit. Dissection (fig. 211). To complete the preparation of the second layer of muscles, the origin of the abductor pollicis should be detached from the OS calcis, and the muscle should be turned inwards. The internal plantar nerve and artery, and the superficial portion of the external plantar nerve, are to be cut across and thrown forwards ; but the external plantar artery 620 DISSECTION OF THE FOOT. and tlie nerve with it are not to be injured. All the fat, and the loose tissue and fascia, are then to be taken away near the toes. Second layer of muscles (fig. 211). In this layer are the tendons of the two flexor muscles at the back of the leg, viz., flexor longus digi- torum and flexor longus poUicis, which cross one another. Connected with the former, soon after it enters the foot, is an accessory muscle ; and at its division into pieces four fleshy slips (lumbricales) are added to it. The tendon of the flexor longus digitorum (fig. 211,®), whilst entering the foot beneath the annular ligament, lies on tiie internal lateral ligament of the ankle joint. In the foot it is directed obliquely towards the centre, where it is joined by the tendon of the flexor longus pollicis and the accessory muscle, and divides into tendons for the four outer toes. Each tendon enters the sheath of the toe with, and beneath a tendon from the flexor brevis, e. About the centre of the metatjirsal phalanx the tendon of the long flexor, f, is transmitted through the other, and passes onwards to be inserted into the base of the ungual phalanx. Uniting the flexor tendons with the two nearest phalanges of the toes are liga- mentous bands (lig. brevia), one to each, as in the hand; and the one fixing the flexor perforans is anterior (p. 277). Action. It flexes the last phalangeal joint, and combines with the short flexor in bending the metacarpo-phalangeal joint. If it acted by itself it would tend to bring the toes somewhat inwards, in consequence of its ob- lique position in the foot. The lumhricales (fig. 211, ^) are four small muscles between the tendons of the flexor longus digitorum. Each arises from two tendons, with the exception of the most internal, and this is connected with the inner side of the tendon to the second toe. Each is inserted by a slip into the tibial side of the base of the metatarsal phalanx in the four outer toes, and sends an expansion to the aponeurotic covering on the dorsum of the phalanx. Thfe muscles decrease in size from the inner to the outer side of the foot. Actio7i. These small muscles will assist the flexors in bending the metatarso-phalangeal joint of the four outer toes ; and through their union with the long extensor tendon they will aid that muscle in straightening the two phlangeal joints. The accessorius muscle (fig. 211 ^) has two heads' of origin: — One is mostly tendinous, and is attached to the under or the outer surface of the OS calcis, and to the ligamentum longum phmtoe ; the other is large and fleshy, and springs from the inner or concave surface of the calcaneum. The fibres end in aponeurotic bands, which join the tendon of the flexor longus digitorum about the centre of the foot, and contribute slips to the pieces of that tendon going to the second, tliird, and fourth digits (Turner). The muscle is bifurcated behind, and the heads of origin are separated by the long plantar ligament. On it lie the external plantar vessels and nerve ; and the flexor brevis digitorum conceals it. Action. By means of its offsets to the tendons of certain digits the muscle helps to bend those toes. And from its position on the outer side and behind the long flexor to which it is united, it will oppose the inward action of that muscle, and will assist the other flexors in bending the toes directly back. The tendon of the flexor longus pollicis (fig. 211, ^) is deeper in the sole of the foot than the flexor longus digitorum ; and, directed to the root of the great toe, it enters the digital slieath, to be inserted into the base of the ungual phalanx. It is united to the long flexor tendon by a THIRD LAYER OF MUSCLES. 621 strong tendinous process which, joined by bands of the accessorius, is con- tinued into the pieces of that tendon belonging to the second and third toes (Turner). Between the calcEineum and the internal malleolus this tendon lies in a groove in the astragalus ; and in the foot it occupies a hollow below the inner projection (sustentaculum tali) of the os calcis, being enveloped by a synovial membrane. Action. For the action of this mnscle on the great toe, see page 610. Through the slip that it gives to the tendons of the flexor longus going to the second and third toes, it may bend those digits with the great toe. Dissection (fig. 212). For the dissection of the third layer of muscles, the accessorius and the tendons of the long flexor are to be cut through near the calcaneum, and turned towards the toes. Whilst raising the tendons the external plantar nerve and artery are not to be interfered with ; and two small nerves and vessels to the outer two lumbricales are to be looked for. Afterwards the areolar tissue is to be taken from the muscles now brought into view. Third layer of muscles (fig. 212). Only the short muscle of the great and little toes enter into this layer. On the metatarsal bone of the great toe the flexor brevis pollicis lies, and external to it is the adductor pollicis ; on the metatarsal bone of the little toe is placed the flexor brevis minimi digiti. Crossing the heads of the metatarsal bones is the trans- versals pedis muscle. The fleshy mass between the adductor pollicis and the short flexor of the little toe consists of the interossei muscles of the next layer. The FLEXOR BREVIS POLLICIS musclc (fig. 212, ^) is tendinous and pointed posteriorly, but bifurcated in front. It is attached behind to the inner part of the under surface of the cuboid bene, and to a prolongation from the tendon of the tibialis posticus. Near the front of the metatarsal bone of the great toe it divides into two heads, which are inserted into the sides of the base of the metatarsal phalanx. Resting on the muscle at one part, and in the interval between the heads at another, is the tendon of the flexor longus pollicis. The inner head joins the abductor, and the outer is united with the adductor pollicis. A sesamoid bone is developed in the tendon connected with each head. Action. By its attachment to the first phalanx it flexes the metatarso- phalangeal joint of the great toe. The ADDUCTOR roLLicis (fig. 212, ^), which is larger than the pre- ceding muscle and external to it, arises from the sheath of the tendon of the peroneus longus, and from the bases of the second, third, and fourth metatarsal bones. Anteriorly the muscle is united with the outer head of the short flexor, and is inserted with it into the base of the metatarsal phalanx of the great toe. To the inner side is the flexor brevis ; and beneath the outer the exter- nal plantar vessels and nerve are directed inwards. Action. Its first action will be to adduct the great toe to the others, and it will help afterwards in bending the matatarso-phalangeal joint of the toe. The TRANSVERSALis PEDIS (fig. 212, °) is placed transversely over the heads of the metatarsal bones. Its origin is by fleshy bundles from the capsule of the metatarso-phalangeal articulations of the four outer toes (frequently not from the little toe), and from the fascia covering the inter- ossei muscles. Its insertion into the great toe is united with that of the adductor pollicis. 622 DISSECTION OF THE FOOT. Fig. 212. Fig 213. Third View of thk Sole op the Foot. (Illustrations of Dissections.) Muscles : A. Flexor brevis pollicis. B. Adductor pollicis. c. Flexor brevis minimi digiti. D. Transversalis pedis. Arteries : a. Internal plantar, cnt. h. External plantar ; and c. Its four digital branches. Nerves : 1. Internal plantar. 2. External plantar. 3. Its superficial part, cut. 4. The deep part, with the plantar arch. 5. Two offsets to the outer two lumbricales muscles. FouKTH View of the Soi-k of the Foot. (Illustrations of Disseciious.) Muscles : 0. Three plantar interossei. 1. Four dorsal interossei. Arteries : a. Internal plantar, cut. b. External plantar. c. Its four digital branches. d. Plantar arch. €. Anteiior tibial entering the sole. /. Arteria magna pollicis Q . Branch to inner side of great toe. h. Branch for the supply of great toe and the next. Nerves : 1. Internal plantar, cut. 2. External plitntar. 3. Its superficial; and 4. its deep part, both cut ; the latter supply- ing offsets to the interossei muscles. The cutaneous surface is covered by the tendons, and the nerves of the toes ; and the opposite surface is in contact witli the interossei muscles and the digital vessels. Action. It will adduct the great toe to the others, and then approxi- mate the remaining toes. PLANTAR ARCH OF VESSELS. 623 The FLEXOR BREVis MINIMI DiGiTi (fig. 212, °) is a Small narrow- muscle on the metatarsal bone of the little toe, and resembles one of the interossei. Arising behind from the metatarsal bone and the sheath of the peroneiis longus, it blends with the inferior ligament of the metatarso- phalangeal articulation, and is inserted into the base of the metatarsal phalanx of the toe; it is united also by fleshy fibres with the fore part of the metatarsal bone. Action. Firstly it bends the metatarso-phalangeal joint, and nextly it draws down and adducts the fore part of the fifth metatarsal bone. Dissection (fig. 2* 3). In order that the deep vessels and nerves may be seen, the flexor brevis and adductor pollicis are to be cut through at the posterior part, and tlirown towards the toes ; but the nerves supplying them are to be preserved. Beneath the adductor lie the plantar arch, and the external plantar nerve, with their branches; and in the first interos- seous space is the part of the dorsal artery of the foot that enters the sole. All these vessels and nerves with their branches require careful cleaning. The muscles projecting between the metatarsal bones are the interossei ; the fascia covering them should be removed. The PLANTAR ARCH (fig. 213, d) is the part of the external plantar artery which reaches from the base of the metatarsal bone of the little toe to the back of the first interosseous space : internally the arch is completed by a communicating branch from the dorsal artery of the foot (e) (p. 624). It is placed across the tarsal ends of the metatarsal bones, in contact w^ith the interossei, but under the flexor tendons, and the adductor pollicis to which it gives many branches. Venae comites lie on the sides of the artery, and the external plantar nerve accompanies it. From the front or convexity of the arch the digital branches are sup- plied, and from the opposite side small nutritive branches arise. Three small arteries, the posterior perforating^ leiwe the under part: these pass to the dorsum of the foot through the three outer metatarsal spaces, and anastomose with the dorsal interosseous branches of the ante- rior tibial artery. The digital branches (c) are four in number, and supply both sides of the three outer toes, and half the next. One to the outer side of the little toe is single; but the others lie over the interossei in the outer three metatarsal spaces, but beneath the transversalis pedis (fig. 212), and bi- furcate in front to supply the contiguous sides of two toes. They give fine oflsets (fig. 212) to the interossei, to some lumbricales, and the transver- salis pedis; and at the point of division they send small communicating branches — anterior perforating, to join the interosseous arteries on the dorsum of the foot. The first digital runs on the outer side of the little toe, supplying the flexor brevis minimi digiti, and distributes small arteries to the teguments of the outer border of tlie foot. The second belongs to the sides of the fifth and fourth toes, and fur- nishes a branch to the outer lumbrical muscle. The third is distributed to the contiguous sides of the fourth and third toes, and emits a branch to the third lumbricalis. The fourth, or most internal, corresponds with the second interosseous space, and ends like the others on the third and second digits ; it may assist in supplying the third lumbricalis. 624 DISSECTION OF THE FOOT. The last two digital are joined by superficial digitalis branches of the internal plantar at the root of the toes. On tlie sides of tlie toes the disposition of the arteries is like that of the digital in the hand. They extend to the end, where tliey unite in an arch, and give offsets to the sides and ball of the toe : and the artery on the second digit anastomoses with a branch from the anterior tibial artery. Near the front of both the metatarsal and the next phalanx, they form anastomotic loops beneath the flexor tendons, from which the phalangeal articulations are supplied. The DORSAL ARTERY OF THE FOOT (fig. 213, e) enters the sole at the posterior part of the first (inner) metatarsal space, and ends by inoscu- lating with the plantar arch. By a large digital artery it furnishes branches to both sides of the great toe and half the next, in the same man- ner as the radial artery in the hand is distributed to one digit and a half. The digital branch (^f) (art. magna pollicis) extends to the front of the first interosseous space, and divides into collateral branches (//) for the contiguous sides of the great toe and the next; near the head of the meta- tarsal bone it sends inwards, beneath the flexor muscles, a digital branch {g) for the inner side of the great toe. These arteries have the same arrangement along the toes as the other digital branches; and that to the second digit anastomoses at the end of the toe with a branch of the plantar arch. External plantar nerve (fig. 213, ^). The deep branch (*) of this nerve accompanies the arch of the artery, and ends internally in the ad- ductor pollicis. It furnishes branches to all the interossei ; to the trans- versalis pedis; and to the two external lumbrical muscles. The nerve corresponds with the deep portion of the ulnar nerve in the hand. Dissection. It will be needful to remove the transversalis pedis muscle, to see a ligament across the heads of the metatarsal bones. The transverse metatarsal ligament is a strong fibrous band, like that in the hand (p. 280), which connects together all the metatarsal bones at their anterior extremity. A thin fascia covering the interossei muscles is connected to its hinder edge. It is concealed by the transversalis pedis, and by the tendons, vessels, and nerves of the toes. Dissection. To complete the dissection of the last layer of muscles, the flexor brevis minimi digiti may be detached and thrown forwards. Di- viding then the metatarsal ligament between the bones, the knife is to be carried directly backwards for a short distance in the centre of each inter- osseous space, exce{)t the first, in order that the two interossei muscles may be separated from each other. All the interossei are visible in the sole of the foot. The fascia covering the muscles should be taken away if any remains, and the branches of the external plantar nerve to tiiem should be dissected out. Fourth layer of muscles (fig. 213). In the fourth and last layer of the foot are contained the interossei, and the tendons of the tibialis pos- ticus and peroneus longus. The interossei muscles (fig. 213) are situate in the intervals between the metatiirsal bones : they consist of two sets, plantar and dorsal, like the interossei in the hand. Seven in number, there are three plantar and four dorsal ; and two are found in each space, except the innermost. The plantar interossei^ o, belong to three outer metatarsal bones (fig. 213), and are slender fleshy slips. They arise from the under and inner FOURTH LAYER OP MUSCLES. 625 surfaces of those bones ; and are inserted partly into the tibial side of the base of the metatarsal phalanx of the same toes, and partly by an expan- sion from each to the extensor tendons on the dorsum of the phalanx. These muscles are smaller than the dorsal, and are placed more in the sole of the foot. The dorsal interossei, i, one in each space, arise by two heads from the lateral surfaces of the bones between which they lie ; and are inserted like the others into the side, and on the dorsum of the metatarsal phalanx of certain toes : Thus, the inner two muscles belong to the second toe, one to each side ; the next appertains to the outer side of the third toe ; and the remaining one to the outer side of the fourth toe. The interossei are crossed by the external plantar artery and nerve, and their digital branches, and lie beneath the transversalis pedis and the meta- tarsal ligament. The posterior perforating arteries pierce the hinder ex- tremities of the dorsal set. Action. Like the interossei of the hand (p. 281) they will contribute to the bending of the metatarso-phalangeal joints by the flexors, and will help the extensors to straighten the last two phalangeal joints. They can act also as abductors and adductors of the toes. Thus the plantar set will bring the three outer towards the second toe ; and the dorsal muscles will abduct from the middle line of the second toe — the two attached to that digit moving it to the right and left of the said line. Dissection. Following the tendon of the tibialis posticus muscle from its position behind the inner malleolus to its insertion into the scaphoid bone, trace the numerous processes that it sends forwards and outwards. Open also the fibrous sheath of the tendon of the peroneus longus, which crosses from the outer to the inner side of the foot. The tendon of the tibialis posticus is continued forwards over the internal lateral ligament of the ankle joint, and over the astragalo scaphoid articulation to be inserted into the prominence of the scaphoid bone. From its insertion processes are continued to many of the other bones of the foot : One is directed backwards to the margin of the groove in the os calcis for the tendon of the flexor longus pollicis. Two offsets are directed forwards ; one to the internal cuneiform bone ; the other, much the largest, is attached to the middle and outer cuneiform, to the os cuboides, and to the bases of the second, third, and fourth metatarsal bones. In other words, pieces are fixed into all the tarsal bones except one (astragalus) ; and into all the metatarsal bones except two (first and fifth). Where the tendon is placed beneath the articulation of the astragalus, it contains a sesamoid bone, or fibro-cartilage. The tendon of the peroneus longus muscle winds round the cuboid bone, and is continued inwards in the groove on the under surface, to be inserted into the internal cuneiform bone, and the base of the metatarsal bone of the great toe ; and sometimes by a slip into the base of the second metatarsal bone. In the sole of the foot (fig. 213), it is contained in a sheath which is crossed, towards the outer part, by the fibres of the long plantar ligament prolonged to the tarsal ends of the third and fourth metatarsal bones ; but it is formed internally only by areolar tissue. A separate synovial mem- brane lubricates the sheath. Where the tendon turns round the cuboid bone it is thickened, and con- tains fibro-cartilage or a sesamoid bone. 40 626 DISSECTION OF THE LEG. Section VI. THE FRONT OF THE LEG. Position. The limb is to be raised to a convenient height by blocks beneath the knee, and the foot is to be extended in order that the muscles on the front of the leg may be put on the stretch. Dissection. To enable the dissector to raise the skin from the leg and foot, one incision should be made along the middle line from the knee to the toes, and this should be intersected by cross cuts at the ankle and the root of the toes. After the flaps of skin are reflected, the cutaneous vessels and nerves are to be looked for. At the upper and inner part of the leg are some fila- ments from the great saphenous nerve ; and at the outer side others, still smaller, from the external popliteal nerve. Perforating the fascia in the lower third, on the anterior aspect, is the musculo-cutaneous nerve, whose branches should be pursued to the toes. On the dorsum of the foot is a venous arch, which ends laterally in the saphenous veins. On the outer side is the external saphenous nerve ; and about the middle of the instep the internal saphenous nerve ceases. In the interval between the great toe and the next is the cutaneous part of the anterior tibial nerve. The digital nerves should be traced to the ends of the toes by removing the integuments : and after the several vessels and nerves are dissected, the fat is to be taken away, in order that the fascia may be seen. The venous arch on the dorsum of the foot has its convexity turned forwards, and receives digital branches from the toes ; at its concavity it is joined by small veins from the instep. Internally and externally it unites with the saphenous veins. The internal saphenous vein begins at tlie inner side of the great toe, and in the arch. It ascends along the inner side of the foot, and in front of the inner ankle to the inside of the leg (p. 606). Branches enter it from the inner side and sole of the foot. The external saphenous vein begins on the outside of the little toe and foot, as well as in the venous arch ; and it is continued below the outer ankle to the back of the leg (p. 606). Cutaneous Nerves (fig. 214). Tiie superficial nerves on the front of the leg and foot are derived mainly from branches of the popliteal trunks, viz., from the musculo-cutaneous and anterior tibial nerves of the external popliteal, and from the external saphenous nerve of the internal popliteal. Some inconsiderable offsets ramify on the sides of the leg from the internal saphenous and external popliteal. The musculo-cutaneous nerve (J) ends on the dorsum of the foot and toes. Perforating the fascia in the lower third of the leg with a cutane- ous artery, it divides into two principal branches (inner and outer), which give dorsal digital nerves to the sides of all the toes, except the outer part of the little toe and the contiguous sides of the great toe and the next. The branches may be traced in the integument as far as the end of the last phalanx. The inner branch (^) communicates with the internal saphenous nerve, CUTANEOUS NERVES ON THE FRONT. 6-27 \ A h and supplies the inner side of the foot and great Fig. 214. toe : it joins also the anterior tibial nerve. The outer branch (*) divides into three nerves ; these lie over the three outer interosseous spaces, and bifurcate at the web of the foot for the con- tiguous sides of the four toes corresponding with those spaces ; it joins the external saphenous nerve on the outer part of the foot. The anterior tibial 7ierve Q) becomes cutane- ous in the first interosseous space, and is distri- buted to that space, and to the opposed sides of the o-reat toe and the next. The musculo-cuta- o ... neous nerve joins it, and sometimes assists in supplying the same toes. The external saphenous nerve (fig. 207, ^) comes from the back of the leg below the outer ankle, and is continued along the foot to the out- side of the little toe ; all the outer margin of the foot receives nerves from it, and the offsets to- wards tlie sole are larger than those to the dor- sum. Occasionally it supplies both sides of the little toe and part of the next. Internal saphenous nerve (^). A part of this nerve is continued along tlie vein of the same name to the middle of the instep, where it ceases mostly in the integuments, but some branches pass through the deep fascia to end in the tarsus. T\\e fascia of the front of the leg is thickest near the knee joint, where it gives origin to muscles. It is fixed laterally into the tibia and fibula. Intermuscular septa are prolonged from the deep surface ; and one of these, which is at- tached to the fibula, separates the muscles on the front from those on the outer side of the leg. Superiorly the fascia is connected to the heads of the leg bones, but inferiorly it is continued to the dorsum of the foot. Above and below the ankle joint it is strength- ened by some transverse fibres, and gives origin to the two parts of the anterior annular ligament ; and below the end of the fibula it forms another band, the external annular ligament. Dissection. The fascia is to be removed from the front of the leg and the dorsum of the foot, but the thickened band of the annular ligament above and below the end of the tibia is to be left. In separating the fascia from the subjacent muscles, let the edge of the scalpel be directed upwards. In like manner the fascia may be taken from the peronei muscles on the outside of the fibula, but without destroying the band (external annular ligament) below that bone. On the dorsum of the foot the dorsal vessels with their nerve are to be displayed, and the tendons of the short and long extensors of the toes are THK AND Cutaneous Nerves of Front of the Leo Foot. 1. Anterior tibial. 2. Muscalo-cutaneous, with 3, its inner, and 4, its outer piece ; the usual distri- bution is not shown in the cut. .5. Internal saphenous. 6. Offsets of external popliteal. 628 DISSECTION OF THE LEG. to be traced to the ends of the digits. In the leg the anterior tibial nerve and vessels are to be followed from the dorsum into their intermuscular space, and are then to be cleaned as high as the knee. The anterior annular ligament consists of two parts, upper and lower, which confine the muscles in their position : the former serving to bind the fleshy parts to the bones of the leg, and the latter to keep down the tendons on the dorsum of the foot : — The upper part (fig. 215, ^), above the level of the ankle-joint, is at- tached laterally to the bones of the leg ; it possesses one sheath with synovial membrane for the tibialis anticus. The lower part is situate in front of the tarsal bones. It is inserted externally by a narrow piece into the upper surface of the os calcis, in front of the interosseous ligament ; and internally, where it is thin and widened, into the plantar fascia and the inner malleous. In this piece of the ligament there are three sheaths : an inner one for the tibialis anticus ; an outer for the extensor longus digitorum and peroneus tertius ; and an intermediate one for the extensor pollicis. Separate synovial membranes line the sheaths. The external annular ligament is placed below the fibula, and is at- tached on the one side to the outer malleolus, and on the other to the os calcis. Its lower edge is connected by fibrous tissue to the sheaths of the peronei muscles on the outer side of the os calcis. It contains the two lateral peronei muscles in one compartment ; and this is lined by a syno- vial membrane, which sends two otiTsets below into the sheaths of the peronei muscles. The MUSCLES ON THE FRONT OF THE LEG (fig. 215) are three in num- ber. The large muscle next the tibia is the tibialis anticus ; that next the fibula, the extensor longus digitorum ; whilst a small muscle, appa- rently the lower part of the last, with a separate tendon to the fifth meta- tarsal bone, is the peroneus tertius. The muscle between the tibialis and extensor digitorum, in the lower half of the leg, is the extensor pollicis. On the dorsum of the foot only one muscle appears, the extensor brevis digitorum. The TIBIALIS ANTICUS (fig. 215, ') reaches the tarsus : it is thick and fleshy in the upper, but tendinous in the lower part of the leg. It arises from the outer tuberosity and the upper half or more of the tibia ; from the contiguous part of the interosseous ligament ; and from the fascia of the leg and the intermuscular septum between it and the next muscle. Its tendon begins below the middle of the leg, and passes through com- partments in the pieces of the annular ligament, to be inserted into the internal cuneiform bone, and the metatarsal bone of the great toe. The muscle is subaponeurotic. It lies at first outside the tibia, resting on the interosseous membrane, but it is then placed, successively, over the end of the tibia, the ankle-joint, and the inner tarsal bones. The outer border touches the extensor muscles of the toes, and conceals the anterior tibial vessels. Action. Supposing the foot not fixed, the tibialis bends the ankle, moves the great toe towards the middle line of the body, and raises the inner border of the foot. If the foot is fixed it can lift the inner border with the tibialis posticus, and support the foot on the outer edge. If tiie tibia is slanting backwards, as when the advanced limb reaches the ground in walking, it can bring forwards and make steady that bone. FLEXORS OF THE ANKLE-JOINT. 629 The EXTENSOR PROPRiDS POLLicis (fig. 215) IS deeply placed at its origin between the former muscle and the extensor long'us digltorum, but its tendon becoms superficial on the dorsum of the foot. The muscle arises from the middle three-fifths of the narrow anterior part on the inner surface of the fibula, and from the interosseous ligament for the same dis- tance. At the ankle it ends in a tendon, which comes to the surface through a sheath in the lower piece of the annular ligament, and continues over the inner part of the tarsus to be inserted into the base of the last phalanx of the great toe. The anterior tibial vessels lie on the inner side of the muscle as low as the sheath in the ligament, but afterwards on the outer side of its tendon, so that they are crossed by it beneath the ligament. Action. It straightens the great toe by extending the phalangeal joints, and afterwards bends the ankle. When the foot is fixed on the ground and the tibia slants backwards, the muscle can draw forwards that bone. The EXTENSOR LONGUS DiGiTORUM (fig. 215, ^) is flcshy in the leg, and tendinous on the foot, like the tibial muscle. Its origin is from the head and three-fourths of the narrow part of the inner surface of the fibula; from tlie external tuberosity of tlie tibia, and about an inch (above) of the interosseous membrane ; and from tlie fascia of the leg and the intermus- cular septum on each side. The tendon enters its sheath in the annular ligament with the peroneus tertius, and divides into four pieces. Below the ligament these slips are continued to the four outer toes, and are in- serted into the middle and ungual phalanges : — On the metatarsal phalanx the tendons of the long and short extensor join with prolongations from the interossei and lumbricales to form an aponeurosis ; but a tendon from tlie short extensor is not united to the expansion on the little toe. At the further end of this phalanx the apo- neurosis is divided into three parts — a central and two lateral ; the central piece is inserted into the base of the middle phalanx, while the lateral unite at the front of the middle, and are fixed into the ungual phalanx. In the leg the muscle is placed between the peronei on the one side, and the tibialis anticus and extensor proprius poUicis on the other. It lies on the fibula, the lower end of the tibia, and the ankle-joint. On tlie foot the tendons rest on the extensor brevis digitorum ; and the vessels and nerve are internal to them. Action. The muscle extends the joints of the four outer toes from root to tip, as in the fingers ; and still acting, bends the ankle-joint. If the tibia is inclined back, as when the foot reaches the ground in walking, it will be moved forwards by this and the other muscles on the front of the leg. The peroneus tertius is situate below the extensor longus digitorum, from which it is seldom separate. It arises from the lower fourth of the narrow part of the inner surface of the fibula, from the lower end of the interosseous ligament, Jind from the intermuscular septum between it and the peroneous brevis muscle. And it is inserted into the tarsal end (up- per surface) of the metatarsal bone of the little toe. This muscle has the same connections in the leg as the lower part of the long extensor, and is contained in the same space in the annular ligament. Action. The muscle assists the tibialis in bending the ankle, and in 630 DISSECTION OF THE LEG drawing forwards the fibula when the leg is advanced to make a step in walking. The ANTERIOR TIBIAL ARTERY (fig. 215, *) extends from the bifurca- tion of the popliteal trunk to the front of the ankle joint. At this spot it becomes the dorsal artery of the foot. Fig. 215. .^9'.- ,tt;''-!'':f.'ffA Anterior Tibial Vess-.l and Muscles (Quain's Arteries). 1. Tibialus antlcns muscle. 3. Part of anterior annular ligament. 2. Extensor poUicis and extensor longus digi- 4. Anterior tibial artery: the nerve outside it torum drawn aside. is the anterior tibial. The course of the artery is forwards through the aperture in the upper part of the interosseous membrane, along the front of that membrane, and over the tibia to the foot. A line from the inner side of the head of the fibula to the centre of the ankle will mark the position of the vessel. For a short distance (about two inches) the artery lies bstween the ANTERIOR TIBIAL VESSELS. 631 tibialis anticus and the extensor longus digitorum ; afterwards it is placed between the tibial muscle and the extensor proprius pollicis till near the lower end, where the last muscle becomes superficial, and crosses to the inner side. The vessel rests on the interosseous membrane in two-thirds of its extent, being overlapped by the fleshy bellies of the contiguous muscles, so that it is at some depth from the surface ; but it is placed in front of the tibia and the ankle joint in the lower third, and is compara- tively superficial between the tendons of the muscles. VenfB comites entwine around the artery, covering it very closely with cross branches on the upper part. The anterior tibial nerve approaches the tibial vessels about the middle third of the leg, and continues with them, crossing once or twice : at the lower end of the artery the nerve lies on the outer side. Branches. In the leg the anterior tibial artery furnishes mostly mus- cular offsets, but near the knee and ankle the following named branches take origin. a. Cutaneous branches arise at intervals ; and the largest accompanies the musculo-cutaneous nerve, and supplies the contiguous muscles. h. A recurrent branch arises as soon as the trunk appears above the interosseous membrane, and ascends in the tibialis anticus to the knee joint : on the joint it anastomoses w ith the other articular arteries. c. Malleolar arteries (internal and external) spring near the ankle joint, and are distributed over the ends of the tibia and fibula. The internal is the least regular in size and origin ; the external anastomoses with the anterior peroneal artery. d. Some small articular branches are supplied from the lower end of the artery to the ankle joint. The DORSAL ARTERY of the foot is the continuation of the anterior tibial, and extends from the front of the ankle joint to the posterior part of the first interosseous space : at this interval it passes downwards between the heads of the interosseous muscle, to end in the sole (p. 624). The artery is supported by the inner row of the tarsus, viz., the astra- galus, and the scaphoid and cuneiform bones ; and it is covered by the integuments and the deep fascia, and by the inner piece of the extensor brevis muscle. The tendon of the extensor pollicis lies on the inner side, and that of the extensor longus digitorum on the outer side, but neither is near the vessel. The veins have the same position with respect to the artery as in the leg ; and the nerve is external to it. Peculiarities. On the dorsum of the foot the artery is often removed further outwards than the line from the centre of the ankle to the posterior part of the first interosseous space. Further, the place of the arter}-- may be taken by a large anterior peroneal branch . Branches. Offsets are given to the bones and ligaments of the foot : those from the outer side of the vessel are named tarsal and metatarsal from their distribution. A small interosseous brancli is furnished to the first metatarsal space. a. The tarsal branch arises opposite the scaphoid bone, and runs be- neath the extensor brevis digitorum to the outer side of the foot, where it divides into twigs that inosculate with the metatarsal, plantar, and ante- rior peroneal arteries : it supplies offsets to the extensor muscle beneath which it lies. 632 DISSECTION OF THE LEG. b. The metatarsal branch takes an arched course to the outer part of the foot, near the base of the metatarsal bones and beneath the extensor muscle, and anastomoses with the external plantar and tarsal arteries. c. From the arch of the metatarsal branch three dorsal interosseous arteries are furnished to the three outer metatarsal spaces ; and the exter- nal of these sends a branch to the outer side of tlie little toe. They sup- ply the interossei muscles and divide at the cleft of the toes into two small dorsal digital branches. At the fore part of the metatarsal space each interosseous branch joins a digital artery in the sole of the foot by means of the anterior per- forating twig ; and from the beginning of each a small branch, posterior perforating, descends to the plantar arch. d. The first interosseous branch (art. dorsalis pollicis) arises from the trunk of the artery as this is about to leave the dorsum of the foot ; it ex- tends forwards in the space between the first two toes, and is distributed by dorsal digital pieces like the other dorsal interosseous offsets. The ANTERIOR TIBIAL VEINS havc the same extent and connections as the vessel they accompany. They take their usual position along the artery, one on each side, and form loops around it by cross branches ; they end in the popliteal vein. The branches they receive correspond with those of the artery ; and they communicate with the internal saphenous vein. Dissection. To examine the extensor brevis digitorum on the dorsum of the foot, cut through the tendons of the extensor longus and peroneus ter- tius below the annular ligament, and throw them towards the toes. The hinder attachment of the muscle to the os calcis is to be defined. The EXTENSOR BREVIS DIGITORUM arises from the outer surface of the OS calcis in front of the sheath for the peroneus brevis muscle, and from the lower band of the anterior annular ligament. At the back of the meta- tarsal bones the muscle ends in four tendons, which spring from as many fleshy bellies, and are inserted into the four inner toes. The tendon of the great toe has a distinct attachment to the base of tlie metatarsal phalanx ; but the rest are united to the outer side of the long extensor tendons, and assist to form the expansion on the metatarsal phalanx (p. G29). The muscle lies on the tarsus, and is partly concealed by the tendons of the long extensor. Its inner belly crosses the dorsal artery of the foot. Action. Assisting the long extensor, it straightens the four inner toes, separating slightly from each other. Dissection. The branches of artery and nerve which are beneath the extensor brevis will be laid bare by dividing that muscle near its front, and turning it upwards. By cutting through the lower band of the annular ligament over the tendon of the extensor pollicis, and throwing outwards the external half of it, — the different sheaths of the liganient, the attachment to the os calcis, and the origin of the extensor brevis digitorum from it may be ob- served. The anterior tibial and musculo-cutaneous nerves are now to be followed upwards to their origin from the external popliteal : and a small branch to the knee-joint from the same source is to be traced through the tibialis anticus. Nerves to the front of the leg. Between the fibula and the pero- neus longus muscle the external popliteal nerve divides into recurrent articular, musculo-cutaneous, and anterior tibial branches. PERONEI MUSCLES. 633 The recurrent articular branch is small, and takes the course of the artery of the same name through the tibialis anticus muscle to the knee joint. The musculo-cutaneous nerve is continued between the extensor longus digitorum and the peronei muscles to the lower third of the leg, where it pierces the fascia, and is distributed to the dorsum of the foot and the toes (p. G26). Before the nerve becomes cutaneous it furnishes branches to the two larger peronei muscles. The anterior t'lhial nerve (fig. 215) (interosseous) is directed beneath the extensor longus digitorum, and reaches the tibial artery about the middle third of the leg. From this spot it takes the course of the vessel along the foot to the first interosseous space (p. 627). In the leg it crosses the anterior tibial vessels once or more, but on the foot it is generally external to the dorsal artery. Branches. In the leg the nerve supplies the anterior tibial muscle, the extensors of the toes, and the peroneus tertius. On the dorsum of the foot it furnishes a considerable branch to the short extensor ; this is enlarged, and gives offsets to the articulations of the foot. Muscles on the outer part of the leg (fig. 209). Two muscles occupy this situation, and are named peronei from their attachment to the fibula ; they are distinguished by the terms longus and brevis. Intermus- cular processes of fascia, which are attached to the fibula, isolate these muscles from others. The PERONEUS LONGUS (fig. 209, ®), the more superficial of the two muscles, passes into the sole of the foot round the outer border. It arises from the head, and the anterior surface of the shaft of the fibula for two- thirds of the length, gradually tapering downwards ; from the external border nearly to the malleolus ; and from the fascia and the intermuscular septa. Inferiorly it ends in a tendon which is continued through the ex- ternal annular ligament, with the peroneus brevis, lying in the groove at the back of the external malleolus ; and it passes finally in a separate sheath, below the peroneus brevis along the side of the calcis and through the groove in the outer border of the cuboid bone, to the sole of the foot. Its position in the foot, and its insertion are described before (p. 625). In the leg the muscle is immediately beneath the fascia, and lies on the peroneus brevis. Beneath the annular ligament it is placed over the middle piece of the external lateral ligament of the ankle with the peroneus brevis, and is surrounded by a single synovial membrane common to both. The extensor longus digitorum and the soleus are fixed to the fibula late- rally with respect to it, one being on each side. Action. With the foot free the muscle extends the ankle : then it can depress the inner, and raise the outer border of the foot in the movement of eversion. When the foot rests on the ground it assists to lift the os calcis, and the w^eight of the body as in standing on the toes, or in walking. And in rising from a stooping posture it draws back the fibula. The PERONEUS BREVIS (fig. 209, ^) reaches the outer side of the foot, and is smaller than the preceding muscle, and inferior in position to it. It arises from the anterior surface of the shaft of the fibula for about the lower two-thirds, extending upwards by a pointed piece internal to tlie other peroneus ; and from the intermuscular septum in front. Its tendon passes with that of the peroneus longus through the external annular liga- ment, and is placed next the fibula as it turns below this bone. Escaped 634 DISSECTION OF THE LEG. from the ligament, the tendon enters a distinct fibrous sheath, which con- ducts it along the tarsus to its insertion into the projection at the base of the metatarsal bone of the little toe. In the leg the muscle reaches in front of the peroneus longus. On the outer side of the os calcis it is contained in a sheath above the tendon of the former muscle ; and each sheath is lined by a prolongation from the common synovial membrane behind the outer ankle. Action. If the foot is unsupported this peroneus extends the ankle, and moves the foot upwards and outwards in eversion. Like the long muscle, it is able if the foot is supported to raise the heel, and to bring back the fibula as the body rises from stooping. Section VII. LIGAMENTS OF THE KNEE, ANKLE, AND FOOT. Directions. In examining the remaining articulations of the limb, the student may take first the knee-joint, unless this has become dry ; in that case the ligaments of the leg, ankle-joint, and foot may be dissected whilst the knee is being moistened. Dissection. For the preparation of the ligaments of each articulation, it is sufiicient to detach the muscles and tendons from around it, and to remove the areolar tissue or fibrous structure which may obscure or con- ceal the ligamentous bands. In the knee a kind of aponeurotic capsule is to be defined on the front of the joint. Some tendons, namely, those of the biceps, popliteus, adductor magnus, and semimembranosus, are to be followed to their insertion, and a part of each is to be left. Articulations of the knee. The knee is the largest hinge joint in the body, and is formed by the contiguous ends of the tibia and femur, with the patella. The articular surfaces of the bones are covered with cartilage, and are maintained in apposition by strong and numerous liga- ments. The capsule (fig. 216) is an aponeurotic covering on the front of the joint, which closes the wide intervals between the anterior and tlie lateral ligaments ; and is derived from the fascia lata united with fibrous offsets of the extensor and flexor muscles. It covers the anterior and tlie exter- nal lateral ligament, being inserted below into the heads of the tibia and fibula ; and it blends on the inner side with the internal lateral ligament. It is not closely applied to the synovial membrane, but it is united below with the interarticular fibro-cartilages. Dissection. Four external ligaments, anterior and posterior, internal and external, are situate at opposite points of the articulation. The poste- rior and the internal lateral ligament will appear on the removal of the areolar tissue from their surfaces ; but the anterior and the external lateral are covered by the aponeurosis on the fore part of the joint, and will not be laid bare till this has been cut through. If there is a second external lateral band present, it is not concealed by the aponeurosis. Tlie external lateral ligament (fig. 216, ^) is round and cord-like. It is attached to the outer condyle of the femur below the tendon of the gas- LIGAMENTS OF KNEE, 635 m ^Bocnemius, and descends vertically between two pieces of the tendon of ^the biceps to a depression on the upper and outer part of the head of the fibula. Beneath the ligament are the tendon of the popliteus, and the external lower articular vessels and nerve. Fig. 216. Fiff. 217. ExTKRNAL Ligament of the Knee-joint. (Bourgery). 1. Anterior ligament. 2. External lateral ligament. .3. Interosseous ligament. 4. Part of the capsule. Internal Ligament of the Knee-joint. (Bourgery.) 1. Tendon of the extensor muscle endiug below in the ligament of the patella, 2. 3. Internal lateral ligament. 4. Lateral part of the capsule. A second fasciculus is sometimes present behind the other, but it is not attached to the femur : it is connected above with the gastrocnemius, and below with the posterior prominence of tlie head of the fibula. The tendon of the biceps is inserted by two pieces into the points on the head of the fibula ; and from the anterior of these there is a prolonga- tion to the head of the tibia. The external lateral ligament passes be- tween the pieces into which the tendon is split. Tiie tendon of the popliteus may be followed by dividing the posterior ligament. It arises from the fore part of the oblong depression on the outer surface of the external condyle of the femur. In its course to the outside of the joint, it crosses tiie external semilunar fibro-cartilage and tlie upper tibio-peroneal articulation. When the joint is bent, the tendon lies in the hollow on the condyle ; but slips out of that groove when the limb is extended. The tendon of the adductor magnus is inserted into a tubercle on the internal condyle of the femur, above the attachment of the internal lateral ligament. Tlie internal lateral ligament (fig. 217, ^) is attached to the condyle of the femur, where it blends with the capsule ; but becoming thicker below, and separate from the rest of the capsule, it is fixed for about an inch into the inner surface of the tibia, below the level of the ligamentum patella?. The tendons of the sartorius, gracilis, and semitendinosus muscles lie over the ligament ; and the tendon of the semimembranosus, and the internal lower articular vessels and nerve are beneath it. To the posterior ed^e some fibres of the tendon of the semimembranosus are added. 636 DISSECTION OF THE LEG. The tendon of the semimemhranosus muscle is inserted beneath tlie internal lateral ligament into an impression at the back of the inner tuber- osity of the head of the tibia : between it and the bone is a synovial bursa. The tendon sends some fibres to the internal lateral ligament, a prolongation to join the fascia on the popliteus muscle, and another to the posterior ligament of the knee joint. The posterior ligament (ligament of Winslow), wide and membranous, covers the back of the joint between the two lateral, and is joined by fibres from the tendon of the semimembranosus, which are directed across the joint to the outer side. It is fixed below to the head of the tibia behind the articular surface, and above to the femur, but by strongest fibres opposite the intercondyloid notch. Numerous apertures exist in it for the passage of the vessels and nerves to the interior of the articulation ; and the tendon of the popliteus pierces it. The anterior ligament (ligamentum patellar) (fig. 217, ^), part of the tendon of insertion of the extensor muscle of the knee (p. 571), is two inches long. Superiorly it is attached to the lower part of the patella, and to the depression on the inner surface of the apex ; and inferiorly it is inserted into the tubercle of the head of the tibia, and into an inch of the bone below it. An expansion of the triceps extensor covers it ; and a bursa intervenes between it and the top of the tubercle of the tibia. Dissection (fig. 218). To see the reflections of the synovial membrane raise the knee on blocks, and open the joint by an incision on each side, Fiff. 218. The Capsule of the Knee-joint cut across, and the Patella thrown down to show the NAMED Folds of the Synovial Sac. a. Mucous liganieat. h. Internal, and c, external alar ligament. above the patella. When the anterior part of the capsule with the patella is thrown down, a fold (mucous ligament) will be seen extending from the intercondyloid fossa of the femur to a mass of fat below the patella. On each side of the knee-{)an is a similar fold (alar ligament) over some fat. The limb may be laid flat on tiie table, and some of the posterior liga- SYNOVIAL SAC AND FAT AROUND KNEE. 637 raent may be removed, to show the pouches of the synovial membrane which project behind over the condyles of the femur ; but the limb is to be replaced in the former position before the parts are learnt. The synovial membrane (fig. 218) lines the interior of the capsule, and is continued to the articular ends of the bones. It invests the interarticular cartilages after the manner of serous membranes, and sends a pouch be- tween the tendon of the po|)liteus and the external fibro-cartilage and the head of the tibia ; it is also reflected over the strong crucial ligaments at the back of the joint. There are three named folds of the synovial membrane. One in the centre of the joint is the mucous ligament (a), which contains small ves- sels and some fat, and extends from the interval between the condyles to the fat below the patella. Below and on each side of the patella is another fold — alar ligament (5 and c), which is continuous with the former below the patella, and is placed over a mass of fat : the inner (6) is prolonged farther than the outer by a semilunar piece of the serous membrane. At the back and front of the articulation pouches are prolonged beneath the tendons of muscles. Behind there are two, one on each side, between the condyle of the femur and the tendinous head of the gastrocnemius, ►n the front, the sac projects under the extensor muscle one inch above 'the articular surface ; and if it communicates with the bursa in that situa- tion, it will reach two inches above the joint surface of the femur. When the joint is bent there is a greater length of the serous sac above the patella. Fat around the joint. Two large masses are placed above and below the patella, and some fat is located around the crucial ligaments. The infra- patellar mass, the largest of all, fills the interval between the patella with its ligament and the head of the tibia, and gives origin to the ridges of the synovial membrane. From it a piece is continued around the patella : but it is larger at the inner margin of the bone, than on the outer, and overhangs the inner perpendicular facet. During extension of the joint the infra-patellar pad is applied to, and lubricates tiie articular surfaces of the femur. The supra-patellar pad is interposed between the triceps extensor and the femur around the top of the synovial sac, and is greater on the outer than on the inner side. Dissection (fig. 219). The ligamentous structures within the capsule will be brought into view, whilst the limb is still in the same position, by throwing down the patella and its ligament, and clearing away the fat behind it. In this step the student must be careful of a small transverse band which connects anteriorly the interarticular cartilages. The remains of the ca[)sule and other ligaments, and the synovial mem- brane are next to be cleared away from the front and back of the crucial ligaments, and from the interarticular cartilages. Whilst cleaning the posterior crucial the limb is to be placed flat on the table with the patella down ; and the student is to be careful of a band before it from the exter- nal fibro-cartilage, or of two bands, one before and the other behind it. Ligaments within the capsule. The ligamentous structures within the capsule consist of the central crucial ligaments, and of two plates of fibro- cartilage on the head of the tibia. The crucial ligaments (fig. 219) are two strong fibrous cords between the ends of the tibia and femur, which maintain in contact the bones. They cross one another somewliat like the legs of the letter X, and have 638 DISSECTION OF THE LEG Fig. 219. received their name from that circumstance. One is much anterior to the other at the attachment to the tibia. The anterior ligament (/) is most oblique in its direction, and is smaller than the posterior. Inferiorly it is attached in front of the spine of the tibia, close to the inner articular surface, reaching back to the inner point of the spine: superiorly it is inserted by its posterior shorter tibres into the back of the outer condyle of the femur, and by the anterior or longer into the hinder part of the intercondyloid fossa. The posterior ligament (e) is almost vertical between the bones at the back of the joint. By the lower end it is fixed to the hindermost impres- sion of the hollow behind the spine of the tibia, near the margin of the bone; and above its posterior shorter fibres are in- serted into the inner condyle along the side of the oblique curve, whilst the anterior and longer reach the fore part of the inter- condyloid fossa. The use of these ligaments in the move- ments of the joint, after the external liga- ments have been cut through may now be studied. As lonor as both lineaments are whole the bones cannot be separated from each other. Rotation in of the tibia is stopped by the anterior crucial. Rotation out is not checked by either ligament ; for the bands uncross in the execution of the movement, and will permit the tibia to be put hind foremost. Supposing the tibia to move, as in straightening the limb, the anterior pre- vents that bone being carried too far for- wards by the extensor tendon, or by force ; and the lignment is brought into action at the end of extension, because the tibia is being put in front of the femur. Its use is shown by cutting it across, and leaving the posterior entire, as then the tibial articulat- ing surfaces can be placed in front of the femoral in the half bent state of the joint. The posterior crucial arrests the too great movements backwards of the tibia by the flexors or by force ; and it is stretched in extreme flexion, in which the tibia is being drawn back from the femur. This use will be exemplified by cutting across the posterior (in another joint or in another dissection) and leaving entire the anterior : when this has been done the articular surfaces of the tibia can be carried nearly altogether behind the condyles of the femur. The interarticular or semilunar Jibro-cartilages (fig. 220) cover partly on each side the articular surface of the tibia. They are thick at the outer margin, where they are united by fibres to the capsule, and are thin at the inner edge ; they are hollowed on the upper surface, so as to assist in giving depth to the fossjE for the reception [ntekakticclar Ligaments of the Kneb-Joint. a. Internal, and 6. External semilunar flbro-cartilage ; the latter rather displaced by the bending of the joint. e. Posterior crucial ligament, with rf, the ascending ligamentous band of the external flbro-cartilage. /. Anterior crucial ligament. g. Patellar surface of the fennur. INTRA-OAPSULAR LIGAMENTS OF KNEE. 639 of the condyles of the femur, but are flattened below. Inserted into the tibia at their extremities, they are coarsely fibrous at their attachment to the bone, like the crucial ligaments ; and they become cartilaginous only where they lie between the articular surfaces. The synovial membrane is reflected over thom. The internal cartilage {a) is ovoid in form, and is a segment of a larger circle than the external. In front it is attached by a pointed part to the anterior margin of the head of the tibia, in front of the anterior crucial liga- ment. At the back, where it is much Fig. 220. View op the Head of the Tibia with the flsro cartilages attached : the crucial ligaments have been cut THROUGH. a. Inner, and b, outer semilunar fibro-car- tilage. c. Transverse, and d, ascending or poste- rior band (cat) of the external carti- lage. e. Posterior, and /, anterior crucial liga- ment. wider, it is fixed to the inner lip of the hollow behind the spine of the tibia, between the attachment of the other cartilage and the posterior crucial liga- • ment. The external cartilage (5) is nearly circular in form, and is connected to the bone within the points of attach- ment of its fellow. Its anterior part is fixed in front of the spine of the tibia, close to the outer articular surface, and opposite the anterior crucial ligament, which it touches ; and its posterior extremity is inserted behind and be- tween the two osseous points of the spine. This fibro-cartilage is less closely united to the capsule than the internal, for the fore part is in the cen- tre of the joint, and the tendon of the popliteus muscle separates it behind from that membrane. The outer fibro-cartilage is provided with two accessory bands, one at the fore part, the other behind. The anterior or transverse ligament (c) is a narrow band of fibres be- tween the semilunar cartilages at the front of the joint. Sometimes it is scarcely perceptible. The posterior or ascending hand (d), thicker and stronger than the other, springs from the back of the outer fibro-cartilage, and is inserted into the femur as a single band (fig. 219, d) in front of the posterior crucial, or as two bands — one being before, and the other behind that ligament. Use. The fibro-cartilages deepen the sockets of the tibia for the recep- tion of the condyles of the femur, and fill the interval between the articu- lar surfaces of the bones at the circumference of the joint ; they moderate the injurious efi^ect of pressure of the one bone on the other; and cause the force of shocks to be diminished in transmission. In flexion and extension they move forwards and backwards with the tibia. During flexion they recede somewhat from the fore part of the joint, and surround the condyles of the femur; but in extension they are flattened out on the surface of the tibia. Of the two cartilages the ex- ternal moves the most in consequence of its ends being less attached to the capsule. 640 DISSECTION OF THE LEG. In rotation the fibro-cartilages follow the tibial movements, but the ex- ternal is most displaced by the projecting outer condyle of the femur. The accessory bands in front and behind serve to retain in place the least fixed external fibro-cartilage ; thus the anterior ligament keeps for- wards the fore part of that cartilage in flexion, and the posterior secures the back of the same from displacement in rotation. Articular surfaces of the hones. The end of the femur is marked by a patellar and two tibial surfaces. The patellar is placed in the middle line above the others ; it is hol- lowed along the centre, with a slanting surface on each side, the outer being the larger of the two. The surfaces for contact w^ith the tibia, two in number, occupy the ends of the condyles, and are separated from the patellar impression by an oblique groove on each side. On the centre of each is a somewhat flat- tened part, which is in contact with the tibia in standing ; and at the posterior third is a more convex portion, which touches the tibia in rota- tion. The inner condyle of the femur is curved at its anterior third, the con- cavity being directed out: this has been named the "oblique curvature." Close to the curved part is a semilunar facet, which touches the perpen- dicular surface of the patella in extreme flexion. On the head of the tibia are two slight articular hollows, the inner being the deeper and larger, which rise towards the middle of the bone, on the points of the tibial spine. Tlie joint-surface of the patella is marked by the following impressions. Close to the inner edge is a narrow perpendicular facet, and along the lower border is a similar transverse mark. Occupying the rest of the bone is a squarish surface, which is subdivided by a vertical and a trans- verse line into two pairs of marks — upper and lower. (Goodsir, Edinb. Med. Jour., 1855.) Movements of the joint. The chief movements of the knee are two in number, bending and straightening, like the elbow ; but there is, in addi- tion, rotation of the tibia when the joint is bent. Flexion and extension. Each of these movements may be divided into stages for the purpose of particularizing changes in its direction. Inflexion the tibia with its fibro-cartilages moves backwards round the end of the femur ; and its extent is limited by the extensor muscle, and by the meeting of the calf of the leg with the thigh. For the anterior third of the movement the tibia is directed down and in along the oblique curve of the inner condyle, giving rise to rotation inwards of that bone ; but for the posterior two-thirds, the tibia passes straight back over the condyles. All the external ligaments are relaxed, except the anterior ; and both crucials are put on the stretch towards the end of flexion. In extension the tibia is carried forwards until it comes into a straight line with the femur, when the uniting ligaments prevent its farther progress. In the hinder two-thirds of the movement the tibia has a straight course over the condyles of the femur ; but in the anterior third the leg- bone is directed up and out over the oblique curve of the inner condyle, and is rotated out. All the external ligaments except the anterior are tightened, and the crucial cords help to limit extrejne extension. MOVEMENTS OF KNEE AND PATELLA. 641 Rotation. A half bent state of the knee is necessary for this movement, for the purpose of relaxing the anterior crucial and the external ligaments ; and the foot must be free. Then, the tibia with its fibro-cartilages rotates around a vertical axis, the great toe being turned in and out. During rotation in the inner articular surface of the tibia touches the condyle of tiie femur and moves backwards; and the outer articular sur- face, separated by a slight interval from the thigh bone, passes forwards. Botli lateral ligaments are loose ; but the anterior crucial is gradually tightened, and stops finally the motion. In rotation out the opposite movement of the tibia takes place — the in- ner articular surface being directed forwards, and the outer backwards. The internal lateral ligament controls the movement by its fibres being made tense. The crucials have not any influence on the motion (p. 637). Movement of the 'patella. When the knee passes from flexion to exten- sion the patella crosses it obliquely from the outer to the inner side, touch- ing in succession different parts of the femoral articular surfaces. In complete flexion the knee-pan lies on the outer side of the joint below the femur, where it is scarcely perceptible, and is fixed in its situa- tion. It touches the semilunar surface on the inner condyle by its per- pendicular facet, and the under part of the outer condyle by the upper and outer mark on its square surface. When the joint is passing from flexion to extension, the upper pair of impressions on the square surface of the patella, and the lower pair rest^ successively on the pulley-surface of the femur. In complete extension, the patella is situate at the upper and inner part of the knee-joint, wiiere it is very prominent, with its apex and the ligament of the patella directed down and out to the tibia. For the most part the knee-pan articular surface is raised above the trochlea of the femur, w^hich it touches only at the upper edge by its lower trans- verse facet. Peroneo-tibial articulations. The tibia and fibula are united by ligamentous bands at the extremities, where they touch ; and by an inter- osseous ligament between the shafts of the bones. Dissection. The muscles are to be taken away from the front and back of the interosseous ligament ; and the loose tissue is to be removed from a small band in front of, and behind the upper and lower ends of the tibia and fibula. The UPPER ARTICULATION has very small movement, and the structures between the ends of the bones are two small bands, anterior and posterior. The anterior ligament extends over the joint from the outer tuberosity of the tibia to the head of the fibula. The posterior ligament, thinner than the anterior, is attached to the bones behind the joint : it is covered by the tendon of the popliteus muscle and a prolongation of the synovial membrane of the knee-joint. The articular surfaces are covered with cartilage : and a synovial mem- brane lining the articulation projects backwards so as to touch that of the knee-joint. The LOWER ARTICULATION posscsscs an anterior and a posterior band, together with an inferior ligament between the ends of the bones. The anterior ligament reaches obliquely from the lower end of the tibia to the fibula ; and the posterior has attachments behind the articulation similar to those of the band in front. The inferior ligament closes the space between the contiguous ends of 41 642 DISSECTION OF THE LEG the tibia and fibula, and consists of transverse yellowish fibres distinct from the posterior ligament. It is fixed on one side to the end of the fibula above the pit : and on the other it is inserted into the contiguous part of the tibia, and into the posterior edge of the articular surface so as to assist in deepening the hollow into which the astragalus is received. The interosseous ligament fills the interval between the bones of the leg, and serves as an aponeurotic partition between the muscles on the front and back of the leg. Its fibres are directed downwards for the most part from the tibia to the inner surface of the fibula : but some few cross in the opposite direction. Internally it is fixed to the outer edge of the tibia : and externally, to the oblique line on the inner surface of the fibula along the upper three- fourths, but to the posterior border along the lower fourth of that bone. Both superiorly and inferiorly is an aperture which transmits vessels. The upper opening, about an inch in length, lies along tlie neck of the fibula, and gives passage to the anterior tibial vessels. Tlie lower aper- ture is close to the fibula, about an inch above the lower end, and is only large enough for the small anterior peroneal vessels. Some strong irregular bundles of fibres, the inferior interosseous liga- ment, extend between the bones below the aperture for the anterior pero- neal artery. It may be seen after the examination of the ankle joint by sawing longitudinally the lower ends of the leg bones. Movement. Very little movement is allowed in the tibio-peroneal articu- lations, as the chief use of the fibula is to give security to the ankle joint and attachment to muscles of the leg. In the upper joint there is a slight gliding from before back. In the lower articulation the ligaments permit some yielding of the fibula to the pressure of the astragalus, as when the weight of the body is thrown on the inner side of the foot ; but if the force is violent the lower fourth of that bone will be fractured sooner Fig. 221. Internal Lateral Ligament op the Anklb (altered from Bourgery). 1. Posterior piece. 2. Middle piece. .3. Anterior piece of the inner ligament. 4. Inferior calcaneo-Mcaphoid ligament. than the ligaments. Articulation of the ankle (fig. 221). Like the knee, the ankle is a ginglymoid or hinge joint. In this joint the upper surface of the astragalus is received into an arch formed by the lower ends of the tibia and fibula ; and the four liga- ments belonging to this kind of articulation connect together the bones. Dissectio7i. To make the dissec- tion required for the ligaments of the ankle joint, the muscles, and the fibrous tissue and vessels must be removed from the front and back of the articulation. For the purpose of defining the lateral ligaments, the limb must be placed first on one side and then on the other. The internal ligament is wide and strong, and lies beneath the tendon of the tibialis posticus. LIGAMENTS OF ANKLE-JOINT. 643 The external is divided into three separate pieces ; and to find these the peronei muscles, and the remains of the annular ligament below the outer malleolus, should be taken away. The anterior or tibio-tarsal ligament is a thin fibrous membrane, which is attached to the tibia close to the articular surface ; and to the upper part of the astragalus near the articulation with the scapiioid bone. In the ligament are some rounded intervals and apertures for vessels. On the sides it joins the lateral ligaments. The posterior ligament is thinner internally than externally ; and it is inserted into the tibia and the astragalus, close to the articular surfaces of the bones. Towards the outer part it consists of transverse fibres, which are fixed into the hollow on the inner surface of the external malleolus. The internal lateral or deltoid ligament (fig. 221) is attached by its upper or pointed part to the inner malleolus, and by its base to the astraga- lus, the OS calcis, and the scaphoid bone, by fibres which radiate to their insertion in this manner : — The posterior (^) are directed to the hinder part of the inner surface of the astragalus ; the middle (^) pass vertically to the sustentaculum tali of the os calcis ; and the anterior (''), which are thin and oblique, join the inferior calcaneo-scaphoid ligament and the inner side of the scaphoid bone. The tendons of the tibialis posticus and flexor longus digitorum are in contact with this ligament. The external lateral ligament (fig. 222) consists of three separate pieces, anterior, middle, and posterior, which are attached to the astragalus and the OS calcis. The anterior piece Q) is a short flat band, which is directed from the fore part of the malleolus to the side of the astragalus in front of the lateral articular surface. The middle portion (^) is flattened and de- scends from the tip of the malleolus to the outer surface of the os calcis, about the middle. The posterior C^) is the strongest, and is almost hori- zontal in direction ; it is connected externally to the pit on the inner sur- face of the malleolus, and is inserted into the posterior part of the astraga- lus behind the upper articular surface, extending to the groove for the flexor pollicis tendon. The posterior and middle fasciculi are placed beneath the peronei mus- cles. The middle part is but slightly in contact above with the synovial membrane of the ankle joint ; and both it and the posterior piece touch the synovial membrane between the astragalus and the os calcis. Dissection. Dividing the ligaments of the ankle joint, separate the as- tragalus from the bones of the leg, to see the osseous surfaces entering into the joint. The synovial membrane of the joint lines the capsule, and is simple in its arrangement. Articular surfaces. On the tibia there are two articular faces, one of which corresponds with the end of the shaft, and the other with the mal- leolus. On the fibula the surface of the malleohis which is turned to the astragalus is tipped with cartilage. The astragalus has a central articular surface, wider before than behind and trochlear-shaped, which touches the end of the tibia : and on its sides are articular impressions for contact with the malleoli, but the outer one is the largest. Movement. Only the movements of flexion and extension are permitted in the ankle : in the former state the toes are raised towards the fore part of the leg ; and in tlie latter, they are pointed towards the ground. liijlexion the astragalus moves backwards so as to project behind; and 644 DISSECTION OF THE LEG Fig. 222. all further motion is arrested by the meeting of the anterior edge of the tibia with that bone. The posterior ligament is stretched over the projecting head of the astragalus, and the posterior and middle parts of tlie external lateral, and the posterior piece of the internal lateral ligament, are made tense. In extension the astragalus moves forwards over the end of the tibia, and projects anteriorly. A limit to the movement is imposed by the meet- ing behind of the astragalus with the tibia. The lateral ligaments are partly made tight as in flexion, for instance the anterior piece of the external, and the fore and middle portions of the internal When the joint is half extended so that the small hinder part of the as- tragalus is brought into the arch of the leg bones, a slight movement of the foot inwards and outwards may be obtained ; but if the foot is forcibly extended the portions of the lateral ligaments, attached to the astragalus, prevent this lateral movement by their tightnCvSS. Dissection. The joints of the foot will be demonstrated by removing from both the dorsum and the sole all the soft parts which have been examined. Between the difterent tarsal bones bands of ligament extend, which will be defined by removing the areolar tissue from the intervals between them (fig. 223). It will be more advantageous for the student to clean all the ligaments before he proceeds to learn any, than to prepare only the bands of one articulation at a time. Articulation of the astragalus and os calcis. These bones are kept together by two joints, and a strong interosseous ligament ; and there are also thin bands at the outer side and behind. The posterior ligament (fig. 223, a) consists of a few fibres between the bones, where they are grooved by the tendon of the flexor pollicis ; and the external ligament {b) is connected to the sides of the astragalus and OS calcis, near the middle piece of the external lateral ligament of the ankle joint. The interosseous ligament (fig. 223, c) consists of strong vertical and oblique fibres, which are attached above and below to tlie depressions on the contiguous surfaces of the two bones. This band extends across the bones, and its depth is greatest at the outer side. In a subsequent stage of the dissection (p. 647) articular surfaces will be seen between the bones, viz., one behind the interosseous ligament, and one in front of it, with two synovial membranes. Movement. Under the influence of the weight of the body, as in stand- ing, the astragalus moves down and in (not straight forwards) with External Lateral Ligament of the Ankle (altered from Bourgery). 1. Anterior part. 2. Posterior part. 3. Middle part of the outer ligament. 4. Interoaseusof astragalus and os calcis. 5. External calcaneo-scaphoid ligament. LIGAMENTS OF TARSAL BONES. 645 flattening of the arch of the foot, so that its head projects against the calcaneo-scaphoid ligament. In this state the interosseous ligament is put on the stretch. Fig. 223. a. Posterior, &, external, and c, in- terosseous ligaments between astragalus and os calcis. d, Astragalo-scaphoid. e. External calcaneo-scaphoid. /. Internal, and g, upper calcaneo- cuboid ligaments. h. Dorsal scapho-cuboid band. t, k, I. Dorsal external, middle, and internal scapho-cuneiform longitudinal bands. n. Dorsal transverse bands between the cuneiform and cuboid bones. View of the Dorsal Ligaments op the Tarsus. When the pressure of the leg is removed the astragalus is carried up and out by the tightened ligaments and muscles, and the arch of the foot is restored. Astragalus with the scaphoid bone. The head of the astragalus is received into the hollow of the scaphoid bone, and is united to it by a dorsal ligament ; but the place of plantar and external lateral ligaments is supplied by strong bands between the os calcis and the scaphoid bone, which will be noticed below. The dorsal astragalo-scaphoid ligament (fig. 223, d) is attached to the astragalus close to the articulation, and to the dorsal surface of the sca- phoid bone : its attachments will be better seen when it is cut through. Dissection. The external ligament of the articulation may be seen on the dorsum of the foot in the hollow between the os calcis and the scaphoid bone. Supposing the tendon of the tibialis posticus removed, the inferior ligament will be detined in the sole of the foot by cutting some fibro-car- tilaginous substance from it. The inferior ligament (fig. 225, c) (calcaneo-scaphoid) is attached behind to the fore part of the sustentaculum tali of the os calcis, and in front, to the hollow on the sustentaculum tali of the os calcis, and in front, to the hollow on the under surface of the scaphoid bone. In the upright posture of the body the tendon of the tibialis posticus is beneath it in the sole of the foot ; and on it the head of the astragalus rests. The external calcaneo-scafhoid (fig. 223, e) is placed outside the head of the astragalus, and serves as a lateral ligament to the astragalo-sca- phoid articulation ; it is about three-quarters of an inch deep. Behind, it is fixed to the upper part of the os calcis, between the articular surfaces for the cuboid bone and astragalus ; and in front it is inserted into the outer side of the os scaphoides. A synovial membrane serves for this articulation, and sends back a pro- longation to the joint between the fore part of the os Cidcis and the astra- galus. Articular surfaces. The head of the astragalus has two articular faces ; a smaller, below, for the os calcis ; and a larger one, elongated transversely 646 DISSECTION OF THE LEG, and larger externally than internally, for the scaphoid bone. The sca- phoid bone is hollowed, and is widest externally. Movement. The scaphoid moves down and in over the transversely elongated head of the astragalus, or up and out in the opposite direction. As the bone is forced downwards, the upper and external ligaments of the joint are made tight ; and when the scaphoid is moved in the opposite way the strong inferior ligament is put on the stretch. The OS calcis with the cuboid bone. The ligaments in this arti- culation are plantar and dorsal, the former being much the strongest ; and there is also an internal band. The dorsal ligament (fig. 223, g) (superior calcaneo-cuboid) is a rather thin fasciculus of fibres, wiiich is attached near to the contiguous end of the OS calcis and the cuboid bone ; it is sometimes divided into two parts, or it may be situate at the outer border of the foot. At tlie inner side of the os cuboides is a stronger internal hand (fig. 223, f) from the os calcis, this is fixed behind to the upper part of the os calcis external to the band to the scaphoid bone, and in front to the contiguous inner side of the os cuboides. Fig. 224. Fiff. 225. Plantar Ligaments of the Foot (Bourgery). 1. Long plantar ligament. 2. Deep portion of the inferior calcaneo-cu- boid ligament. 3. Tendon of the peroneus longus muscle. View of the Inferior Ligaments of the Tarsal Bones. a. Long plantar, cut. h. Short or deep inferior calcaneo-cuboid liga- ment. c. Inferior calcaneo-scaphoid. d. Plantar transverse scapho-cuboid ligament. e. Dorsal inner scapho-cuneiforra extending into the sole of the foot. /. Plantar transverse ligament between the inner and middle cuneiform bones. g. Plantar transverse band between the cuboid and outer cuneiform. The inferior calcaneo-cuhoid ligament in the sole of tlie foot (fig. 224) is much the strongest, and is divided into a superficial and a deep part : — TRANSVERSE TARSAL ARTICULATION. 647 The superficial portion, ligamentum longum plantce Q) is attached to |he under surface of the os calcis from near the posterior to the anterior ^tubercle : its fibres pass forwards to be connected with- the ridge on the under surface of the cuboid bone ; but the most internal are continued over the tendon of the peroneus longus muscle, assisting to form its sheath, and are inserted into the bases of the third and fourth metatarsal bones. The deep piece of the ligament (fig. 225, 5), seen on division of the superficial, extends from the tubercle and the hollow on the fore part of the under surface of the os calcis, to the cuboid bone internal or posterior to the ridge. A simple synovial membrane belongs to the articulation. Articular surfaces. Both bones are flattened towards the outer part of the articulation ; but at the inner side the os calcis is hollowed from above down, and the os cuboides is convex to fit into it. Movement. In this joint the cuboid bone possesses two movements, viz., an oblique one, down and in, and up and out. In the downward movement the internal lateral and the upper ligament are made tight ; and in the upward, the calcaneo-cuboid ligaments of the sole are stretched. Transverse tarsal articulation (fig. 223). The joints of the astragalus with the scaphoid, and os calcis with the cuboid bone, form a transverse articulation across the foot in which the movements of inversion and eversion take place. In inversion the great toe is adducted ; the inner border of the foot is shortened, and is raised from the ground so that the sole looks inwards. The scaphoid bone passes down and in over the head of the astragalus, being approximated near to the inner malleolus ; and the cuboid bone moves down and in on the os calcis. The cuneiform bones are raised at the same time and contribute to the movement (p. 648). The ligaments connected with both joints on the dorsum of the foot are tightened. In eversion the inner border of the foot descends and lengthens, the outer border is raised, and the great toe is abducted from the middle line of the body. The same two tarsal bones are directed up and out, and the cuneiforms sink. The ligaments in the sole of the foot of both joints now come into use to prevent over movement. Dissection. Saw through the astragalus in front of the attachment of the interosseous ligament between it and the os calcis; and remove the head of the bone for the purpose of observing the lower and outer calcaneo- scaphoid ligaments. Tlien the interosseous ligament uniting the astragalus and the os calcis is to be cut through, to demonstrate its attachments, the articular surfaces of the bones, and the synovial sacs (p. 644). Articular surfaces of the two hinder tarsal bones. There are two articular surfaces, anterior and posterior, to both the astragalus and the os calcis. Tlie liinder one of the os calcis is convex transversely and the anterior is concave ; but sometimes the last is subdivided into two. The surface of the astragalus will liave a form exactly the reverse of that of the os calcis, viz., the hinder one concave and the anterior convex ; the anterior is seated on the head of the astrasralus. 648 DISSECTION OF THE LEG. Dissection. The calcaneo-cuboid joint may be opened to see the articu- lar surfaces: and the student is to keep in mind tluit all the other articula- tions of the foot are to be opened for the like purpose, even should directions not be given. Articulations of the scaphoid bone. The scaphoid bone articu- lates in front with the three cuneiform bones, and laterally with the os cuboides. In the articulation with the cuneiform hones (fig. 223) there are three longitudinal dorsal ligaments (i, k, /), one to each bone ; but tlie inner- most is the strongest and widest, and extends round the inside of the articulation into the sole of the foot (fig. 225, e). The place of plantar bands is supplied by processes of the tendon of the tibialis posticus. A synovial membrane (common of the tarsus) lines the articulation, and sends forwards prolongation between the cuneiform bones. In the articulation with the os cuhoides there is a dorsal oblique band of fibres (fig. 223, h) between the contiguous surfaces of the bones ; a plantar transverse band (fig. 225, c?), which is concealed by the tendon of the tibialis posticus ; and a strong interosseous ligament. Where the bones touch, the surfaces are tipped with cartilage, and are furnished with a prolongation from the common synovial membrane of the tarsus. Articulatoins of the cuneiform bones. These bones are united to one another by cross bands ; and the external one articulates with the OS cuboides after a similar manner. The three cuneiform bones are connected together by short transverse dorsal bands (fig. 223, 7i) between the upper surfaces. Similar plantar ligaments are wanting, except one between the two innermost (fig. 225,/). There are also interosseous ligaments between the contiguous surfaces of the bones. Laterally there are articular surfaces between the bones, with offsets of the common synovial membrane. Where the external cuneiform touches the cuboid bone the surfaces are covered with cartilage. A dorsal ligament (fig. 223, n) passes transversely between the two ; and a plantar ligament (fig. 225, g) takes a similar direction. Between the bones there is also an interosseous ligament. This joint is furnished either with a distinct synovial sac, or with a prolongation of the common tarsal synovial membrane. The synovial membrane of the articulations of the cuneiform bones is common to many of the bones of tlie tarsus. Placed between the scaphoid and the three cuneiforms it sends one prolongation forwards between the inner and middle cuneiform to the joints with the second and third meta- tarsal bones ; another, outwards, to the articulation of the scaphoid with the cuboid bone ; and sometimes a third to the joint between the external cuneiform and the os cuboides. Articular snrfaces. On the scaphoid are three articular faces, the inner being rounded, and the other two fiattened. The three cuneiforms unite in a shallow elliptical hollow, which is most excavated internally. Movement. The cuneiform bones glide up and out on the scaphoid in inversion of the foot, and down and in in eversion ; and the inner one moves more than the others in consequence of the shape of the articular surfaces, and the attachment to it of the tibialis anticus. When the bones pass down the dorsal ligaments are made tight : and LIGAMENTS OF TARSUS WITH METATARSUS. 649 Fig. 226. as they rise the interosseous and transverse plantar bands will keep them united. In standing and in progression these bones are separated somewhat from each other with diminution of the arch of the foot, and stretching of the transverse ligaments which connect them. Articulation of the mktatarsal bones. The bases of the four outer metatarsal bones are connected together by dorsal, plantar, and in- terosseous ligaments ; and where their lateral parts touch, they are covered with cartilage, and have offsets of a synovial sac. The dorsal ligaments (fig. 22G) are small trans- verse bands from the base of one metatarsal bone to the next. The plantar ligaments (fig. 224) are similar to the dorsal. The interosseous ligaments are short, transverse fibres between the contiguous rough lateral surfaces : they may be afterwards seen by forcibly separating the bones. Lateral union. The four outer bones touch one another laterally ; the second metatarsal lies against the internal and external cuneiforms ; and the fourth is in contact internally with the outer cunei- form. Those articulating surfaces are covered with cartilage ; and are provided with synovial mem- brane, which is derived from the sacs serving for the articulation of the same four metatarsal with the tarsal bones. The metatarsal bone of the great toe, like that of the thumb, is not united to the others at its base by any intervening bands. The digital ends of the five metatarsal bones are united by the transverse metatarsal ligament ; this has been described in page 624. Tarsal with metatarsal bones. These articulations resemble the like parts in the hand, as there is a separate joint for the great toe, and a common one for the four outer metatarsals. Articulation of the great toe. The articular ends of the bones are in- cased by a capsule, and are provided with an upper and a lower longitu- dinal hand to give strength to the joint : the lower band is placed between prolongations from tlie tendons of the tibialis anticus and peroneus longus. A simple synovial membrane serves for the articulation. The articular surfaces are oval from above down, curved inwards, and constricted in the middle ; that of the great toe is excavated, and the other is convex. Movement. There is an oblique movement of the metatarsal bone down and in and up and out, like that of the internal cuneiform with the sca- phoid bone ; and this will contribute some motion to inversion and ever- sion of the foot. The joint possesses likewise slight abdnctory and adductory movement. Articulation of the four outer toes. The tliree outer tarsal bones of the last row correspond with four metatarsals ; — the middle cuneiform be- ing opposite the second metatarsal bone, the external cuneiform touching that of the third toe, and the os cuboides carrying the two outer bones. Dorsal Ligaments Uni- TiNQ THE Tarsus to the Metatarsus, and the Me- tatarsal Bones to each other behinu (Bourgery). 650 DISSECTION OF THE LEG. The bones in contact are tipped with cartilage, and have longitudinal dor- sal, plantar, and lateral ligaments, with some oblique in the sole. The dorsal ligaments (fig. 226) are thin bands of fibres, which are more or less longitudinal as they extend from the tarsal to the metatarsal bones. Each metatarsal bone receives one ligament, except that of the second toe, to which there are three ; — the three bands to the second coming from all the cuneiform bones, one from each. The third bone obtains a liga- ment from the external cuneiform ; and the fourth and fifth have a fascicu- lus to each from the os cuboides. Plantar ligaments (fig. 224). There is one longitudinal band from each of the two outer cuneiform to the corresponding metatarsal bone ; but be- tween the cuboid and its metatarsal bones there are only some scattered fibres. The lateral ligaments are longitudinal ; they lie deeply between the bones, and are connected with the second and third metatarsals : they will be better seen by cutting the transverse bands joining the bases of the bones. To the bone of the second toe there are two bands, one on each side : — the inner is strong and is attached to the internal cuneiform ; and the outer is fixed into the middle or the outer cuneiform bone. The me- tatarsal bone of the third toe is provided with one lateral slip on its outer side, which is inserted above into the external cuneiform bone. Oblique plantar ligaments. A fasiculus of fibres extends across from the front of the internal cuneiform to the second and third metatarsals ; and from the external cuneiform there is another slip to the metatarsal bone of the little toe. Line of the articulation. The line of the articulation between the tarsus and metatarsus is zigzag, in consequence of the unequal lengths of the cuneiform bones. To open the articulation, the knife should be carried obliquely forwards from the tuberosity of the fifth to the base of the sec- ond metatarsal bone ; then about two lines farther back for the union of the second metatarsal with the middle cuneiform ; and finally, half an inch in front of the last articulation, for the joint of the internal cunei- form with the first metatarsal bone. Two synovial meinbranes are present in these tarso-metatarsal articula- tions. There is one between the cuboid and the two outer metatarsals, which serves for the adjacent lateral articular surfaces of the bones ; this is not always separate from the following. The second is placed in the joint between the external and middle cuneiforms with their metatarsal bones (third and second), and is an offset of the common synovial membrane belonging to the articulation of the scaphoid with the cuneiform bones (p. G48) : prolongations from it are furnished to the lateral articular surfaces of the second, third, and fourth (inner side) metatarsals. Articular surfaces. The osseous surfaces are not flat; for the metatar- sal bones are undulating, and the tarsal are uneven to fit into the others. Movement. From tlie wedge-shaped form of the metatarsal bones a slight movement from above down is obtainable; and this is greatest in the little toe and the next. In the little toe tliere is an abductory and adductory motion ; and a small degree of the same exists in the fourth toe. Dissection. All the superficial ligaments having been taken away, the interosseous ligaments of the tarsus and metatarsus may be seen by sepa- METATARSO-PHALANGEAL JOINTS. 651 ratinoj forcibly the cuneiform bones from one another and from tlie os cuboides ; the latter bone from the os scaphoides : and the bases of the metatarsals from one another. The dissector will find that, in using force, the bones will sometimes tear sooner than the ligaments. Metatarsus with phalanges. These are condyloid joints, in which the head of the metatarsal bone is received into the cavity of the phalanx. Each articulation has two lateral and an inferior ligament, as in the hand; and the joint is further strengthened above by an expansion derived from the tendons of the extensors of the toes. A distinct synovial mem- brane exists in each joint. In the articulation of the great toe there are two sesamoid bones, which are connected with the inferior and lateral ligaments. All these structures are better seen in the hand, where they are more distinct ; and their anatomy is more fully described with the dissection of that part. (See page oOl.) Surfaces of bone. The metatarsal bone has a rounded head, which is longest from above down, and readiest farthest on the plantar surface. On the end of the phalanx is a cup-shaped cavity. Movement. In this condyloid joint as in the hand, there is angular motion in four different directions, with circumduction. Flexion and extension. When the joint is bent the phalanx passes un- der the head of the metatarsal bone ; and when it is extended the phalanx moves back beyond a straight line with the metatarsal bone. A limit to flexion is set by the meeting of the bones, by the stretching of the fore part of the lateral ligaments, and by the extensor tendon ; and to extension, by the tightness of the inferior, and the hinder part of each lateral ligament, and by the flexor tendons. Lateral movemeyit. The phalanx passes from side to side across the end of the metatarsal bone. Its motion is checked by the lateral ligament of the side from which it moved, and by the contact with the other digits. Circumduction^ or the revolving of the phalanx over the rounded head of the metatarsal bone, is least impeded in the great toe joint ; but these movements in the foot are not so free as in the hand. AiiTicuLATiONS OF THE PHALANGES. There are two phalangeal joints to each toe, except the first. Ligaments similar to those in the metatarso-phalangeal joints, viz., two lateral and an inferior, are to be recognized in these articulations. The joint between the last two phalanges is least distinct ; and oftentimes the small bones are immovably united by osseous substance. These ligaments receive a more particular notice with the dissection of the hand (p. 302). A simple synovial membrane exists in each phalangeal articulation. Articular surfaces. In both phalangeal joints, the nearest phalanx presents a trochlear surface ; and the distal one is marked by two lateral hollows or cups with a median ridge. Movement. Only flexion and extension are permitted in the two pha- langeal joints of the toes, as in the hand. Inflexion the farther phalanx glides under the nearer; and in extension the two are brought into a straight line. The bending is checked by the lateral ligaments and the extensor ten- don ; and the straightening is limited by the inferior ligament and the flexor tendons. 652 ARTERIES OF THE LOWER LIMB, TABLE OF THE ARTERIES OF THE LOWER LIMB. f External pudic superficial epi- gastric superficial cir- cumflex iliac Profunda , Muscular Anastomotic Popliteal . Superior inferior. ^ External circumflex internal circumflex i first perforating second perforating , third perforating L terminal branch. Superficial deep branch. f Muscular upper internal . upper external . lower internal . lower external . azygos articular sural. Arterior tibial ■< I Posterior tibial i t, Ascending CRcending transverse. Muscular articular ascending . transverse . nutritious. final branches. articular articular Recurrent cutaneous muscular internal malleolar external malleolar articular tarsal three interos- seous, first interosseous' communicating to deep arch ' To great toe and half the next. metatarsal •^ digital Peroneal . nutritious to tibia communicating to peroneal -i articular Internal plantar external plantar Muscular nutritious to fibula anterior peroneal. Muscular plantar arch . r Muscu poster! I atinc N. B. The branches of the internal iliac artery which end in the limb, wi table of the arteries of the abdomen. Muscular posterior perfor- ■ S digital, for three toes and a half anterior perfor- ating. 1 be found in the VEINS OF THE LOWER LIMB 663 TABLE OF THE VEINS OF THE LOWER LIMB. Popliteal . Anastomotic Muscular Profunda Internal sa- 1^ pheuous . f Posterior tibial External plantar internal plantar articular conimunicatiug to saphenous nutritious Muscular plantar arch Posterior per- forating digital from three toes and j a half I anterior per- L forating. Anterior tibial External saphenous sural articular muscular. L peroneal Communicating to deep arch . interosseous metatarsal . . tarsal malleolar communicating to saphenous muscular recurrent. Branch from dor- sal arch of foot. plantar veins from outer side of OS calcis cutaneous in the leg. Anterior pero- neal muscular nutritious. Digital from great toe and half the next. Three interos- seous. Superficial deep branch. Terminal branch first perforating second perforating . third perforating External circumflex Nutritious, Ascending transverse desceuing L Internal clr.uMflex;^M_j^-l^V Branch from dorsal arch of the foot plantar veins about os calcis communicating with posterior and ante- rior tibial communicating with deep veins of thigh cutaneous from outer and inner parts of thigh external pudic superficial epigastric superficial circumflex iliac. 654 NERVES OF THE LOWER LIMB. TABLE OF THE NERVES OF THE LOWER LIMB. r 1. External cutaneous C Post < an ( bn Posterior and terior branches. 2. Obturator ■< Accessory to obturator externus to articulation superficial division deep divi- sion . ( to obtui i to pecti ( to hip j jxternus n \ Muscular . ' ( to plexus in rator trunk iieus oint. STo gracilis to abductor longus the thigh and artery To adductor brevis and magnus articular. 3. Anterior crural Superficial portion , deep part 4. branch ) rr„ !„*„„,, Muscular To sartorius to pectineus. middle cutaneous interuil cutaueous Muscular Anterior and inner branches. To rectus to vastus externus — articular to vastus internus and crureus — articular. internal S Branch to plexus over patella to saphenous ( leg and fot. fl. Small sciatic , Great sciatic f Inferior gluteal -; inferior pudendal * • ( cutiineous to glute teal region, thigh, and leg. 3. To gluteus 4. To qua- driitiis and gemelli . . 6. Superior gluteal f Articulation to hip to hamstrings. external popliteal internal popliteal Articular. Articular cutaneous l>eron<^al communicating recurrent articular musculo- J To peronei cutaneous ( cutaneous to foot and toes anterior tibial I Muscular < articular * ( cutaneous Muscular 18 to two toes. f Articular musculiir short saphenous f Muscular to flexors posterior tibial . internal plantar external plantar Cutaneous of the sole mus(;nlar four digital I communicating branch particular to the toes. Superficial part . . Muscular two digital articular To glutei to tensor vagina: femoris ■^-pp"' I "rut; BALL OF THE EYE. 655 CHAPTER X. DISSECTION OF THE EYE. The eyeball is the organ of vision, and is lodged in the orbit. Sup- ported in tliat hollow on a mass of fat, it is surrounded by muscles which impart movement to it ; and a thin membrane (tunica vaginalis oculi) isolates the ball, so as to allow free movement. Two lids protect the eye from external injury, and moderate the degree of light admitted into the interior ; and the anterior or exposed surface is covered by a mucous membrane (conjunctiva). Directions. In the absence of specimens of the human eye, the struc- ture may be learnt on the eye of the ox or pig. Let the student procure half a dozen eyes of the ox for the purpose of dissection. One or two shallow basins will be needed ; and some wax or tallow in the bottom of one, or in a deep plate, may be useful. Dissection. To see the general form of the ball of the eye, and the outer surface of the external coat, the attachments of the different muscles are to be taken away ; and the loose mucous membrane is to be removed from the front. The hall of the eye (fig. 227) is roundish in form and consists of two parts, which differ in appearance, viz., an opaque posterior portion, form- ing five-sixths of the whole, and a smaller transparent piece (cornea) in front ; these two parts are segments of different-sized spheres, the an- terior belonging to the smaller sphere. To the back of the eye the optic nerve is attached, rather to the inner side of tlie axis of the ball ; and around it nutritive vessels and the nerves enter. The antero-posterior diameter of the ball amounts to nearly an inch (■j^oths), but the transverse measures an inch. The organ of vision is composed of central transparent parts, with in- closing membranes or coats. The coats, posited one within another, are named sclerotic, choroid, and retina. Tiie transparent media in the in- terior are likewise three, viz., the lens, the aqueous humor, and the vitreous body. Dissection. To obtain a general idea of the structures to be dissected, the student may destroy one eyeball by cutting through it circularly : he will then be able to recognize the arrangement of the parts mentioned above, with their strength and appearance : and will be better prepared to follow the directions that are afterwards given. Fibrous coat of the eyeball. The outer casing of the eye consists of an opaque hinder part called sclerotic, and of an anterior transparent portion, the cornea. The SCLEROTIC (cornea opaca) is the firm, whitish, and opaque portion of the external stratum of the eyeball, which supports the more delicate structures within. Dissection. To examine the inner and outer surfaces of this layer it will be necessary to cut circularly with a scissors through the cornea close 656 DISSECTIOX OF THE EYE. to the sclerotic, and to remove the cornea from the front of the eyeball ; on piercing the cornea the aqueous fluid escapes from the containing chamber. The outer structures may be then abstracted from the interior of the sclerotic covering, and may be set aside with the cornea for subse- quent use. o. Outer or sclerotic coat, and d, the cornea. 6. Middle or choroidal coat. m. Ciliary ligament. s. Ciliary process. e. Ciliary muscle, and/, iris. c. Inuer c at of retina, continuous with the optic nerve behind, with a dark layer outside it. g. Lens. t. Suspensory ligament of the lens. h. Vitreous body. n. Hyaloid membrane. i. Posterior chamber. 0. Canal of Petit r. Sinus circularis iridis. 1. Optic nerve. The dotted line through the centre is the longitudinal axis of the ball. Diagram of a Horizontal Section of the Eyeball. The sclerotic tunic of the eye (fig. 227, a) is bell-shaped, and extends from the entrance of the optic nerve to the margin of the cornea, forming about five-sixths of the ball. At its back, and a little to the inner side of the centre (one-tenth of an inch), the optic nerve (I) is transmitted through an aperture in it: this opening decreases in size from without inwards, and is cribriform when the nerve is drawn out — the lattice-like condition being due to the bundles of fibrous tissue between the funiculi of the nerve. Small apertures for the passage of vessels and nerves are situate around the optic nerve ; and there are others for vessels at the front and centre of the ball. Anteriorly the sclerotic is continuous with the transparent cornea. On the outer surface this coat is smooth, except where the muscles are attached ; on the inner aspect it is of a dark color with flocculi of fine areolar tissue (membrana fusca) uniting it to the next coat, and with the ends of ruptured vessels and nerves. The sclerotic covering is thickest at the back of the eyeball, but it be- comes thinner and whiter about a quarter of an inch from the cornea, where it is visible as the '' white of the eye." Where it joins the cornea it becomes again somewhat thickened. In its substance near the union with the cornea is a small flattened venous space, the canal of Schlemm (sinus circularis iridis) (fig. 235, *■). Structure. The sclerotic coat is formed of layers of white fibrous tissue, collected into bundles, with a fine network of yellow or elastic fibres. In STRUCTURE OF CORNEA. 657 it are scattered nucleated cells, fusiform in shape, or possessing rays, and some with pigment. Though interlaced with one another, the fibres have rather a longitudinal direction towards the back of the ball, and a trans- verse one at the outer surface near the cornea. Only a few vessels ramify in the membrane, and end in capillaries with large meshes. The presence of nerves in it is a subject for inquiry. Cornea (fig. 227, d). This firm transparent membrane (cornea pellu- cida) forms about one-sixth of the eyeball, and measures about half an inch transversely, but rather less from above down. Its shape is circular ; though, when viewed in front, it appears largest in the transverse direc- tion, in consequence of the o{)aque sclerotic structure encroaching further on it above and below than on the sides. It is convex anteriorly, but concave posteriorly ; and it is ^^q^^^ *^ bV^^ of an inch in thickness. Its anterior is of rather less extent than its posterior surface. At the circumference it is thinned, and is blended with the sclerotic coat by continuity of tissue. Supported by the aqueous humor, it deflects the light transmitted to the eye, and influences by its greater or smaller convexity degrees of sight at different distances. After death it becomes flaccid from the transudation of the aqueous humor ; or, if the eye is im- mersed in water, it is rendered opaque by infiltration of the tissue by that fluid. Structure (fig. 228). The cornea is laminar in texture. It is constructed of a special thick part called cornea proper : in front of this is the conjunctiva, and behind is the membrane of Demours. The cornea proper, a (lamellated cornea), is made up of a series of superposed layers, about sixty in number, which join one an- other at numerous points, and cannot therefore be detached for any distance. The laminae are formed of fibres, continuous witli those of the sclerotic, and are flattened into membra- nous layers, arranged one over another. This structure possesses great toughness ; and its transparency is destroyed by disturbance of the position of the strata. The tissue when boiled gives cliondrin. Between the corneal layers are flattened irregular spaces, which join freely with one another ; and these intervals are occupied by nu- cleated stellate cells, called corneal corpuscles. In the healthy condition bloodvessels do not permeate it, but cease in capillary loops at the circumference. Nerves ramify in it, after los- ing their 0{)acity at the circumference ; they are said to form a subepithelial plexus on the anterior surface, from which varicose fibrils are prolonged amongst the pieces of the epithelium. The membrane at the back of the cornea (fig. 228) — membrane of Demours — consists of a basement layer covered by epithelium. Vertical Section A of tub Cornea. Basement layei- of cornea, with d, the caiijuuctivH.1 epithe- lium on it. Oblique fibres from it to the layers of the cornea. Basement lamina, with /, epi- thelium on it of the mem- brane of Demours. Surface view of the epithe- lium of the membrane of De- mours. 42 658 DISSECTION OF THE EYE. The basement layer^ E (posterior elastic lamina, Bowman), may be peeled off after a cut has been made across the cornea. It is dense, hard and elastic, measuring ^^Viy^^' *^ ^uVn^'^ ^^ ^^ \wc\\ in thickness ; it is very brittle, tearing readily when an attempt is made to separate it, and curls up when it is tree, with the attached surface innermost. Though very elastic, the structure is destitute of fibres. It is always transparent, and remains so after boiling, after the action of acids, and even after mace- ration. At the edge of the cornea this lamina breaks up into processes (" pil- lars of the iris") which blend with the outer margin of the iris, and with the sclerotic and choroid coats. A laminar epithelium, G, like that on serous membranes, clothes its free surface (fig. 228). The conjunctiva in front of the cornea (fig. 228) consists chiefly of epi- thelium cells, though there is a subjacent basement-like stratum. The basement layer, b (ant. elastic lamina, Bowman), is transparent, and only from ^oVo^^^ ^^ T^V^^^^ of an inch thick. It seems to be a some- what hardened piece of the cornea, without corneal spaces and corpuscles. From it fine threads are prolonged into the proper corneal layers, as in the woodcut. The epithelium, d, is formed of three or four layers of scales, the deeper being columnar, but the Superficial laminar in form. Vascular Coat of the Eyeball (fig. 231). The next covering is situate within the sclerotic, and is formed chiefly of bloodvessels and pig- ment cells : the muscles in the interior of the ball are connected with it. It is constructed of three parts : a posterior (choroid) corresponding with the sclerotic ; an anterior (iris) opposite the cornea ; and an interme- diate ring (ciliary muscle) on a level with the union of the sclerotic and cornea. Dissectio7i. Supposing the cornea of an eye cut through circularly, as before directed (p. 656), it will be necessary to take away the sclerotic to lay bare the choroid coat. With the point of the scalpel, or with a shut scissors, detach the fore part of the sclerotic from the front of the choroid by breaking through a soft whitish structure uniting them. Then, the eye being put into water, the outer coat is to be removed by cutting it away piece-meal with a scissors ; in taking it off the slender vessels and nerves beneath are to be preserved. The white ring around the eye in front, which comes into view during the dissection, is the ciliary muscle. For the purpose of obtaining an anterior view of the ciliary processes, which are connected with the anterior termination of the choroid coat, let the cornea be removed as before on another eyeball. Detach next the fore part of the sclerotic from the choroid ; and after two or three cuts have been made in it towards the optic nerve, the resulting flaps may be pinned out, so as to supj)ort the eye in an upright position. On removing with care the iris, taking it away from the centre towards the circumference, the ciliary processes beneath will be displayed. A posterior view of the processes may be prepared on another ball by cutting through it circularly with a scissors, about one-third of an inch behind the cornea, so that the anterior can be removed from the posterior half; on taking away the por- tion of the vitreous mass adherent to the anterior part of the ball, and wiping oflT the pigment from the back of the iris, the small processes will be made manifest. By means of this last dissection the interior of the choroid coat may be seen. CHOROIDAL COAT WITH ITS STRUCTURE, 659 If a vertical section is made of another eyeball, it will show the ciliary processes in their natural position, and will demonstrate the relative situa- tion of all the parts. This section, which is made with difficulty, should be attempted in water with a sharp large knife, and on a surface of wax or wood, after the cornea and sclerotic have been cut with a scissors. When the eye has been divided, the halves should remain in water. The CHOROID COAT (fig. 227, b) is a thin membrane of a dark color, and extends from the optic nerve to the fore part of the eyeball. When viewed on the eye in which the ciliary muscle is entire, it appears to ter- minate there ; but it may be seen in the other dissections to bend inwards behind that muscle, and to end in a series of projections (ciliary processes) behind the iris. This coverinfj is rather thicker and stronger behind than in front. It is supported at the bottom of the eyeball by its close connection to the sclerotic coat, and in front by the ciliary muscle. Posteriorly it is pierced by a round aperture for the passage of the optic nerve ; and anteriorly it is united with the iris. The outer surface (fig. 231) is flocculent, and is covered by the rem- nants of a thin membranous layer (membrana fusca, supra-choroidea) be- tween it and the sclerotic coat : on it may be seen small veins arranged in arches, and the ciliary arteries and nerves. The inner surface is smooth, and touches the thin dark pigmentary layer of the retina (fig. 227). Fiff. 229. Fig. 230. Inner Vikw of the Front op the Choroid Coat WITH its Ciliary Processes, and the Back of the Iris. a. Anterior piece of tlie choroid coat b. Ciliary processes. c. Iris. d. Spliincterof the pupil. e. Bundles of fibres of the dilator of the pupil. Pigment Cells of the Eyeball (Kolliker). a. Ramified pis^meut cells of the choroid coat. B. Front view of the hexagonal cells of the pigmentary membrane. The ciliary processes (fig. 229, b) are solid projections on the inner surface of the choroidal coat, and are arranged in a circle. About 85 in number, they lie side by side, and consist of larger and smaller eminences; at their inner extremity they are united by transverse ridges. About jV^^^ ^^ ^^ ^"^h ^^ length, they increase in depth internally, and projecting around the lens, bound circumferentially by their free ends the 660 DISSECTION OF THE EYE. space (fig. 227, t) (posterior chamber) behind the iris. In front tliey cor- respond with the back of the iris towards their inner end, but are se[)a- rated from it by pigment ; and behind tliey are closely connected with the membrane (t) (suspensory ligament) on the front of the vitreous body, and fit into hollows between eminences on the anterior surface of that membrane. Structure The choroid coat and its ciliary processes are formed prin- cipally of bloodvessels. Ramified pigment cells make up most of the rest of the coat. The stroma or web of the choroid is formed by the outrunners of spe- cial pigment cells (fig. 230, ^) which unite together, and construct, with fine areolar tissue, a fibrous network. Its meshes are finer towards the inner than the outer surface of the choroid. On the exterior and interior of the fibrous web the vessels ramify, with the following difiference in their arrangement. At the outer part (fig. 231) the larger branches of both arteries and veins are situate ; and the veins (A) form curves (vasa rorticosa) as they end in four or five chief eflTerent trunks. In the interspaces of the vessels are the ramified pigment cells (fig. 230-, ^), which contain a nucleus and molecular grains of dark-brown coloring matter. At the inner part of the choroid the vessels form a network of capillaries without pigment cells, and with meshes smaller than elsewhere, whose interstices are rather less towards the back than the front of the eyeball : this part of the choroidal coat is described sometimes as a separate layer {tunica Ruyschianri). In the ciliary processes there is a similar texture of ramified blood- vessels, though with larger capillary meshes than in the choroid ; and Fig. 231. a. Sclerotic, cut, and reflected. 6. Choroid coat. c. Iris. d. Circular. e. Radiating fibres of ciliary mus- cle. /. Ciliary nerves, and g, ciliary arteries Letwoen the two outer coats. 7t. Veins of the choroid coat. View op the Fro5t of trk Choroidal Coat and Iris— external surface (Zinn). the intermixed pigment cells lose their coloring matter towards the free ends. Ciliary muscle (fig. 231). In the eye from which the sclerotic coat has been removed, the white band of the ciliary muscle (e) {annulus CILIARY MUSCLE AND IRIS. 661 ilbidfjs), may be seen in its natural position outside the front of the choroid coat. It consists of unstriated fibres, and forms a grayish layer, about j^th of an inch wide, on the surface of the choroid coat (tig. 231, e) : there are two sets of fibres in it, radiating and circular: — The radiating or superficial, arise in front from tlie sclerotic coat (fig. 227, «), and the fibres of the posterior elastic layer of the cornea ; its fibres are directed backwards, and are inserted into the choroid coat oppo- site to, and rather behind the ciliary processes. The nerves to the iris pierce it. The circular fibres (ciliary ligament, fig. 231, d) are internal to the radiating, and form a ring about 4^^^^ of inch wide around the edge of the iris : they are not attached to the sclerotic or the cornea. Use. The radiating fibres of the muscle draw forwards the fore part of the choroid coat, and the ciliary processes, and thereby relax the suspen- sory ligament of the lens. The circular fibres are said to compress the outer ])art of the lens. The IRIS (fig. 231, c) is a vascular and muscular structure, about half an inch in diameter, whose vessels are continuous with those of the cho- roidal coat. Its position and connections may be observed in the different dissections that have been prepared. Placed w^ithin the ring of the ciliary muscle, it is suspended in front of the lens (fig. 227,/), and is pierced by an aperture for the transmission of the light. It is circular in form, is variously colored in different persons, and is immersed in the aqueous humor. By its circumference it is con- nected with the choroid coat and the posterior elastic layer of the cor- nea. The anterior surface is free in the aqueous humor, and is marked by lines converging towards the pupil. The posterior surface is covered with a thick layer of the pigment (fig. 227), to which the term uvea has been applied. The aperture in it (fig. 231 ) is the pupil of the eye ; this is slightly in- ternal to the centre, and is nearly circular in form, but its size is constantly varying (from ^^i\\ to ^ of an inch) by the contraction of the muscular fibres, according to the degree of light acting on the optic nerve. Membrane of the pupil. In the foetus the aperture of the pupil is closed by a vascular transparent membrane, wliich is attached to the edge of the iris, and divides into two distinct chambers the space in which the iris is suspended. The vessels in it are continuous behind with those of the iris and the case of the lens. About the eighth month the vessels become im- pervious, and at the time of birth only fragments of the structure remain. Structure (fig. 229). The stroma of the iris is composed of fibres of areolar tissue, arranged circularly at the circumference, and as radiating bundles passing like rays towards the pupil. In it are involuntary mus- cular fibres, both circular and radiating, together with pigment cells. Vessels and nerves ramify through the tissue. Muscular fibres. The sphincter of the pupil (fig. 229, d) is a narrow band about ^^i\i of an inch wide, whicli is close to the pupil, on the pos- terior aspect of the iris. The dilator of the pupil {e) is said to begin at the outer border of the iris, and to consist of bundles of fibres which join one another, and end internally in the sphincter. Action. Enlargement of the pupil is effected by shortening of the radi- ating fibres ; and diminution, by contraction of the circular ring. The 662 DISSECTION OF THE EYE. 232. movements of the iris are involuntary and regulate the admission of light into the ball. The pigment cells are spread out in the stroma, and are disposed also on both surfaces. In the stroma they are ramified and irregular, as in the choroid (fig. 230, ^), and may contain yellow, brown, or very dark pig- ment. On the front they are ovalish or rounded, but still ramified ; and behind, where there is a thick layer (uvea), the cells are round without outrunners, and are filled with granules. The color of the iris is dependent upon the tint, and the position of the pigment. The arteries of the iris (fig. 232, ^) have a looped arrangement : they are derived chiefly from the long and the anterior ciliary branches {d), but some come from the vessels of tlie ciliary processes. On arriving at the ciliary muscle the long ciliary arteries form a circle {e) around the margin of the iris ; from this loop other anasto- motic branches are directed towards the pupil, near which they join in a second arterial circle (/). From the last circle capillaries run to the pupil, and end in veins. The veins resemble the arteries in their arrangement in the iris, and ter- minate in the veins of the choroidal coat. The nerves of the iris (fig. 232, a) divide into branches, which commu- nicate, and extend towards the pupil; they are without dark outline, and their ending is not known. Ciliary Vessels and Nerves (fig. 231). Tlie ciliary arteries are offsets of the ophthalmic (p. 56), and supply the choroid, the ciliary processes, and the iris. They are classed into poste- rior and anterior, and two of the first set are named long ciliary ; but they will not be seen without a special injec- tion of the vessels of the eye. The posterior ciliary branches {g) pierce tlie sclerotic coat around and close to the optic nerve, and running forwards on the choroid, enter its substance at different points. Two of this set (long ciliary) are directed forwards, one on each side of the eyeball, and form a circle around the iris in the ciliary muscle, as be- fore explained. In the ball tiie outer one lies rather above, and the inner, rather below the middle. The anterior c i liar g iirteries, five or six in number, are smaller than the posterior, and arise at the front of the orbit from muscular branches (p. 56); they pierce the sclerotic coat about a line behind the cornea, su{)ply the ciliary [)rocesses, and join the circle of the long ciliary vessels. In inflammation of the iris these vessels are enlarged, and offsets of them form a rinnr around the cornea. Distribution of the Nkrvks and Ves- sels OF THE Iris. A. Half of the iris representing the nerves. a. Nerves entering the membrane, and uniting in a plexus, b, within it (Kiil- liker). B. Half of the iris with apian of the ves- sels. d. Ciliary arteries. e. Arch of vessels at the outer edge of the iris. /. Inner circle of vessels in the iris. g. Sphincter of the iris. CHAMBER OF AQUEOUS HUMOR. 663 The posterior ciliary veins (fig. 231) are commonly four in number, and the brandies entering these trunks form arches {h) (vasa vorticosa) on the surface of the choroid coat : they perforate the sclerotic layer at separate points, midway between the cornea and the optic nerve, and end in the ophthalmic vein. Anterior ciliary veins begin in a plexus within the ciliary muscle, and accompany the arteries through the sclerotic to end in the ophthalmic: they communicate with the venous space of the sinus circularis iridis (p. 656). The ciliary nerves (fig. 231,/) are derived from the lenticular ganglion, and the nasal nerve (p. 55). Entering the back of the eyeball with the arteries, they are continued with the vessels between the sclerotic and choroid, nearly as far as the ciliary muscle: at this spot the nerves send offsets to the cornea, and piercing the fibres of the ciliary muscle, enter the iris, but their manner of ending is unknown. Offsets from the nerves supply the ciliary muscle and the choroid. Chamber of the Aqueous Humor (fig. 227). The space between the cornea in front and the lens behind, in which the iris is suspended, contains a clear fluid named the aqueous humor. In the foetus before the seventh month this interval is separated into two by the iris and the pu- pillary membrane, but in /the adult it is only partly divided, for the two communicate through the pupil. The boundaries of the two chambers may be seen in the eye on which a section has been made. The anterior chamber is the larger part of the space; it is limited in front by the cornea, and behind by the iris. The posterior chamber (?) is a narrow interval behind the iris at the circumference, which is bounded in front by the iris; behind by the lens capsule, and by a piece of the membrane (suspensory ligament of the lens) on the front of the vitreous humor : and at the circumference by the ciliary processes. The aqueous humor is quite transparent, and consists nearly of pure water. A small quantity of chloride of sodium, with some extractive matter, is in solution in it. The Retina (fig. 227, c). This layer (tunica nervea) is in part con- tinous with the optic nerve, and is the most delicate of all the coats of the eyeball. On it the image of objects is formed in the bottom of the eye. Dissection. The retina can be satisfactorily examined only on an eye which is obtained within forty-eight hours after death. To bring it into view on the eyeball in which the choroid coat was dissected, the choroidal covering must be torn away carefully with two pair of forceps, whilst the eye is immersed in water or spirit. The retina is the most internal of the three concentric strata in the globe of the eye, and is situate between the choroid coat and the trans- parent mass (vitreous) in the interior. It is moulded upon, and supported by the vitreous body; and its form is that of a segment of a sphere, with a large aperture in front. Beginning behind at the optic nerve (fig. 227, c) the tliin layer extends forwards to tlie ciliary processes (their outer ex- tremities), where it ends in a wavy border — the oro. serrata. Where the retina ceases in front, a thin gray layer (ciliary part of the retina) composed of elongated nucleated cells, which are not nerve ele- ments, is continued on as far as the tips of the ciliary processes (fig. 235, j) on which it ends. The retina is of a pinkish gray color, and is semitransparent when 664 DISSECTION OF THE EYE Fig. 233. fresh, so that an image can be seen on it when the two external coats of the eye have been removed ; but it soon loses this translucency, and is moreover rendered opaque by the action of water and other substances. Its thickness is greater at the posterior tlian the anterior part of the eye- ball, being g^^th of an inch in the former, and y^o^^^ "^ ^^^^ latter situa- tion. On the outer surface of the dissected retina are some fine fragments of a structure (Jacob's membrane) to be noticed presently, which float in the fluid in which the preparation may be placed. The inner surface is smooth ; it is covered with folds in a preparation of an eye cut in two, but these are accidental, in consequence of the membrane having lost its proper sup- port. At the spot where the optic nerve ex- pands (poms opticus) is the central artery of the retina (fig. 233). In the anterior of the human eye, in the axis of the ball, is a slightly elliptical yellow part (fig. 233), j^th of an inch in diameter, which is named the yellow spot (limbus luteus of Sbmmerring). Almost in the centre of that spot is a minute hollow, the fovea centralis^ which appears black in consequence of tlie thinness of the wall allowing the dark pigment outside to be seen. Structure (fig. 234). In the retina are layers or strata with bloodvessels, viz., an in- ner ('), composed of nerve elements; an outer Q) (Jacob's membrane), formed of peculiar bodies; and an intermediate or granular layer {^)\ and outside all is a pigmentary stratum. Passing through the layers of the retina except Jacob's and the pigmentary, are minute threads — fibres of Miiller. The layer of nerve substance (^) is made up of nerve fibres, and of a molecular matrix containing different-sized nerve cells; these constituents have the following arrangement : — The tubules of the optic nerve (//,), having become solid in texture and gray in color from the absence of the white substance of Schwann, radiate in bundles from the end of the optic trunk, and communicate together to construct a thin web at the inner aspect of the nervous layer; this delicate network with lengthened meshes diminishes in strength as it is followed forwards. Outside the nerve fibres is a stratum of molecular material (/) with large pale pyriform and roundish nucleated nerve cells (_r/) with offsets ; this layer begins at the entrance of the optic nerve, and becomes thinner as it extends forwards. Around the optic nerve tiie cells are arranged in a layer one deep, but over the yellow spot they are about six or eight deep ; near the ora serrata they are scattered in clusters. An offset from eacli cell is supposed to join internally the nerve fibres ; and other oflsets are prolonged externally into the molecular material (/) and seem lost in it. The outer or columnar stratum (') (Jacob's membrane) consists of two different elements — rods and cones, which are arranged with their ends inwards and outwards. Objects on the Inner Surface OP THE Retina. In the centre of the ball is the yellow limbus luteus, here represenied by shading ; and in its middle the dark spot. To the inner side is the nerve, with its Hccompany- ing artery. (SOmmerring.) STRUCTUKE OF RETTNA 665 The rods (a) are elongated solid and grooved particles, which are pointed at the inner end, and are more numerous than the other elements ; from their inner ends fine threads (rod-fibres) are prolonged through tlie outer set of granules (c), and are there connected with elliptical transversely striated bodies. The cones (b) are shaped like a flask with a long neck, and have the larger end turned inwards : tiiey do not project so far out as the rods. AVhen viewed on the outer surface, tliey form large isolated swell- ings (m) amongst the ends of the rods, and at a deeper level. By their inner ends they are united with a pear-shaped cell (fig. 234) in the outer part of the granular layer, and are said to reach as far as the molecular material (d) between the two sets of granules. Fig. 234. 1. Columuar layer with rods a, and cones, 6. 2. Granular layer with outer, c, and inner granules, e, and intermediate non-granular part, d. 3. Nervous layer with g, nerve cells, and 7i, nerve fibres ; outside tho cells is a finely granular part,/, and in- side the fibres a limiting layer, i, formed by fibres of Miiller. On the left of the vertical section is an ideal plan of the connection of the several parts. Thus the nerve cell, ff, unites internally with nerve fibres, and externally with the inner granular layer ; and the inner granular layer is further joined by a thread (fibre of Miiller) to the outer granular layer. k. Microscopic api)earanceof the outer surface of the retina over the yellow spot, where there are only cones. I. Appearance of the retina near the yellow spot — a single circle of rods surrounding each cone. rn. Appearance of the middle of the retina, a large number of the rods surrou.iding each cone. In all three figures the larger rings represent the cones, and the smaller ones the rods seen endwise. Magnified Vertical Section of the Retina (altered from Kolliker). In the fresh state both are soft, clear, and homogeneous, with a glisten- ing appearance, but these characters are soon destroyed by water and other fluids : their structure is very uncertain. The granular layer (^) consists of innumerable rounded and ovalish bodies with nuclei, which are collected into two sets (c and e), with an intervening fine molecular material (d). In the inner set (e) tliere are several kinds of cells, wliose nature is unknown : two sets, which are oval and nucleated, are said to have this arrangement : One is connected with the fibres of Miiller ; and the other has a fibre at each end, like a bipolar ganglion-cell, wliich is continued outwards and inwards into the molecular material (d and /). In the outer set (c) two kinds of nucleated cells are to be recognized, which are connected with the fibres from the rods and cones in Jacob's layer. The cells of the rod-fibres, the most numerous, are elliptical, and marked by cross strias (Henle) (fig. 234). The cells of the cone-fibres are 66Q DISSECTION OF THE EYE. pyriform in shape, with the base turned to tlie cone, but are free from cross stripes. The intervening molecular portion (is, 547 of the vertebrae, 347 of tlio wrist, 296 Interclavicular ligament, 170 Jnteroolumnar fascia, 410 fibres, 410 Intercostal arteries, anterior branches, 240, 337, 419 posterior branches, 368, 384 artery, superior, (o) 78, (d) 338 muscle, external, 237, 342 internal, 238, 342 ' nerves, 237, 343, 416 cutaneous, anterior, 226 lateral, 226 veins, superior, 338 Intercosto-humeral nerve, (o) 226, (d) 256, 343 Intermediate tract, 383 Intermuscular septa of the arm, 258 of the foot, 615 of the thigh, 572 Internal cutaneous nerve of arm, 236, 250, 256 of thigh, (o) 573, (d) 556 saphenous vein, 557, 626 nerve, 596, 606, 627 Interosseous arteries of the foot, 631 of the hand, 280, 289 artery, anterior, 244, 271 posterior, 288 ligament of the arm, 295 of the leg, 642 muscles of the foot, 624 of the hand, 281 nerve, anterior, 271 posterior, 289 Interspinal muscles, 370 Intertransverse muscles, 165, 370 Intervertebral ganglia, 378 substance, 347 Intestinal arteries, 440 canal divisions, 433 structure, 456, 463 Intestine, large, 433, 461 small, 433, 456 Intra-spinal arteries, 384 veins, 385 Iris, 661 nerves of, 662 structure of, 661 vessels of, 662 Ischio-rectal fossa, 388 Island of Reil, 194 Isthmus faucium, 128 of the thyroid body, 120 of the uterus, 538 Iter a tertio ad quartum ventriculum, 206 ad infundibulum, 206 JACOB'S membrane, 664 structure, 664 Jacobson's nerve, (o) 112, (d) 678 Jejunum, connections of, 433 structure, 456 Joint, ankle, 642 INDEX 01 Joint — elbow, 293 great toe, 649 hip, 600 knee, 634 lower jaw, 90 shoulder, 290 thumb, 300 wrist, 296 Jugular ganglion, 111 vein, anterior, 71 external, 42, 62 internal, 82, 109 KIDNEY, 473 connections of, 435 structure, 475 vessels of, 476 Knee of the corpus callosum, 192 joint, 634 LABIA pudendi externa, 534 interna, 535 Labial glands, 133 artery, inferior, 40 nerve, 96 Labyrinth, 679 lining of, 681 membranous, 685 osseous, 679 Lachrymal artery, 45, 56 canals, 60 duct, 61 gland, 51 nerve, 52 point, 43, 60 sac, 61 Lactiferous ducts, 227 Lacunse of the urethra, 528 Lamina cinerea, 192 dentata, 204 reticularis, 685 spiralis cochlese, 683 Laminae of cerebellum, 213 of the lens, 669 Large intestine, connections, 433 structure and form of, 461 Laryngeal arteries, 158 nerve, external, 113 inferior, (o) 114, 331, (d) 158 superior, (o) 113, (d) 158 pouch, 156 Larynx, 151 aperture of, 128, 155 cartilages of, 159 interior of, 154 ligaments, 160 muscles, 151 nerves, 158 ventricle, 156 vessels, 158 Lateral column of the medulla, 183, 185 of the cord, 382 Lateral sinus, 28 ventricles, 200 Latissimus dorsi, 236, 356 Laxator tympani, 676 Leg, dissection of the back, 605 front, 626 Lens of the eye, 668 structure of, 669 Lenticular ganglion, 55 Levator anguli oris, 38 scapulae, 358 ani, 390, 501 glandulae thyroidese, 120 labii superioris, 38 alaeque nasi, 35 inferioris, 38 palati, 129 palpebrae superioris, 53 Levatores costarum, 373 Lieberkiihn's crypts, 459 Ligament of the lung, 307 Ligaments of the bladder, 503, 504 of the larynx, 261 of the ovary, 512 of the pinna, 47 of the uterus, 510 Ligament, acromio-clavicular, 246 alar of the knee, 637 annular, anterior of the ankle, 628 external of the ankle, 628 internal of the ankle, 614 anterior of the wrist, 282 posterior of the wrist, 282, 289 anterior, special, of ankle, 643 of elbow joint, 283 of knee joint, 636 of wrist joint, 296 of carpus, 298 astragalo-scaphoid, 645 alto-axoid, anterior, 167 posterior, 167 transverse, 169 . calcaneo-astragaloid, 644 cuboid, 646 scaphoid, 645 capsular of the hip, 600 of the knee, 634 of the shoulder, 290 of the thumb, 300 carpal, dorsal, 297 palmar, 297 carpo-metacarpal, 300 chondro-sternal, 345 common, anterior, of vertebrae, 346 common, posterior, 347 conoid, 246 coraco-acromial, 246 clavicular, 245 humeral, 291 costo-clavicular, 171 coracoid, 232 702 INDEX. Ligament — costo-transverse, anterior, 345 middle, 345 posterior, 345 vertebral, 344 xiphoid, 346 cotyloid, 602 crico-thyroid, 161 crucial, 637 deltoid, 643 dorsal of the carpus, 298 of Gimbernat, 416, StJO glenoid, 290 ilio-femoral, 600 lumbar, 546 interarticular, of the clavicle, 171 of the hip, 602 of the jaw, 91 of the knee, 638 of the pubes, 546 of the ribs, 344 of the wrist, 296 interclavicular, 170 interosseous of astragalus and os calcis, 637 of carpus, 298 of cuneiform bones, 648 of metacarpal bones, 299 of metatarsal bones, 649 of radius and ulna, 294 of the scaphoid and cuboid, 648 of the tibia and fibula, 642 Interosseous, inferior, of the tibia and fibula, 642 interspinal, 350 intertransverse, 350 intervertebral, 347 lateral, external of the ankle, 643 internal, 643 external of the carpus, 298 internal, 298 external of the elbow, 293 internal, 293 phalangeal of the foot, 651 of the hand, 308 external of the jaw, 90 internal, 91 external of the knee, 634 internal, 634 external of the wrist, 296 internal, 296 long plantar, 647 metacarpal, dorsal, 299 palmar, 299 metatarsal, dorsal, 649 plantar, 649 mucous, 637 obturator, 546 occipito-atloid, anterior, 168 posterior, 168 occipito-axoid, 1(58 odontoid, 169 orbicular of the radius, 294 of the patella, 636 Ligament — palmar of carpus, 298 peroneo-tibial, 641 of Poupart, 411, 559 posterior of ankle, 643 of carpus, 298 of elbow, 293 of knee, 636 of scapula, 247 of wrist, 296 proper of the scapula, 246 pubic anterior, 546 superior, 547 round of the hip, 602 round of the radius and ulna, 295 sacro-coccygeal, anterior, 544 posterior, 544 sacro-iliac, anterior, 544 posterior, 544 sacro-sciatic, large, 545, 592 small, 545, 592 sacro-vertebral, 544 of the scapula, anterior, 247 posterior, 247 sterno-clavicular, 170 stylo-hyoid, 106 maxillary, 91 subpubic, 547 supraspinous, 350 suspensory of penis, 408 tarso-metatarsal, dorsal, 650 lateral, 650, plantar, 650 thyro-arytaenoid, 162 epiglottidean, 162 hyoid, 161 tibio-tarsal, 643 transverse of the atlas, 170 of the fingers, 273 transverse of the hip, 602 of the knee, 639 of metacarpus, 280 of metatarsus, 624 of the toes, 615 trapezoid, 246 triangular of the abdomen, 411 of the urethra, 396 of Winslow, or posterior, 636 Ligamentum arcuatum, 486 denticulatum, 376 du-ctus arteriosi, 325 latum pulmonis, 307 longum plantae, 647 mucosum, 637 nuchse, 356 patellae, 636 spirale, 683 subflavum, 34 teres, 602 Limb, upper, 224 lower, 552 Limbus cochleae, 683 luteus, 664 Limiting membrane of retina, 666 INDEX 703 Linea alba, 410 semilunaris, 416 Liiieae trans versae, 415 Lingual artery, 85, 101 glands, 150 nerve, 97, 101, 150 vein, 101 Lingualis muscles, 149 Lips, 133 Liquor Cotunnii, 681 Lithotomy, parts cut, 399 Liver, 466 connections of, 435 ligaments, 438 structure, 469 vessels, 471 Lobes of the cerebellum, 213 of the cerebrum, 193 Lobules of the testis, 482 of the liver, 469 Lobulus auris, 46 oaudatus, 467 quadratus, 467 Spigelii, 467 Locus niger, 191 perforatus anticus, 192 posticus, 191 Longissimus dorsi, 363 Longitudinal fibres of the brain, 210 fissure of the liver, 468 sinus, inferior, 27 superior, 25 Longus colli muscle, 163 Lumbar aponeurosis, 357 arteries, 498 anterior branches, 498 posterior branches, 368 ganglia, 497 glands, 495 nerves, anterior branches, 495 posterior branches, 368, 384 plexus, 496 region of the abdomen, 431 veins, 492, 498 Lumbo-sacral nerve, 495 Lumbricales of the foot, 620 of the hand, 277 Lungs, 333 connections, 308 physical characters, 334 structure, 334 vessels and nerves, 335 Lymphatic duct, 119, 340 right, 79, 340 Lymphatics of the arm, 250 of the axilla, 230 of the groin, 407, 554 of the lungs, 336 of the mesentery, 441 of the neck, 67 of the pelvis, 520 of the popliteal space, 597 of the thorax, 339 Lyra, 203 MALLEOLAR arteries, 637 Malleus, 674 muscles of, 676 Malpighian corpuscles of spleen, 466 of kidney, 475 Mamillse of the kidney, 474 Mamma, 226 structure of, 227 Mammary artery, internal, (o) 77, (c) 239, 330, 419 gland, 226 Masseter muscle, 87 Masseteric artery, 94 nerve, 95 Mastoid cells, 672 Maxillary artery, internal, 93, 142 nerve, inferior, (o) 32, (d) 94 superior, 32, 104 vein, internal, 94 Meatus auditorius externus, 670 nerves of, 671 vessels of, 671 urinarius, 527 Meatuses of the nose, 134 Meckel's ganglion, 139 Median basilic vein, 249 cephalic vein, 249 nerve, (o) 236, (c) 255, (d) 269, 274 vein, 249, 261 Mediastinal arteries, 239, 337 Mediastinum of thorax, 307 Mediastinum of testis, 481 Medulla oblongata, 182 gray matter of, 186, 317 Medulla spinalis, 380 Medullary substance of the kidney, 474 velum, anterior, 215 posterior, 215 Meibomian follicles, 44 Membrana basilaris, 683 granulosa, 540 pigmenti, 666 pupillaris, 661 reticularis, 685 sacciformis, 297 tympani, 673 Membrane of Corti, 684 of Demours, 657 hyaloid, 667 Jacob's, 664 of the labyrinth, 681 of Reissner, 684 Membranes of the brain, 24, 172 of spinal cord, 374 Membranous labyrinth, 685 part of the cochlea, 683 of the urethra, 527 Meningeal artery, anterior, 29 middle, 29, 93 posterior, 29, 86, 174 small, 29, 93 nerves, 30 Mesenteric artery, inferior, 441 superior, 439 704 INDEX. Mesenteric — glands, 441 plexus inferior, 443 superior, 443 vein, inferior, 443 superior, 441 Mesentery, 438 Meso-cjecuin, 438 colon left, 438 right, 438 transverse, 438 rectum, 438, 503 Metacarpal arteries, 269, 289 Metatarsal artery, 632 Mitral valve, 320 Modiolus of the cochlea, 682 Molar teeth, 133 glands, 42 Mons Veneris, 534 Motor oculi nerve, (o) 180, (c) 30, (d) 54, 57 Mouth, cavity of, 132 Mucous ligament, 637 Multifidus spinse muscle, 370 Muscularis mucosae, 457 Musculi papillares, 318, 320 pectinati, 316, 319 Musculo-phrenic artery, 239, 490 cutaneous nerve, (o) 633, (d) 626 of the arm, (o) 234, (c) 256, (d) 259 spiral nerve, 236, 259 Muse, abductor digiti minimi, 278 pedis, 616 indicia, 280 pollicis, 277 pedis, 616 accessorius pedis, 620 ad sacro-lumbalem, 362 adductor brevis, 577 digiti minimi, 279 longus, 576 magnus, 579, 599 policis manus, 278 pedis, 621 anconeus, 285 anti-tragicus, 46 arytsenoideus, 153 attollens aurem, 18 attrahens aurem, 18 azygos uvulae, 131 biceps femoris, 597, 635 flexor, cubiti, 252, 271, 291 brachialis anticus, 256, 271 buccinator, 39 cervicalis ascendens, 363 chondro-glossus, 148 ciliaris, 660 circumflexus palati, 129 coccygeus, 501 complexus, 364 compressor naris, 35 constrictor inferior, 124 Muse, constrictor — medius, 124 * superior, 124 urethrje, 397, 403 coraco-brachialis, 252 corrugator cutis ani, 389 supercilii, 37 cremastericus, 412 crico-arytaenoideus lateralis, 153 posticus, 152 thyroideus, 152 deltoides, 242 depressor anguli oris, 39 epiglottidis, 154 labii inferioris, 38 alse nasi, 36 diaphragm a, 484, 343 digastricus, 82 dilatator naris, 35 pupillae, 661 ejaculator urinae, 394 erector clitoridis,'403 penis, 394 spinas, 362 extensor carpi radialis brevior, 284 longior, 284 ulnaris, 285 digiti minimi, 285 digitorum brevis pedis, 632 communis, 285 longus pedis, 629 indicis, 288 ossis metacarpi pollicis, 287 pollicis proprius, 629 primi internodii pollicis, 287 secundi internodii pollicis, 287 flexor accessorius, 620 brevis digiti minimi, 278 pedis, 620 carpi radialis, 264, 282 ulnaris, 265 digitorum brevis pedis, 616 longus pedis, 610, 619 profundus, 270, 276 sublimis, 266, 276 pollicis longus, 270, 277 pedis, 610, 620 pollicis brevis, 278 pedis, 621 gastrocnemius, 608 gemellus inferior, 589 superior, 589 genio-hyo-glossus, 100, 149 hyoideus, 100 glosso-pharyngeus, 149 gluteus maximus, 583 medius, 585 minimus, 586 gracilis, 574 helicis major, 46 minor, 46 hyo-glossus, 99, 182 iliacus, 493, 580 ilio-costalis, 362 INDEX 705 Muse. — indicator, 288 infra-costalis, 342 infra-spinatus, 244 intercostales externi, 237, 342 interni, 238, 342 interossei maims dorsales, 281 palmares, 281 pedis dorsales, 625 plantares, 624 interspinal es, 370 intertransversales, 165, 370 kerato-cricoideus, 153 latissimus dorsi, 236, 356 laxator tympani, 676 levator anguli oris, 38 scapulae, 358 ani, 390, 501 glandulse thyroidese, 120 labii superioris, 38 alse nasi, 36 inferioris, 38 palati, 129 palpebrse, 53 uvulae, 181 levatores costarum, 373 linguales, 149 longissimus dorsi, 363 longus colli, 163 lumbricales manus, 277 pedis, 620 mallei externus, 676 internus, 676 massetericus, 87 multifidus spinse, 371 mylo-hyoideus, 98 obliquus abdominis externus, 409 internus, 411 capitis inferior, 369 superior, 369 oculi inferior, 59 superior, 53 obturator externus, 580,591 internus, 543, 590 occipito-frontalis, 18 omo-hyoideus, 72, 359 opponens digiti minimi, 279 pollicis, 278 orbicularis oris, 37 palpebrarum, 36 orbitalis, 60 palato-glossus, 130, 148 pliaryngeus, 130 palmaris brevis, 272 longus, 265 pectineus, 576 pectoralis major, 230, 231 minor, 231 peroneus brevis, 633 longus, 625, 633 tertius, 629 plantaris, 609 platysma myoides, 62, 67 popliteus, 610, 635 45 Muse. — pronator quadratus, 271 radii teres, 264 psoas magnus, 492, 580 parvus, 493 pterygoideus externus, 89 internus, 90 pyramidalis abdominis, 416 nasi, 34 pyriformis, 542, 587 quadratus femoris, 590 lumborum, 494 rectus abdominis, 415 capitis anticus major, 164 minor, 165 lateralis, 115 posticus major, 369 minor, 369 femoris, 570, 587 oculi externus, 57 inferior, 57 internus, 57 superior, 53 retrahens aurem, 18 rliomboideus major, 358 minor, 358 risorius Santorini, 39 rotatores dorsi, 369 sacro-lumbalis, 362 salpingo-pharyngeus, 126 sartorius, 566 scalenus anticus, 75 medius, 75 posticus, 75 semi-spinalis colli, 370 dorsi, 370 semi-membranosus, 598, 636 semi-tendinosus, 597 serratus magnus, 236 posticus inferior, 360 superior, 360 soleus, 608 sphincter ani externus, 389 internus, 389 pupillse, 661 vaginae, 402 spinalis dorsi, 362 splenius capitis, 361 colli, 361 stapedius, 676 sterno-cleido-mastoideus, 71 hyoideus, 72 thyroideus, 73 stylo-glossus, 100, 148 hyoideus, 83 pliaryngeus, 106 subaneoneus, 259 subclavius, 232 subcrureus, 572 subscapularis, 241 supinator radii brevis, 288 longus, 284 supraspinatus, 247 temporalis, 20, 88 706 INDEX Masc. — tensor palati, 129 tarsi, 59 tympani, 676 vaginae femoris, 570 teres major, 245 minor, 245 thyro-arjtaenoideiis, 153 hyoideus, 73 tibialis anticus, 628 posticus, 612, 625 trachelo-mastoideus, 363 tragicus, 46 trans versalis abdominis, 413 colli, 363 transversus auris, 47 linguae, 149 pedis, 621 perinaei, 395, 403 alter, 395 profundus, 398, 403 trapezius, 354 triangularis sterni, 238 triceps extensor cruris, 570 cubiti, 258 vastus externus, 571 internus, 571 zygomaticus major, 39 minor, 39 Mylo-hyoid artery, 93 muscle, 98 nerve, 96 VfARES, 42, 126 ll Nasal artery, internal, 57, 142 artery, lateral, 40 cartilages, 42 duct, 61 fossae, 134 nerve, (d) 54, (c) 141, (o) 57 Naso-palatine nerve, 140 artery, 142 Neck, anterior triangle of, 69 posterior, 63 dissection of, 61 Nerve of Jacobson, 112, 678 Wrisberg, (o) 236, (d) 251, 256 Nerve to the inferior gemellus and quad- ratus, 589 latissimus, 236 levator anguli scapulae, 80 obturator internus, 518, 590 pectineus, 573 pterygoid, internal, 145 pyriformis, 518 rhomboid muscle, 80, 359 scaleni, 80 serratus muscle, (o) 79, (d) 236 subclavius, 80 superior gemellus, 589 tensor palati, 145 tympani, 145 vaginae femoris, 574 Nerve — teres major, 236 minor, 245 vastus externus, 573 internus, 573 Nervous tunic of eyeball, 663 Nerv. abducens, (o) 180, (c) 32, (d) 57 accessorius obturatorius, 497, 577 spinalis, 114, 181, 356 acromiales, cutanei, 80, 242 articulares poplitei, 596 articularis poplitei obturatorius, 577, 596 auditorius, 181, 680 auriculares anteriores, 23 auricularis magnus, 23, i)6 pneumogastricus, (o) 113, (d) 679 inferior, 96 posterior, 23, 48 auriculo-temporalis, 23, 90 buccales, 50, 95 buccinatorius, 95 cardiacus inferior, (o) 117, 122, (d) 332 medius, (o) 117, 122, (d) 332 pneumogastrici, 114, 331, (d) 332 superior, (o) 11 , 122, (d) 314, 333 cervicales nervi facialis, 68 rami anteriores, 79, 165 posteriores, 165, 365 cervicalis superficialis, 66, 68 cervico-facialis, 50 chorda tympani, 97, 144 ciliares ganglii ophthalmici, 55, 663 ciliaris nasalis, 54, (d) 663 circumflexus, 236, 244 claviculares cutanei, 66 coccygealis, 373, 518 cochlearis, 687 communicans fibularis, 606 corporis bulbosi, 399 cruralis, (o) 497, (d) 572 cutanei abdominis, anteriores, 407 laterales, 406 cutaneus externus brachialis, (o) 235, (c) 256, (d) 262 lumbalis, (o) 497, (d) 556 musculo-spiralis, 250, 259, 262 internus brachialis, major, 236, 256, 261 minor, 236, 251, 256 femoris, (d) 556, (o) 573 musculo-spiralis, 250, 259 medius femoris, (o) 573, (d) 556 musculo-cutaneus, 250 palmaris, 269, 272 plantaris, 613 radialis, 262 dorsalis mantis, 269 INDEX TOT Nerv. — dentales posteriores, 104 dental is, anterior, 104 inferior, 96 descendens noni, 83, 115 diaphragmaticus, (o) 80, (d) 330 digastricus 48 digitales median!, 275 plantares, 619 radiales, 262 ulnares, 274 dorsales, rami anteriores, 239, 343, 378 posteriores, 367, 378 dorsalis penis, 399, 408 ulnaris, 262, 269 facialis, 47, 143 frontalis, 52 genito-cruralis, 497, 556 ramus femoralis, 556 genitalis, 418 glosso-pharyngeus. 111, 151, 181 glutei infer lores, 588 gluteus superior, 496, 586 gustatorius, 97, 101, 151 haraorrlioidales superiores, 443 hseraorrhoidalis inferior, 390 hypoglossus, 83, 102, 115, 151 ilio-liypogastricus, 416, 496, 582 inguinalis, 416, 497, 55^ incisorius, 96 infra-maxillares faoiales, 50, 68 orbitales nervi facialis, 49 orbitalis, 60, 104 trochlearis, 54 intercostales, 239, 416 intercosto-cutanei anteriores, 226, 406 laterales, 206, 406 humeralis, 254, 226, 251 interosseus anticus, 271 posticus, 289 labialis, 96 lachrymalis, 52 laryngeus externus, 114 inferior, (o) 331, (d) 114, 158 superior, (o) 113, (d) 158 lumbales, rami anteriores, 495 posteriores, 369, 384 lumbo-sacralis, 496 malares nervi facialis, 48 massetericus, 95 maxillaris inferior, (o) 32, (d) 94 superior, 31, 104 medianus, 236, 255, 269, 274 meningei, 30 nioUes, 116 motor oculi, (o) 180, (c) 32, (d) 54, 57 musculo-cutaneus brachii, 236, 256, 262 cruris, 633, (d) 626 musculo-spiralis, (o) 236, (d) 259 mjlo-hyoideus, 9Q Nerv. — nasalis, (o) 51, (d) 54, 57, 141 naso-platinus, 141 obturatorius, (o) 497, (d) 577 articularis, 577, 596 occipitalis, major, 366 minor, (d) 24, (o) 66 cesopliageales, 331 olfactorius, (c) 30, (d) 136, (o) 178 ophthalmicus, 32, 51 opticus, 57, 137, 179, 207 orbitalis, (d) 60, (o) 104 palatinus magnus, 140 medius, 141 minor, 141 palpebrales, 45, 104 pulmaris cutaneus, 272 ulnaris profundus, 280 superficialis, 274 patellaris, 557, 573 perforans Casserii, (o) 236, (c) 256, (d) 262 perinseales superficiales, 391, 394 peronealis, 596 petrosus superficialis externus, 33 magnus, 33, 141 parvus, 33, 678 pharyngei, 112, 117 pharyngeus, 113 phrenicus, 80, 330 plantaris externus, 619 profundus, 624 internus, 624 pneumo-gastricus, 112, 181, 330, 452 popliteus externus, 596 internus, 596 portio dura, 47, 142, 180 mollis, (o) 181, (d) 687 pterygoidei, 95 pterygoideus internus, 95, 145 pudendus inferior, (o) 589, (d) 394, 407 internus, (o) 518, (d) 391, 399, 408 pulmonares anteriores, 331 posteriores, 331 radialis, 263, 270 recurrens, 114, 331, (d) 158 articularis, 633 sacrales, rami anteriores, 518 posteriores, 372, 581 saphenus externus, 606, (d) 627 internus, (o) 573, (d) 557, 573, 627 sciaticus magnus, 519, 589. 599 parvus, 519, 582, 584, 599 spermatici, 443 spheno-palatini, 104 sj^lanchnicus major, (o) 342, 452 minor, (o) 342, (d) 452 minimus, (o) 342, (d) 452 splenici, 451 stylo-hyoideus, 48 708 INDEX Nerv. — suboccipital is, ramus anterior, 115 posterior, 368 subscapulares, 236 superficialis cordis dexter, (o) 117 (d) 332 sinister, (o) 122, (d) 314 supraraaxillares nervi facialis, 48 orbitalis, 22, 51 scapularis, 80, 248, 359 trochlearis, 23, 52 sympatheticus abdominis, 443, 450, 497 cervicis, 115 pelvis, 519 thoracis, 331, 341 temporales nervi facialis, 48 profundi, 95 superficiales, (d) 23, (o) 48 teraporo-facialis, 48 malaris, 60, 104 thoracici, anteriores, 236 laterales, 226 thoracicus posterior, 80, 236 tibialis anticus, 627, (d) 632 posticus, 613 trigeminus, 31, 180 trochlearis, 31, 51, 180 tympanicus, (o) 112, (d) 678 ulnaris, 255, 269, 274 uterini, 520 vaginales, 520 vestibularis, 687 vidianus, 141 Ninth nerve, (o) 182, (c) 115, (d) 83, 102 Nipple of the breast, 226 Nodule, 212 Nose, cartilages, 42 cavity of, 133 meatuses of, 134 nerves and vessels of, 139, 141 Nuclei of medulla oblongata, 187 Nucleus caudatus, 203 lenticularis, 203 Nutritious artery of fibula, 613 of femur, 578 of humerus, 254 of tibia, 612 Nymphse, 534 OBLIQUUS abdominis externus, 409 internus, 411 capitis inferior muscle, 369 superior muscle, 369 oculi inferior, 59 superior, 53 Obturator artery, (o) 515, (d) 580 fascia, 500 ligament, 546 membrane, 54b muscle, external, 580, 591 internal, 543, 590 Obturator nerve, (o) 497, (d) 577 Occipital artery, (o) 86, (c) 368, (d) 21 lobe, 194 vein, 21, 86 sinus, 27 Occipito-atloid articulation, 168 ligaments, 168 Occipito-axoid ligaments, 169 frontalis muscle, 18 Odontoid ligaments, 169 (Esophagus, connections of, 121, 339 structure, 131, 339 (Esophageal arteries, 337, 447 nerves, 331 opening of diaphragm, 487 Olfactory bulb, 179 cells, 137 nerve, (o) 178, (d) 138 region, 137 Olivary body, 183, 185 commissure, 186 fasciculus, 186, 189, 208 Omentum, great, 437 small, 437 splenic, 437 Omo-hyoid muscle, 72 Ophthalmic artery, 33, 56 ganglion, 55 nerve, (o) 31, (c) 32, (d) 51 vein, 57 Opponens pollicis muscle, 278 Optic commissure, 179 nerve, (o) 179, 207, (c) 57, (d) 664 thalamus, 207, 211 tract, 179 Ora serrata, 663 Orbicular ligament of the radius, 294 Orbicularis oris, 37 palpebrarum, 36 Orbit, 50 muscles of, 53, 57 nerves, 51 periosteum of, 50 vessels, 56 Orbital branch of nerve, (d) 60, (o) 104 Organ of Corti, 684 of Giraldes, 483 Orifice of the urethra, 535 of the uterus, 535 of the vagina, 535 Os hyoides, 159 Ossicles of the tympanum, 674 Os tincse, 537 Os uteri externum, 537 Otic ganglion, 144 Otoliths, 686 Outlet of the pelvis, 386 Ovaries, 512, 539 appendage to, 540 arteries of, 490, 516 Ovicapsule, 540 INDEX 709 Ovisacs, 540 Ovum, 539 PALATE (soft), 128 Palatine, arteries, superior, 143 artery, inferior, 86 nerve, external, 141 large, 140 small, 141 Palato-glossus, 130, 148 Palato-pharyngeus, 130 Palm of the liand, 272 cutaneous nerves of, 272 Palmar arch, deep, 280 superficial, 273 nerve of the ulnar, deep, 280 superficial, 274 cutaneous nerves, 272 fascia, 272 Palmaris brevis muscle, 272 longus muscle, 265 Palpebrse, 43 Palpebral arteries, 45, 57 ligament, 44 nerves, 45 veins, 45 Pancreas, 464 connections, 446 structure of, 464 Pancreatic arteries, 447 duct, 457, 465 veins, 448 Pancreatico-duodenal arteries, 440, 448 Papilla lachrjmalis, 45 PapilLie of the tongue, 146 Parietal lobe, 194 Parovarium, 540 Parotid gland, 41 arteries, 86 Patellar nerve, 573 plexus, 557 Pectineus muscle, 576 Pectoralis major muscle, 230, 231 minor muscle, 231 Peduncle of the cerebellum, inferior, 215 middle, 215 superior, 215 of the cerebrum, 190, 211 of the pineal body, 208 Peduncular fibres, 207 Pelvis, female, dissection of, 509 male, 499 dissection of, 499 Pelvic cavity, 499 fascia, 500 plexus, 519 Penis, 508 integument of, 407 structure of, 529 vessels of, 532 Peptic glands, 455 Perforating arteries of the femoral, 578, 599 of internal mammary, 239 of the palm, 280 of the sole, 623, 632 Perforans Casserii nerve, (o) 236, (c) 256, (d) 262 Pericardium, 310 vessels of, 311, 337 Perilymph, 681 Perinseum, female, 400 male, 386 Perinaeal artery, superficial, 393 fascia, deep, 396 superficial, 392 nerves, superficial, 391, 393, 399 Periosteum of the orbit, 50 Peritoneal prolongation on the cord, 417 Peritoneum, 435 of female pelvis, 510 of male pelvis, 504 Peroneal artery, 613 anterior, 613 nerve, 596 Peroneus brevis muscle, 633 longus muscle, 625, 633 tertius muscle, 629 Peroneo-tibial articulations, 641 Pes hippocampi, 204 Petrosal ganglion. 111 sinus, inferior, 29 superior, 29 nerve, large, 33, 141 small, 33, 678 external, 33 Peyer's glands, 459 Pharynx, 124 interior, 126 muscles of, 124 openings of, 126 Pharyngeal ascending artery, 109 nerve, 113 vein, 112 Pharyngeo-glossal muscle, 149 Phrenic artery, 330, 490 nerve, 80, 330 Pia mater of the brain, 173 of the cord, 376 Pigmentary layer of retina, 666 Pigment cells of choroid, 660 iris, 662 Pillars of the abdominal ring, 410 of the fornix, 208 of the iris, 658 of the soft palate, 128 Pineal body, 208 Pinna, or auricle of the ear, 45 Pituitary body, 192 Plantar aponeurosis, 615 arch of tlie artery, 623 arteries, 617, 623 ligament, long, 647 nerve, external, 619, 624 internal, 619 45' 710 INDEX. Plantaris muscle, 609 Platysma myoides muscle, 62, 67 Pleura, 307 Plexus, aortic, 443 brachial, 79, 235 cardiac, superficial, 314 deep, 332 carotid, 33 cavernous, 33 cervical, 80 posterior, 367 clioroides cerebri, 205 cerebelli, 218 coeliac, 451 coronary, anterior, 314 posterior, 314 coronary of the stomach, 451 diaphragmatic, 451 gul«, 331 hepatic, 451 haemorrhoidal, 520 hypogastric, 444 lumbar, 496 mesenteric, inferior, 443 mesenteric, superior, 443 oesophagean, 331 ovarian, 520 patellar, 557 pelvic, 519 pharyngeal, 113 prostatic, 520 pterygoid of veins, 94 pulmonary anterior, 331 posterior, 331 renal, 451 supra, 451 sacral, 518 solar, 451 spermatic of nerves, 443 of veins, 492 splenic, 451 tympanic, 678 uterine, 520 vaginal, 520 vesical, 520 vertebral, 117, 166 Plica semilunaris, 45 Pneumogastric nerve, (o) 181, (d) 112, 181, 330, 452 Pons Tarini, 191 Varolii, 188 structure of, 184 Popliteal artery, 594 glands, 597 nerve, external, 596 internal, 596 space, 593 vein, 596 Popliteus muscle, 610, 635 Portal veins, 448 Portio dura, (c) 144, (d) 47, (o) 180 mollis, (o) 181, (d) 687 Porus opticus, 664 Posterior commissure, 207 Posterior — elastic layer of cornea, 658 ligament of knee, 636 medullary vellum, 214 pyramid, 184, 186 triangle of the neck, 63 vesicular column, 383 Poupart's ligament, 411, 559 Pouch, laryngeal, 155 of the auricula, 316, 319 Prepuce, 583 Princeps cervicalis artery, 368 pollicis artery, 280 of the foot, 624 Processus cochleariformis, 673 vermiformis, 212, 216 Profunda artery, inferior, 254 of the neck, (o) 78, (d) 368 of the thigh, 565, 578 superior, (o) 254, (d) 258 Promontory, 672 Pronator quadratus miiscle, 271 radii teres muscle, 264 Prostate gland, 571 connections, 507 structure, 521 Prostatic part of the urethra, 526 sinuses, 527 Psoas magnus muscle, 492, 580 Psoas parvus muscle, 493 Pterygoid arteries, 95 nerve, external, 95 internal, 95, 145 plexus of veins, 94 Pterygoideus externus muscle, 89 internus muscle, 90 Pterygo-maxillary ligament, 124 region, 87 palatine artery, 142 Pubic region of the abdomen, 431 symphisis, 546 Pudendal inferior nerve, (o) 589, (d) 394 Pudic arteries, external, 554, 565 artery, internal, (d) 390, (c) 398, 408, (o) 516 nerve, internal, (o) 408, (d) 390, 398 Pulmonary artery, (d) 318, 325, 335 nerves, 331 veins, 319, 329, 336 Puncta lachrymalia, 43, 60 Pupil, muscles of, 661 Pylorus, 453 Pyloric arteries, 447 Pyramid, anterior, 183, 185 decussation of, 186 of the cerebellum, 213 of the thyroid body, 120 of tlie tympanum, 672 posterior, 184, 186 Pyramidal fibres of the medulla, 185 masses of kidney, 474 Pyramidalis abdominis muscle, 416 nasi muscle, 34 INDEX 711 Pyramids of Malpighi, 474 Pyriformis muscle, 542, 587 QUADRATUS femoris muscle, 590 lumborum muscle, 494 RADIAL artery, 265, (d) 280, 289 nerve, 262, 270 veins, 266 cutaneous, 261 Radialis indicis artery, 272 Radio-carpal articulation, 296 Radio-ulnar articulations, 294, 297 Ranine artery, 101 vein, 101 RapliS of tlie corpus callosum, 200 of the medulla, 186 of the perinseum, 386 Receptaculum chyli, 495 Recto-vesical fascia, 5,02 pouch, 504 Rectus abdominis muscle, 415 capitis anticus major, 164 minor, 165 posticus major, 369 minor, 369 lateralis, 115 femoris, 570, 587 Rectus oculi externus, 57 inferior, 57 internus, 57 superior, 53 Rectum, connections of, in the female, 510 connections of, in the male, 504 structure, 532 Recurrent interosseous artery, 288 radial, 266 tibial, 631 ulnar, anterior, 268 posterior, 268 Recurrent nerve of pneumogastric, (o) 114, 331, (d) 158 nerve of the tibial, 631 Renal artery, (d) 476, (o) 489 plexus, 451 vein, (o) 476, (c) 492 Restiform body, 184, 186 Rete testis, 482 Retina, 663 structure, 664 Retrahens aurem, 18 Rhomboideus major muscle, 358 minor, 358 Rima of the glottis, 155 Ring, abdominal, external, 410 internal, 417, 421 Risorius Santorini muscle, 39 Rods of retina, 665 Root of the lung, 309, 310 Roots of the nerves, 307, 383 Rotatores dorsi, 371 Round ligament of the hip joint, 602 of the liver, 468 of the uterus, 418, 512, 539 SACCULE of the ear, 686 Sacculus laryngis, 155 vestibuli, 685 Sacral artery, lateral, 515 middle, 489, 517 ganglia, 519 nerves, anterior branches, 518 posterior branches, 372, 581, 584 plexus, 518 Sacro-coccygeal articulation, 544 iliac, 544 vertebral, 544 lumbalis muscle, 362 sciatic ligament, large, 545, 592 small, 545, 592 Salpingo-pharyngeus muscle, 126 Salvatella vein, 361 Saphenous vein, external, 606, 626 internal, 555, 573, 606, (o) 626 opening, 559 nerve, external, 606, (d) 627 internal, (o) 573, (d) 557, 573, 627 Sartorius muscle, 566 Scala tympani, 684 vestibuli, 684 Scalenus anticus muscle, 75 medius, 75 posticus, 75 Scapular artery, posterior, 78, 248, 359 ligaments, 247 muscles, 240, 244 Scapulo-clavicular articulation, 246 humeral, 290 Scarpa's triangle, 563 Schneiderian membrane, 135 Sciatic artery, (o) 516, (d) 588 nerve, large, 519, 589, 599 small, 519, 582, 588, 599 Sclerotic coat of the eye, 655 structure, 656 Scrotum, 408 Second nerve, (o) 179, (c) 57, (d) 664 Secondary membrane of the tympanum, 672, 673 Segments of the cord, 382 Semicircular canals, 680 Semilunar cartilages, 638 ganglia, 451 valves of aorta, 321 of pulmonary artery, 318 Semi-bulbs of vagina, 527 Semi -membranes us muscle, 598, 636 Seminal ducts, 523 Seminiferal tubes, 481 Semi-spinalis colli muscle, 370 dorsi muscle, 370 Semi-tendinosus muscle, 597 712 INDEX Septum auricularum, 322 cochleae, 682 crurale, 428, 561 intermuscular, of the arm, 258 of the thigh, 572 lucidum, 202 nasi, 134 pectiniforme, 530 scroti, 408 of the tongue, 147 ventriculorum, 324 Serratus magnus muscle, 236 posticus inferior, 360 superior, 360 Seventh nerve, (o) 180, (c) 142, (d) 47 Sheath of the fingers, 273 of the rectus, 415 of the toes, 616 Shoulder joint, 290 Sigmoid artery, 442 flexure of the colon, 434 valves, 318, 321 Sinus, basilar, 29 of the bulb, 527 cavernous, 28 circular, of Ridley, 29 coronary, 314 lateral, 28 longitudinal, inferior, 27 superior, 25 occipital, 27 petrosal, inferior, 29 superior, 29 pocularis, 526 prostaticus, 527 straight of the skull, 27 torcular, 27 transverse, 29 of Valsalva, 321 Sixth nerve, (o) 180, (c) 32, (d) 57 Small intestine, 429, 456 omentum, 438 Socia parotidis, 41 Soft commissure, 206 Soft palate, 128 muscles of, 128 Solar plexus, 451 Sole of the foot, dissection of, 614 Soleus muscle, 608 Solitary glands, 459, 464 Spermatic artery, (o) 489, (d) 484 cord, 418 fascia, 423 plexus, 443 veins (o) 484, (c) 492 Spheno-palatine artery, 142 ganglion, 139 nerves, 104 Sphincter ani externus, 389 internus, 389 of the pupil, 661 vaginae, 402 vesicae, 525 Spigelian lobe, 467 Spinal accessory nerve, (o) 181, (d) 114 nucleus, 187 arteries, 174, 379 cord, 380 membranes of, 374 structure, 382 nerves, 377 filaments of origin, 383 roots of, 377 veins, 385 Spinalis dorsi muscle, 362 Spiral tube of the cochlea, 682 Splanchnic nerve, large, 342, (d) 452 small, 342, (d) 452 smallest, 342, (d) 452 Spleen, 465 connections, 435 structure, 465 Splenic artery, 447, 466 omentum, 447 plexus of nerves, 451 vein, 448 Splenius capitis muscle, 361 colli, 361 Spongy bones, 134 part of the urethra, 527 Stapedius muscle, 676 Stapes bone, 675 Stellate ligament, 344 Stenson's duct, 41 Sterno-clavicular articulation, 170 cleido-mastoid muscle, 71 hyoid muscle, 73 thyroid, 73 Stomach, form and divisions, 453 connections of, 431 structure of, 453 Straight sinus, 27 Striate body, 203, 211 Stylo-hyoid ligament, 106 muscle, 83 nerve, 48 glossus muscle, 99, 148 mastoid artery, 94 maxillary ligament, 91 pharyngeus muscle, 106 Subanconeus muscle, 259 Subarachnoid space, 376 of the cord, 376 Subclavian artery, left, 118, (o) 328 right, 75 vein, 79 Subclavius muscle, 232 Subcrureus, 572 Subcutaneous malar nerve, 60, 104 Sublingual artery, 101 gland, 103 Submaxillary ganglion, 101 gland, 97 region, 97 Submental artery, 86 Suboccipital nerve, anterior branch, 115 posterior branch, 367 Subpeduncular lobe, 214 INDEX 713 Subperitoneal fat, 417, 561 Subpubic ligament, 547 Subscapular artery, 235 nerves, 236 Subscapularis muscle, 241 Substantia gelatinosa, 383 perforata antica, 192 Sulci of brain, 193, 213 Sulcus, longitudinal, of the liver, 467 spiralis, 683 transverse, 467 Superficial fascia of tlie abdomen, 405 of the perinseum, 392 of the thigh, 553, 554 Superficialis cervicalis artery, 359 volse artery, 266 Supinator radii brevis, 288 longus, 284 Supra-orbital artery, 21, 56 nerve, 22, 52 renal capsule, 478 plexus, 451 scapular artery, 78, 247, 359 nerve, 80, 248, 359 spinal artery, 248 spinatus muscle, 247 trochlear nerve, 23, 52 Suspensory ligament of the lens, 667 of the liver, 439 of the penis, 408 Sympathetic nerve in the abdomen, 443, 452 in the head, 33 in the loins, 497 in the neck, 115 in the pelvis, 519 in the thorax, 341 Symphysis pubis, 446 Synovial gland of Havers, 603 TAENIA hippocampi, 204 semicircularis, 204 Tarsal artery, 631 articulation, 647 cartilages, 44 Tarso-metatarsal articulations, 649 Taste buds, 147 Teeth, 132 Tegmentum, 191 Temporal aponeurosis, 19 artery, 86 deep, 94 middle, 87 superficial, 21 fascia, 19 muscle, 20, 88 nerves, deep, 95 superficial, 23, 48 vein, 21, 88 Temporo-fascial nerve, 48 malar nerve, 60 maxillary articulation, 90 sphenoidal lobe, 194 Tendo Achillis, 609 palpebrarum, 40 Tendon of triceps extensor, 566 Tensor palati muscle, 129 tarsi, 59 tympani, 676 vaginjB femoris, 570 Tentorium cerebelli, 27 Teres major muscle, 245 minor, 245 Testes, 479 Thalamus opticus, 207, 211 Thebesian foramina, 316 valve, 317 Thigh, dissection of, back, 592, 597 front, 552 Third nerve, (o) 180, (d) 54, 57, (c) 30 ventricle, 206 Thoracic duct, 118, 339, 494 ganglia, 339 Thoracic-acromial artery, 234 alar, 234 humeral, 234 long, 234 superior, 234 Thorax, boundaries of, 305 parietes of, 342, 237 Thymus body, 308 Thyro-arytsenoid articulation, 162 ligaments, 156 arytsenoideus muscle, 153 epiglottidean ligament, 162 hyoid membrane, 161 muscle, 73 Thyroid artery, inferior, 78, 121 superior, 85, 121 axis of artery, 78 body, 120 cartilage, 159 plexus of veins, 121 vein, inferior, 78, 121 middle, 82 superior, 85 Tibial artery, anterior, 630 posterior, 612 nerve, anterior. 683, (d) 627 posterior, 613 veins, anterior, 632 posterior, 613 Tibialis anticus muscle, 628 posticus, 611, 625 Tibio-tarsal articulation, 643 Tongue, 146 muscles of, 148 nerves of, 151 vessels of, 101 Tonsil, 131 Tonsilitic artery, 86 Torcular Herophili, 27 Trachea, connections of, 121, 333 structure of, 162 Trachelo-mastoid muscle, 363 Tractus intermedio-lateralis, 383 Tragus, 46 lU INDEX. Tragus — muscle, 46 Transverse colon, 434 fissure of the cerebrum, 204 of the liver, 468 ligament of the acetabulum, 602 of the atlas, 169 of the fingers, 273 of the knee, 639 of the metacarpus, 280 of the metatarsus, 624 of the toes, 615 perinaeal artery, 393 sinus, 29 tarsal articulation, 647 Transversalis abdominis muscle, 413 cervicalis artery, (o) 78, (d) 359 colli muscle, 363 faciei artery, (o) 87, (d) 41 fascia, 417, 428 Transversus auriculae muscle, 47 linguae, 150 pedis, 621 perinsei, 395, 403 deep, 397, 403 Trapezius muscle, 354 Trapezoid ligament, 246 Triangle of the neck, anterior, 69 posterior, 69 Triangular cartilage of the nose, 134 fibro-cartilage of wrist, 297 ligament of groin, 411 of the urethra, 396 space of the thigh, 562 surface of the bladder, 525 Triangularis sterni muscle, 238 Triceps extensor cruris, 570 cubiti, 258 Tricuspid valve, 318 Trigeminal nerve, (o) 180, (c) 31 Trigonum vesicae, 525 Trochlea, 53 Trochlear nerve, infra, 54 supra, 23, 52 Tube of the cochlea, 681 Tuber cinereum, 206 Tubercle of Rolando, 187 Tubules of the stomach, 454 of small intestine, 459 of large intestine, 463 Tubuli seminiferi, 481 uriniferi, 474 Tunica albuginea testis, 481 Ruyschiana, 660 vaginalis, 480 oculi, 655 vasculosa testis, 481 Turbinate bones, 134 Twelfth intercostal nerve, 416, 498, 581 Tympanic artery, 93 Tympanum, 674 arteries of, 674 lining membrane, 677 nerves of, 677 ULNAR artery, 267, 273 nerve, (o) 236, (c) 255, (d) 269, 274 veins, 268 cutaneous anterior, 261 posterior, 261 Umbilical hernia, 426 region of the abdomen, 431 vein, 469 Umbilicus, 404 Ureter, 477, 510, 526 Urethra, female, 541 connections, 512 orifice of, 535 structure, 542 male, interior, 526 connections, 507, 526 structure, 527 Uterine arteries, 511', 539 plexus of nerves, 520 veins and sinuses, 517 Uterus, 537 interior of, 538 ligaments of, 510 connections of, 511 structure of, 538 Utricle of the ear, 685 Uvea iridis, 661 Uvula cerebelli, 212 palati, 128 vesicae, 574 VAGINA, connections, 512, 535 structure and form, 536 Vaginal arteries, 516, 537 plexus, 520 veins, 517 Vagus nerve, 112, 181, 330, 452 nucleus, 187 Vallecula, 212 Valve, Eustachian, 317 of caecum, 462 mitral, 320 semilunar, 318, 321 of Thebesius, 317 tricuspid, 318 of Vieussens, 215 Valvulae conniventes, 457 Vas deferens, 418, 483, 523 aberrans, 483 Vasa aberrantia, 250 brevia, 447 efferentia testis, 482 rete testis, 482 vorticosa, 660 Vascular coat of eye, 658 Vastus extern us muscle, 571 internus muscle, 571 Vein, alveolar, 142 angular, 21 ascending cervical, 78 lumbar, 498 pharyngeal, 110 auditory, 687 INDEX 715 Vein- auricular, posterior, 21 axillary, 235 azygos, large, 338, 495 small, 338, 494 superior, left, 338 basilic, 249 brachial, 255 bracliio-ceplialic, left, 329 right, 328 bronchial, left, 336, 337 right, 336, 337 cardiac, anterior, 314 great, 314 small, 314 cava, inferior, 329, 444, 492 superior, 328 cephalic, 250 cerebellar, 177 cerebral, 177 choroid, 206 ciliary, anterior, 662 posterior, 663 circumflex iliac, 420, 491 coronary of the heart, 314 of the stomach, 448 of the corpus cavernosum, 531 striatum, 206 deep cervical, 77, 368 diaphragmatic, inferior, 492 dorsal, of the penis, 517 dorsi-spinal, 369 emissary, 21 emulgent, 476, 492 epigastric, deep, 420, 491 superficial, 407, 554 facial, 40, b6 femoral, 565, 568 frontal, 21 of Galen, 208 gastro-epiploi'c, left, 449 hemorrhoidal, 517, 533 hepatic, 471, 492 iliac, common, 491 external, 491 internal, 517 infraorbital, 40, 105 innominate, 328 intercostal, 338 posterior branch, 368, 385 superior, left, 338 right, 338 intraspinal, 385 interlobular, 471 intralobular, 471 jugular, anterior, 71 external, 42, 62 internal, left, 118 right, 82, 109 laryngeal, 158 lingual, 101 longitudinal, of the spine, anterior, 385 lumbar, 369, 498 Vein — mammary, internal, 238, 329 median, of the arm, 249, 261 basilic, 249 cephalic, 249 maxillary, internal, 94, 329 anterior, internal, 40, 142 mesenteric, inferior, 443 superior, 441 occipital, 21, 80, 369 ophthalmic, 57 ovarian, 492 palpebral, inferior, 40 pancreatic, 448 perineal, superficial, 393 pharyngeal, 110 phrenic, inferior, 492 popliteal, 596 portal, 448, 471 posterior, spinal, plexus of, 385 profunda of the thigh, 579 pterygoid plexus, 94 pudic external, 555 internal, (o) 399, (c) 532 pulmonary, 319, 329 radial cutaneous, 261 ranine, 101 renal, 476, 492 sacral, lateral, 517 middle, 517 saphenous, external, 606, (o) 626 internal, 555, (o) 626 spermatic, 484, 492 spinal, 380 splenic, 448 subclavian, 79 sublobular, 471 supra-orbital, 21 renal, 479, 492 scapular, 78, 248, 359 temporal, 21, 87 superficial, 21 thyroid, inferior, 78, 121, 329 middle, 82 superior, 85 tibial anterior, 632 posterior, 613 transverse cervical, 78, 359 ulnar, 267 cutaneous, anterior, 261 posterior, 261 umbilical, 469 uterine, 517 vaginal, 517 vertebral, 77, 166 vesical, 517 of the vertebrae, 385 Velum interpositum, 205 pendulum palati, 128 Vena cava, inferior, 444, 492 superior, 328 port*, 449, (d) 471 : Ven.ie cavje hepaticse, 471 I Venous arch of the foot, 626 716 INDEX Venous arch — of the hand, 261 Ventricles of the brain, 200 fifth, 202 fourth, 217 lateral, 200 third, 206 of the heart, 313 left, 320 right, 317 structure of, 321 of the larynx, 156 Vermiform appendix, 433, 462 processes, 212, 216 Vertebral artery, (o) 77, (c) 165, (d) 174 plexus, 117, 166 vein, 77, (o) 166 Veru montanum, 526 Vessels of the brain, 174 of the dura mater, 29, 376 Vesica urinaria, 524 Vesical artery, inferior, 515 superior, 515 plexus of nerves, 520 veins, 517 Vesicula prostatica, 526 Vesicular column of cord, 383 Vesiculse seminales, connections, 507 structure, 522 Vestibule of the ear, 679 artery of, 687 nerve of, 687 of the vulva, 535 Vestigial fold of pericardium, 311 Vidian artery, 142 nerve, 141 Villi, intestinal, 458 Vitreous body, 666 fluid, 667 Vocal cords, 156 Vulva, 533 WHARTON'S duct, 98, 103 White commissure of the cord^ 382 Winslow's foramen, 437 Wrisberg's nerve, 236, 251, 256 Wrist-joint, 296 ELLOW spot of eyeball, 664, 666 ZONULE of Zinn, 667 Zygomaticus major muscle, 39 minor muscle, 39 THE END. (LATE LEA k BLANCHARD'S) OF MEDICAL AND SUEGICAL PUBLICATIONS. In asking the attention of the profession to the works advertised in the following pages, the publisher would state that no pains are spared to secure a continuance of the confidence earned for the publications of the house by their carefulselection and accuracy and finish of execution. The printed prices are those at which books can generally be supplied by booksellrrs throughout the United States, who can readily procure for their customers any works not kept in stock. Where access to bookstores is not convenient, books will be sent by mail post-paid on receipt of the price, and as the limit of mailable weight has been removed, no difficulty will be experienced in obtaining through the post-office any work in this catalogue. 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With its attendant periodicals, the "Medical News and Library" and the "Monthly Abstract OF Medical Science," it combines the advantages of the elaborate prepacation which can be given to a quarterly, and the prompt conveyance of intelligence by the monthly, while, the whole being under a single editorial supervision, the subscriber is secured against the duplication of matter inevitable under other circumstances. These efforts the publisher seeks to second by offering these periodicals at a price unprece- dentedlylow — a price which placesthem within the reachoferery practitioner, and gives the equivalent of three or four large octavo volumes for the comparati^vely trifling (For The "Obstetrical Journal," see p. 24.) 2 Henry C. Lea's Publications — (Am. Journ. Med. Sciences), cost of Six Dollars per annum. The three periodicals thus offered are universally known for their high professional standing in their several spheres. THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES, Edited BY I. MINIS HAYS, M.D., is published Quarterly, on the first of January, April, July, and October. Each num- ber contains nearly three hundred large octavo pages,appropriately illustrated wher- ever necessary. It has now been issued regularly for over fifty years, during the whole of which time it has been under the control of the presentseuior editor. Through- out this long period, it has maintained its position in the highest rank of medical peri- odicals both at home and abroad, and has received the cordial support of the entire profession in this country. Among its Collaborators will be found a large number of the most distinguished names of the profession in every section of the United States, rendering its original department a truly national exponent of American medicine.* Following this is the "'Rkview Department," containing extended and impartial reviews of important new works, together with numerous elaborate "Analytical and Bibliographical Notices" giving a complete survey of medical literature. This is followed by the "Quarterly Summary of Improvements and Discoveries in the Medical Sciences," classified and arranged under different heads, presenting a very complete digest of medical progress abroad as well as at home. Thus, during the year 1878, the "Journal" furnished to its subscribers 77 Original (Communications, 183 Reviews and Bibliographical Notices, and ^55 articles in the Quarterly Summaries, making a total of Four Hundred and Sixty-five arti(-les illustrated with 48 maps and wood engravings, emanating from the best professional minds in America and Europe. 'i'hat the efforts thus made to maintain the high reputation of the "Journal" are successful, is shown by the position accorded to it in both America and Europe as a leading organ of medical progress: — This 16 uuivevHally acknowledged as the leading Oar venerable contemporary has our best wishes, American Journal, and has been conducted by Dr. j and we can only express the hope that it may con- Hays alone until 1869, when his sou was associated tinue its work with as much vigor and excellence for wich him. We quite agree with the critic, that this the next fifty years as it has exhibited iu the past, journal is second to uoue in the language, and cheer- j — London Lancet, Nov. 24, 1877, fully accord to it the first place, for nowhere shall ! „. •, j , , • nr j- , ^ t., -it we find more able and more impartial criticism, and The Philadelphia Medical and Physical Journal nowhere such a repertory of able original articles, issued its first number in 1820, and, after a brilliant Indeed, now that the "B'riiish and Foreign Medico- career, was succeeded in 1827 by the American Chirurgical Review" has terminated its career, the : Journal of the Medical Sciences, a periodical of American Journal stands without a rival.— Zoredon world-wide reputation; the ablest and one of the Med. Times and Gazette, Nov. 24, 1877. oldest periodicals in the world— a journal which has „, , ,. , J , ., .. X Ti an unsullied record. — Gross's History of American The best medical jourual on the continent — Bos- ^^d Literature 1876 ton Med and Surg. Journal, h.-^v\\n,\%lQ. i m, • • ., j' , • ■. , ,. . , . . ,, , ,,,.,,,,. I Ihis IS the medical journal of our country to whicn It 18 universally acknowledged to be the leading ^1,^ American physician abroad will point witli tht American medical journal, and, in our opinion. greatest satisfaction, as reflecting the state of medical second to none in ttie language— fio*f on Med. and culture in his country. For a great many years it tiarg. Journal^ Oct. IS//. ^i'd.^ been the medium through which our ablest writ- The present number of the American Journal is an ers have made known their discoveries and observa- exceedingly good one, and gives every promise of tions — Address of L. P. Yandell, M.D., before Inter- maintaining the well earned reputation iif the review, national Med. Congress, Sept. 1876. And that it was specifically included in the award of a medal of merit to the Publisher in the Vienna Exhibition in 1873. 'l"he subscription price of the "American Journal of the Medical Sciences" has never been raised during its long career. It is still Five Dollars per annum ; and when paid for in advance, the subscriber receives in addition the "Medical News and Library," making in all about 1.500 large octavo pages per annum, free of postage. THE MEDICAL NEWS AND LIBRARY is a monthly periodical of Thirty-two large octavo pages, making 384 pages_ per annum. Its "Library DkpartmexXt" is devoted to publishing standard works on the various branches of medical science, paged separately, so that they can be detached for i)inding, when complete. In this manner subscribers have received, without ex- pense, such works as "Watson's Practice," "West on Children," "Malgaignk's Surgery," "Stokes on Fever," Gosselin's "Clinical Lectures on Surgery," and many other volumes of the highest reputation and usefulness. With July, 1878, was commenced the publication of "Lectures on Diseases of the Nervous System," by J. M. Charcot, Professor in the Faculty of Medicine of Paris, translated from the French by (jFiorge Sigerson, M.D., Lecturer on Biology, etc., Catholic Univ. of * Coramiinlcatious are invited from gentlemen in all parts of the country. Elaborate articles inserted by the Editor are paid for by the Publisher. Henry C. Lea's Publications— (^wi. Journ. Med. Sciences). 3 Ireland [see p. 17), which will be continued to completion during 1879. New sub- scribers, commencing with Junuary, 1879, can procure the previous portion by a remittance of 50 cents, if promptly made. The " Nkws Dkpartmknt" of the "Mkdical News and Library" presents the current information of the month, with Clinical Ijectures and Hospital Gleanings. A new and attractive feature of this will be found in an elaborate series of Original American Clinical Lectures, specially contributed to the News by gentlemen of the highest reputation in the profession throughout tho United States. During 1878 there have appeared Lectures by S. D. Gross, M.D., Prof, of Surgery, Jefferson Med. Coll., Philada. T. Gaillard Thomas, M.D., Prof. Obstetrics, &c.. Coll. Phys. and Surg., N. Y. William Pepper, M.D., Prof. Clin. Medicine, Univ. of Penna. Lewis A. Sayre.M.D., Prof. Orthopaedic Surg., Bellevue Hosp. Med. Coll., N.Y. Egberts Bartiiolow, M.D., Prof. Theory and Practice of Med., Med. Coll. of Ohio. T. G. Richardson, M.D., Prof. Genl. and Clin. Surg., Univ. of La., New Orleans. S. W. Gross, M.D., Surg, to Philada. Hospital. F. Peyre Porcher, M.D.,Prof. of Mat. Med. and Clin. Medicine, Med. CoU.of S. C. William Goodell, M.D., Prof. Clin. Gynaecology, Univ. of Penna. N. S. Davis, M.D., Prof. Prin. and Pra'c. of Med., Chicago Med. Coll. W. H. Van Buren, M.D., Prof. Surgery, Bellevue Hosp. Med. Coll., N.Y. To be followed by others of similar value from Austin Flint, M.D., Prof. Prin. and Prac. of Med., Bellevue Hosp. Med. Coll., N.Y. FoRDYCE Barker. M.D., Prof. Clin. Midwifery ,&c., Bellevue Hosp. Med. Coll., N.Y. L. A, DuHRiNG, M.D., Clin. Prof, of Diseases of the Skin, Univ. of Penna. Theophilus Parvin, M.D., Prof. Obstetrics, &c., Coll. Phys. and Surg., Indianapolis. J. P. White, M.D., Prof, of Obstetrics, &c., Univ. of Buffalo. John Ashhurst, Jr., M.D., Prof, of Clin. Surg., Univ. of Penna. D. Warren Brickell, M.D., Prof. Obstetrics, &c.. Charity Hosp. Med. Coll., N. 0. J. Lewis Smith, M.D., Clin. Lee. on Dis. of Chil., Bellevue Hosp. Med. Coll., N. Y. William F. Nqrris, M.D., Clin. Prof, of Diseases of the Eye, Univ. of Penna. P. S. Conner, M.D., Prof., of Anat. and Clin. Surgery, Med. Coll. of Ohio, Cin. S. Weir Mitchell, M.D., Phys. to the Infirmary for Nervous Diseases, Philada. J. M. DaCosta, M.D., Prof. Prin. and Prac. of Med., Jeff. Med. Coll., Philada. Thomas G. Morton, M.D., Surgeon to Penna. Hospital, Philada. F. J. Bumstead, M.D., late Prof, of Venereal Dis., Coll. Phys. and Surg., N.Y. J. H. Hutchinson, M.D., Physician to Penna. Hospital. Christopher Johnson, M.D., Prof, of Surgery, Univ. of Md., Baltimore. William Thomson, M.D., Lecturer on Ophthalmology, Jeff. Med. Coll., Philada. With contributors such as these, representing every portion of the United States, the publisher feels safe in promising to the subscriber a series of practical lectures unsurpassed in variety, interest, and value. As stated above, the subscription price of the " Medical News and Library" is One Dollar per annum in advance; and it is furnished without charge to all advance- paying subscribers to the "American Journal of the Medical Sciences." III. THE MONTHLY ABSTRACT OF MEDICAL SCIENCE is issued on the first of every month, each number containing forty-eight large octavo pages, thus furnishing in the course of the year about six hundred pages. The aim of the •' Abstract" is to present — without duplicating the matter in the "Journal" and " News" — a careful condensation of all that is new and important in the medical journalism of the world, and all the prominent professional periodicals of both hemi- spheres are at the disposal of the Editors. 'I'o show the manner in which this plan has been carried out it is sufficient to state that during the year 1878 it contained — 30 Articles on Anfitoniy and I'hysiologij. /><» ** •' Mati'vla Medica and Therapeutics, '^30 « « AK'diiine. 15 L '* " Surf/eri/. 79. <• «* 3li(iitu/'rrfj and Gf/na^coloyif, I'J '* " JSli'dical fTtiri.sprudeuce uiid Toxicology — making in all .558 articles in a single year. The subscription to the " Monthly Abstract," free of postage, is Two Dollars AND^ Half a year, in advance. As stated above, however, it will be supplied in conjunction with the "American Journal of the Medical Sciences" and the "Medical News and Library," making in all about Twenty-one Hundred pages per annum, the whole /ree of postage, for Six Dollars a year, in advance. In this effort to bring so large an amount of practical information within the reach of every member of the profession, the publisher confiJently anticipates the friendly 4 Henry C. Lea's Publications — {Dictionaries). aid of all who are interested in the dissemination of sound medical literature. He trusts, especially, that the subscribers to the "Amkrican Medical Journal" will call the attention of their acquaintances to the advantages thus ottered, and that he will be sustained in the endeavor to permanently establish medical periodical literature on a footinir of cheapness never heretofore attempted. PREMIUM rOR OBTAINING NEW SUBSCEIBERS TO THE "JOURNAL." Any (rentleman who will remit the amount for two subscriptions for 1879, one of which must be for a neiu t^uhscnher, will receive as a premium, free by mail, a copy of " Holden's Landmarks, Medical and Suhgical" (for advertisement of which see p. 6), or of Fothehgill's " Antagonism of Medicines" (see p. If.), or of " Browne on THE Use of the Ophthalmoscope" (seep. 20), or of " Ffjnt's Essays on Conservative Medicine" (see p. I.t), or of "Sturges's Clinical Medicine" (see p. 14), or of the new edition of "Swayne's Obstetric Aphorisms" (see p. 21), or of "Tanner's Clinical Manual" (see p. 5), or of "Chambers's Restorative Medicine" (see p. 18), or of "West on Nervous Disorders of Children ' (see p. 20;. *^* Gentlemen desiring to avail themselves of the advantages thus offered will do well to forward their subscriptions at an early day, in order to insure the receipt of complete sets for the year 1879. t^ The safest mode of remittance is by bank check or postal money order, drawn to the order of the undersigned. Where these are not accessible, remittances for the "Journal" may be made at the risk of the publisher, by forwarding in registered letters. Address, HENRY C. LEA, Nos. 706 and 708 Sansom St., Philadelphia, Pa. jyUNOLISON {ROBLEY), M.D., '^'^ Late Professor of Institutes of Medicine in Jefferson Medical College, Philadelphia. MEDICAL LEXICON; A Dictionary op Medical Science: Cor- tfiining a concise eKpltination of the various Subjects and Terms of Anatomy, Physiology, Pathology, Hygiene, Therapeutics. Pharmacology, Pharmacy, Surgery, Obstetrics, Medicnl Jurisprudence, and Dentistry. Notices of Climate and of Mineral Waters ; Formulae fur Officinal, Empirical, and Dietetic Preparations; with the Accentuation and Etymology of the Terms, and the French and other Synonymes ; so as to constitute a French as well as English Medical Lexicon. A New Edition. Thoroughly Revised, and very greatly Mod- ified and Augmented. By Richard J. I>unglison, M.D. In one very large and hand- some royaloctavo volume of over 1100 pages. Cloth, $6 50; leather, raised bands, $7 50. (J?/5< Issued.) The object of the author from the outset has not been to make the work a mere lexicon or dictionary of terms, but to afford, under each, a condensed view of its various medical relations, and thus to render the work an epitome of the existing condition of medical science. Starting with this view, the immense demand which has existed forthe work has enabled him, in repeated revisions, to augment its completeness and usefulness, until at length it has attained the position of a recognised and standard authority wherever the language is spoken. Special pains have been taken in the preparation of the present edition to maintain this en • viable reputation. During the ten years which have elapsed since the last revision, the additions to the nomenclature of the medical sciences have been greater than perhaps in any similar period of the pait, and up to the time of his death the author labored assiduously to incorporate every- thing requiring the attention of the student or practi^Joner. Since then, the editor has been equally industrious, so that the additions to the vocabulary are more numerous than in any pre- vious revision. Especial attention has been bestowed on the accentuation, which will be found marked on every word. The typographical arrangement has been much improved, rendering reference much more easy, and evary care has been taken with the mechanical execution. The work has been printed on new type, small but exceedingly clear, with an enlarged page, so that the additions have been incorporated with an increase of but little over a hundred pages, and the volume now contains the matter of at least four ordinary octavos. ^^ience so extensive, and with such collaterals as medi- ;ine, it is as much a necessity also to the practising ohynician. To meet the wants of students and most physiitians, the dictionary must be condensed while A book well known to our readers, and of which every American ought to he proud. When the learned author of the work paused away, probably all of us feared lest the book should not maintain its place in the advancing science whoRo terms it defines. For- tunately, Dr. llichard J. Dun|ili3on, having assisted liis father in the revision of several editions of the work, and having been, therefore, trained in the methods and imbued with the spirit of the book, has been able to edit it, not in the patchwork manner so dear to the heart of book editors, so repulsive to the taste of intel- ligent book readers, but to edit it as a work of the kind should be edited — to carry it on steadily, without jar or interruption, along the grooves of thought it has travelled during its lifetime. To show the magnitude of the task which Dr. Dunglison has assumed and car- ried through, it is only nec<;ssary to state that more than six thousand new subjects have been added in the present edition.— P^iZa. Med. Times, Jan. 3, 1874. About the first book purchased by the medical stu- dent is the Medical Dictionary. The lexicon explana- tory of technical term?" is simply a iitie qua non. In a ' comprehensive, and practical while perspicacious. Jt 'vas becaupe Dunglison's met these indications that it became at once the dictionary of general use wherever medicine was studied in the Knglish language. In no formerrevision have the alterations and additions been ■(o great. More than six thousand new subjects and terms liave been added. The chief terms have been set in black letter, while the derivatives follow in small caps; an arrangement which greatly facilitates reference. We may safely confirm the hope ventured by the editor " that the work, which possesses for him a filial as well as an individual interest, will be found worthy a con- tinuance of the position so long accorded to it as a standard authoritv."— Cincinnrtrt Clinic, Jan. 10, 1874. It has the rare merit that it certainly has no rival In the English language for accHracy and extent of refereuces. — London Medical Oatette. Henry C. Lea's Publications — {Manuals), A CENTURY OF AMERICAN MEDICINE, 1776-1876. By Doctors E. H. -^ Clarke, H. J. Bigelow, S. D. Gross, T. G. Thomas, and J. S. Billings. In one very hand- some 12mo. volume of about 350 pages : cloth, $2 25. {Just Ready.) This work appeared in the pages of the American Journal of the Medical Sciencesduring the year 1876. As a detailed account of the development of medical science in America, by gentle- men of the highest authority in their respective departments, the profession will no doubt wel- come it in a form adapted for preservation and reference. E OBLYN {RICHARD D.), M.D. A DICTIONARY OF THE TERMS USED IN MEDICINE AND THE COLLATERAL SCIENCES. Revised, with numerous additions, by Isaac Hays, M. D., Editor of the " American Journal of the Medical Sciences." In or^ large royal 12mo. volume of over 600 double-columned pages; cloth, $1 50 ; leather, $z 00 It is the best book of defluitions we have, aud ought always to be upou the student's i&h\Q.— Southern Med. and Surg. Journal. T>OD WELL [G. F), F.R.A.S.. ^r. A DICTIONARY OF SCIENCE: Comprising Astronomy, Chem- istry, Dynamics, Electricity, Heat, Hydrodynamics, Hydrostatics, Light, Magnetism, Mechanics, Meteorology, Pneumatics, Sound, and Statics. Preceded by an Essay on the History of the Physical Sciences. In one handsome octavo volume of 694 pages, and many illustrations : cloth, $5. l^EILL {JOHN), M.D., and J^MITH {FRANCIS G.), M.D., "^ Prof, of the Institutesvf Medicine in the Univ. of Penna. AN ANALYTICAL COMPENDIUM OF THE VARIOUS BRANCHES OF MEDICAL SCIENCE; for the Use and Examination of Students. A new edition, revised and improved. In one very large and handsomely printed royal 12mo . volume, of about one thousand pages, with 374 wood-cuts, cloth, $4 ; strongly bound in leather, with raised bands, $4 75. H ARTSHORNE {HENRY), M. D., Professor of Hygiene in the University of Pennsylvania. A CONSPECTUS OF THE MEDICAL SCIENCES; containing Handbooks on Anatomy, Physiology, Chemistry, Materia Medica, Practical Medicine, Surgery, and Obstetrics. Second Edition, thoroughly revised and improved. In one large royal 12mo. volume of more than 1000 closely printed pages, with 477 illustrations on wood. Cloth, $4 25 ; leather, $5 00. {Lately Issued.) dents, btit to many others whomay desire torefresh their memories with the smallest possible expendi- ture of time. — N. Y. Med. Journal, Sept. 1874. The student will find this the most convenient and useful book of the kind on which he can lay his hand. — Pacific Med. and Surg. Journ., Aug. 1S74. This is the best book of its kind that we have ever examined. It is an honest, accurate, aud concise compend of medical sciences, as fairly as possible representing their present condition. The changes and the additions have been so judicious and tho- rough as to render it, so far as it goes, entirely trust- worthy. If students mast have a conspectus, they will be wise to procure that of Dr. Hartshorne. — Detroit Rev. of Med and Pharm., Aug. 1874. We can say with the strictest truth that it is the best work of the kind with which wc artacqnainted. It embodies ina condensed form ii.il recent coutiibu- tions to practical medicine, ana is therefore useful to every busy practitioner throughout our country, besides being admirably adapted to the use of stu- dents of medicine. The book is faithfully and ably executed. — Charleston Med. Journ., April, 1875. The work is intended as an aid to the medical student, and as such appears to admirably fulfil its object by itsexcellent arrangement, the full compi- lationof facts, the perspicuity and terseness of lan- guage, and the clear and instructive illustrations in some parts of the work — American Journ. of Pharmacy, Philadelphia, July, 1874. The volume will be found useful, not only to stu- TUDLOW {J.L.), M.D. A MANUAL OF EXAMINATIONS upon Anatomy, Physiology, Surgery, Practice of Medicine, Obstetrics, Materia Medica, Chemistry, Pharmacy, and Therapeutics. To which is added a Medical Formulary. Third edition, thoroughly revised and greatly extended and enlarged. With 370 illustrations. In one handsome royal 12mo. volume of 816 large pages, cloth, $3 25 ; leather, $3 75. ' The arrangement of this volume in the form of question and answer renders it especially suit- able for the office examination of students, and for those preparing for graduation. /TANNER {THOMAS HAWKES), M.D., §-c. ^ A MANUAL OF CLINICAL MEDICINE AND PHYSICAL DIAG- NOSIS. Third American from the Second London Edition. Revised and Enlarged by Tilbury Fox, M. D., Physician to the Skin Department in University College Hospital, Ac. In one neat volumesmall 12mo., of about 375 pages, cloth, $150. *^* On page 4, it will be seen that this work is offered as a premium for procuring neW subscribers to the "Amekican Journal op the Medical Sciences." Henry C. Lea's Publications — (Anatomy). QRAY {HENRY), F.R.S., Lecturer on Anatomy at St. George's Hospital, London. ANATOMY, DESCRIPTIVE AND SURGICAL. The Drawings by H. V. Carter, M.D., and Dr. Westmacott. The Dissecbionsjointly by the Author and Dr. Carter. With an Introduction on General Anatomy and Development by T. lIoLMBS, M.A., Surgeon to St. George's Hospital. A new American, from the eighth enlargec and improved London edition. To which is added *' Landmarks, Medical, and Surgical," by Luther Holden, F.R C.S., author of " Human Osteology," '* A Manual of Dissections," etc. In one magnificent imperial octavo volume of 983 pages, with 522 large and elaborate engravings on wood. Cloth, $6; leather, raised bands, $7. {^Just Ready.) The author has endeavored inthisworkto cover a more extendedrange of subjects than iscue- tomary in tWe ordinary text-books, by giving not only the details necessary for the student, but also the application of those details in the practice of medicine and surgery, thusrendering it both a guide for the learner, and an admirable work of reference for the active practitioner. The en- gravings form a special feature in the work, many of them being the size of nature, nearly all original, and having the names of the various parts printed on the body of the cut, in place of figures of reference, with descriptions at the foot. They thus form a complete and splendid series, which will greatly assist the student in obtaining a clear idea of Anatomy, and will also serve to refresh the memory of those who m^ay find in the exigencies of practicethenecessity of recalling the details of the dissecting room ; while combining, as it does, a complete Atlas of Anatomy, with a thorough treatise on systematic, descriptive, and applied Anatomy, the work will be found of essential use to all physicians who receive students in their offices, relieving both preceptor and pupil of much labor in laying the groundwork of a thorough medical education. Since the appearance of the last American Edition, the work has received three revisions at the hands of its accomplished editor, Mr. Holmes, who has sedulously introduced whatever has seemed requisite to maintain its reputation as a complete and authority iive standard text-book and work of reference. Still further to increase its usefulness, there has been appended to it the recent work by the distinguished anatomist, Mr. Luther Holden — "Landmarks, Medical and Surgical" — which gives in a clear, condensed, and systematic way, all the information by which the prac- titioner can determine from the external surfiice of the body the position of internal parts. Thus complete, the work, it is believed, will furnish all the assistance that can be rendered by type and illustration in anatomical study. No pains have been spared in the typographical execution of the volume, which will be found in all respects superior to former issues. Notwithstanding the increase of size, amounting to over 100 pages and 57 illustrations, it will be kept, as heretofore, at a price rendering it one of the cheapest works ever offered to the American profession. The recent work of Mr. Holden, which was no- ticed hy us ou p. 53 of this volume, has been added as an appendix, so that, altogether, this is the mott practical and complete anatomical treatise available to American students and phynicians. The former finds in it the necessary guide in making dissec- tions ; a very comprehensive chapter on mittute matom-v; and about all that can he taught him on to consult his books oa anatomy. The work is simply indispensable, especially this present Amer- ican edition.-— Fa. Med. Monthly, Sept. 187?. The addition of the receut work of Mr. Holden, as an appendix, renders this the most practical and complete treatise available to American students, who find in it a comprehensive chapter on minute jreneraiVnd special anatomy; while the latter, in anatomy, about all that can be taught on general *t8 treatment of each region from a surgieal point of an^i special anatomy, while its treatment of each view, and in the valuable edition of Blr Holden will find all that will be essential to him in his practice —i\^ew Remedies, Aug. 1878. This work is as near perfection as one could pos- sibly or reasonably expect any book intended as a text-book or a genera) reference book on anatomy to be. The American publisher deserves the thanks of the profession for appending the recent work of Mr. Holden, ^* Landmarks, Medical and Surgical,''^ which has already been commended as a separate book. The latter work— treating of topographical anatomy— Jias become an essential to the library of every intelligent practitioner. We know of no book tliat can take its place, written as it is by a most distinguished anatomist. It would be simply a waste of words to say anything further in praise of Gray's Anatomy, the text-book in almost every medical college in this country, and the daily refer- ence book of every practitioner who has occasion egion, from a surgical point of view, in the valu- able section by Mr. Holden, is all that will be essen- tial to them in practice.— 0/ito Mtdical Recorder, Aug. 1878. It is diflicult to speak in moderate terms of this new edition of "Gray." It seems to be as nearly perfect as it is possible to make a book devoted to any branch of medical science. The labors of the eminent men who have successively revised the eight editions through which it has passed, would seem to leave nothing for future editors to do. The addition of Holden's " Landmarks" will make it as indi8pen.sable to tl;e practitioner of medicine and surgery as it has been heretofore to th» student. As regards completeness, ease of reference, utility, beauty, and cheapness, it has no rival. No stu- dent should enter a medical school without it ; no physician can afford to have it absent from his library.- S^ Louis Clin. Record, Sept. 1878. Also for sai/e separate — TTOLDEN {LUTHER), F.R.C.S., J- J- Surgeon to St. Bartholomew' s and the Foundling Hospitals. LANDMARKS, MEDICAL AND SURGICAL. From the 2d London Ed. In one handsome volume, royal 12mo., of 128 pages : cloth, 88 cents. {Now Ready.) TJEATH {CHRISTOPHER), F.R.G.S., -■3[ Teacher of Operative Surgery in University College, London. PRACTICAL ANATOMY: A Manual of Dissections. From the Second revised and improved London edition. Edited, with additions, by W. W. Keen, M. D., Lecturer on Pathological Anatomy in the Jefferson Medical College, Philadelphia. In one handsome royal 12mo. volume of 578 pages, with 247 illustrations. Cloth, $3 60 ; leather, $4 00. Henry C. Lea's Publications — {Anatomy). A LLEN {HARRISON), M.D. -^J- Pro/esior of Thy aio logy in the Univ. of Pa. A SYSTEM OF HUMAN ANATOMY: INCLUDING ITS MEDICAL and Surgical Relations. For the Use of Practitioners and Students of Medicine. With an Introductory Chapter on Histology. By E. 0. Shakespeahe, M D., Ophthalmologist to the Phila. IIosp. In one large and handsome quarto volume, with several hundred original illustrations on lithographic plates, and numerous wood-cuts in the text. (Preparing.) In this elaborate work, which has been in active preparation for several years, the author has sought to give, not only the details of descriptive anatomy in a clear and condensed form, but also the practical applications of the science to medicine and surgery. The work thus has claims upon the attention of the general practitioner, as well as of the student, enabling him not only to re- fresh his recollections of the dissecting room, but also to recognize the significance of all varia- tions from normal conditions. The marked utility of the object thus sought by the author is self-evident, and his long experience and assiduous devotion to its thorough development are a sufficient guarantee of the manner in which his aims have been carried out. No pains have been sp.ared with the illustrations. Those of normal anatomy are from original dissecti^Jns, drawn on stone by Mr. Hermann Faber, with the name of every part clearly engraved upon the figure, after the manner of "Holden" and "Gray," and in every typographical detail it will be the effort of the publisher to render the volume worthy of the very distinguished position which is anticipated for it. -UiLLIS [GEORGE FINER), -*-^ Emeritus PrifKSHor of Anatomy in University College, London. DEMONSTRATIONS OF ANATOMY; Being a Guide to the Know- ledge of the Human Body by Dissection. By George Viner Ellis, Emeritus Professor of Anatomy in University College, London. From the Eighth and Revised London Edition. In one very handsome octavo volume of oyer 700 pages, with 256 illustrations. Cloth, S4. 25 ; leather, $5.25. {Jvst Ready.) This work has long been known in England as the leading authority on practical anatomy, and the favorite guide in the dissecting-room, as is attested by the numerous editions through which it has passed. In the last revision, which has just appeared in London, the accomplished author has sought to bring it on a level with the most recent advances of science by making the necessary changes in his account of the microscopic structure of the different organs, as devel- oped by the latest researches in textural anatomy. Ellife's Demoastrations is the favorite text-book ] its leadership over the English manuals upon dis- of the English Btudent of anatomy. In passing thi-oufi;h eight editions it has been bO revised and adapted to the needs of the student ibat it would seem that it had almost reached perfection in Ibirs special line. The descriptions are clear and the , - . , . . •, , methods of pursuing anatomical inve.'.tigations are | tain y saying a very great deal. As a text-book to secting. — Phila, Med. Timts, May 24, 1879. As a dissector, or a work to have in hand and studied while one is engaged in dissecting, we re gard it as tlie very best work extant, which is cer- be studied in the dissecling-room, it is superior to any of the works upon anatomy.— Ci7iet'?ina Va. Me'1. Monthly, June, 1879. w ILSON [ERASMUS), F.R.S. A SYSTEM OF HUMAN ANATOMY, General and SpeciaL Edited by W. H. GoBRECtiT, M.D , Professor of General and Surgical Anatomy in the Medical Col- lege of Ohio. Illustrated with three hundred and ninety-seven engravings on wood. In one large and handsome octavo volume, of over 600 large pages ; cloth, $4 ; leather, $5. ^MITH [HENRY H.), M.D., and JJORNER [ WILLIAM E.), M.D., Prof .of Surgery in the Univ. of Penna., Ac. Late Prof . of Anatomy in the Univ.ofPenna. AN ANATOMICAL ATLAS, Illustrative of the Structure of the Human Body. In one volume, large imperial octavo, cloth, with about six hundred and fifty beautiful figures. $4 50. s CHAFER [ED WARD ALBERT), M.D., Assistant Professor of Physiology in University ColUge, London. A COURSE OF PRACTICAL HISTOLOGY: Being an Introduction to the Use of the Microscope. In one handsome royal 12mo. volume of 304 pages, with numerous illustrations: cloth, $2 00. {Just Issued.) HORNER'S SPECIAL ANATOMY AND HISTOL- OGY. Eighth edition, extensively revised and modified. In 2 vols. 8vo., of over 1000 pages, with 320 wood-cuts : cloth, *6 00. SHARPEY AND QUAIN'S HUMAN ANATOMY. Revised, by Joseph Leidt, M.D.,Prof of Anat. in Univ. of Penn. In two octavo vols, of about ' 1300 pages, with 511 iUustrations Cloth, |6 00. BELLAMYS STUDENT'S GUIDE TO SURGICAL ANATOMY: A Text book for Students preparing for their Pass Examiration. With engiavinffs on wood. In one handsome royal 12mo. volume. Cloth, $2 2.1. CLELAND'S DIRECTORY FOR THE DISSECTION OF THE HUMAN BODY. In one small volume, ruyal 12mo. of 182 pages : cloth, *1 25. 8 Henry C. Lea's Publications — (Physiology). ffARPENTER ( WILLIAM B.), M. D., F. R. S., F.G.S., F.L.S., Registrar to University of London, etc. PRINCIPLES OF HUMAN PHYSIOLOGY; Edited by Henry Power, M.B. Lond., F.R.C.S.. Examiner in Natural Sciences, University of Oxford. Anew American from the Eighth Revised and Enlarged English Edition, with Noteg and Addi- tions, by Francis G. Smith, M.D., Professor of thelnstitutescf Medicine in the Univer- sity of Pennsylvania, etc. In one very large and handsome octavo volume, of 1088 pages, with twoplatesand873engravingson wood; cloth, $6 50; leather, $6 50. {Jnst Issued.) Thegreatwork, the crowning labor of the distinguished author, and through which so many generations of students have acquired their knowledge of Physiology, has been almost meta- morphosed in the effort to ac'apt it thoroughly to the requirements of modern science. Since the appearance of the last American edition, it has had several revision.s at the experienced hand of Mr. Power, who has modified and enlarged it so as to introduce all that is important in the investigations and discoveries of England, France, and Germany, resulting in an enlarge- ment of about one-fourth in the text. The series of illustrations has undergone a like revision, a large proportion of the former ones having been rejected, and the total number increased to nearly four hundred. The thorough revision which the work has so recently received in England, has rendered unnecessary any elaborate additions in this country, but the American Editor, Professor Smith, has introduced such matters as his long experience has shown him to be requisite for the student. Every care has been taken with the typographical execution, and the work i? presented, with its thousand closely, but clearly printed pages, as emphatically the text-book for the student and practitioner of medicine — the one in which, as heretofore, especial care is directed to show the applications of physiology in the various practical branches of medical science. Notwithstanding its very great enlargement, the price has not been in- creased, rendering this one of the cheapest works now before the profession. We have been agreeably surprised to find the vol- anie 60 complete in regard to the structure and func- tions of tbe nervous system in all its relations, a subject that, in many respects, is one of the most diffi- cult of all, in tbe whole range of physiology, upon which to produce a full and «ati8factory treati.se of the class to which the one before us belongs. The additions by the American editor give to the work as it is a considerable value beyond that of the last English edition. In conclusion, we can give our cor- dial recommendation to the work as it now appears. The editors have, with their additions to the only work on physiology in our language that, in the full- est sen^e of the word, is the production of a philoso- pher as well as a physiologist, brought it up as fully as could be expected, if not desired, to the standard of our knowledge of its subject at the present day. It will deservedly maintain the place it has always had iu the favor of ihe medical profession. — Journ. of Nervous and Mental Dumse, April, 1877. "Good wine needs no bush" says the proverb, and an old and faithful servant like the " big" Carpenter, as carefully brought down as this edition has been by Mr. Henry Power, needs little or no commendation by us. Such enormous advances have i-ecent'y been made iu our physiological knowledge, that what was perfectly new a year or two ago. looks now as if it had been a THceived and established fact for years. In this ency- clopaedic way it is unrivalled. Here, as it seems to us, is the great value of the book: one is safe in sending a student to it for information on almost any given subject, perfectly certain of the fulness of information it will convey, and well satisfied of the accuracy with which it will there be found stated. — London Med. Times and Gazette, Feb. 17, 1877. Thus fully are treated the structure and functions ol all the important organs of the body, while there are chapters on sleep and somnambulism ; chapterson eth nology, a full section on general ion. and abundant re- ferences to the curiosities of physiology, as the evolu tion of light, heat, electricity, etc. In short, this new edition of Carpenter is, as we have said at the start, a very encyclopedia of modern physiology. — The Glin- tc, Feb. 24, 1877. The merits of" Carpenter'sPhysiology" are so widely known and appreciated that we need only allude briefly to the fact that in the latest edi( ion will be found a com- prehensive embodiment of the results of recent physio los^icfil investigation. Care has been taken to preserve the practical character of the original work. In fact the entire work has been brought up to date, and bears evidence of the amount of labor that has been bestowed upon it by its distinguished editor, Mr. Henry Power. The American editor has made the latest additions, in order fully to cover the time that has elapsed since the last English edition. — N. Y. Med. Journal, ia^n, 1877. A more thorough work on physiology could not be found. In this all the facts discovered by the late re- searches are noticed, and neither student nor practi- tioner should be without this exhaustiTe treatise on &u important elementary branch of medicine. — Atlanta Med. and Surg. Journal, Dec. 1876. JZIRKES [WILLIAM SENHOUSE), M.D. A MANUAL OF PHYSIOLOGY. Edited by W. Morrant Baker, M.D., F.R.C.S. A new American from the eighth and improved London edition. With about two hundred and fifty illustrations. In one large and handsome royal 12mo. vol- ume. Cloth, $3 25; leather, $3 75. {Lately Issued.) On the whole, there is very little in the book | physiology which we have in our language. — N.Y. whicheitherthestudent or practitioner will not find i Med Record, April 15, 1873. of i>taciical value and consistent with our present I -,..■, ,e .^. t ■ , 4.,t4v knowledge of this rapidly changing science; and we ^ ^° !'« enlarged orm It is, in our opinion, etlll the have no h^'eeitation in expre-i^g our opinion that ^%' ^;«,f ;^° PVCr^I'n^^'o 7.7^^ ''' thestudent. this eighth edition is one of the best handbooks on I -PMa. Med. Times, Aug. .SO, 1873. HARTSHOKNE'S nANI>BOOK OF ANATOMY AND PHYSIOLOGY. Second edition, revised. In one roval 12mo. vol., with 220 woodcuts ; cloth, ♦i:.>. LEMMANN'S MANUAL OF CHEMICAL PHYSIOL- 0 JY. Traaslated from the German, with Notes and Additions, by J CnnsTOW Morris M.D. With illustrations on wood. In one octavo volume of 3.36 pages. Cloih, $2 2.-5. LEHMANN'S PHYSIOLOGICAL CHEMISTRY Com- plete in two large octavo volumes of 1200 pages, with 200 illustrati)n8; cloth, ^3. Henry C. Lea's Publications — (Physiology). nALTON (/. C), M.D., •^ Professor of Physiology in the. College of Physicians and Surgeons, New Torlt, Ac. A TREATISE ON HUMAN PHYSIOLOGY. Designed for the use of Studentsand Practitioners of Medicine. Sixth edition, thoroughly revised and enlarged, ■with three hundred and sixteen illustrations on wood. In one very beautiful octavo vol- ume, of over 800 pages. Cloth, $5 50 ; leather, $6 50. iJust Issued.) During the past few years several new works on phy-i This popular text-book on physiology comes to us in Biology, aiid new editions of old works, liave appeared ' competing for the favor of the medical student, but none will rival this new edition of Dalton. As now en- larged, it will be found also to be, in general, a satisfac- tory work of reference for the practitioner. — Chicago Med. Journ. and Examiner, Jan. 1 876. Prof. Dalton has discussed conflicting theories and conclusions regarding phy.siological (juestions with a fairness, a fulness, and a conciseness which lend fresh- ness and vigor to the entire book. But bis discussions have been so guarded by a refusal of admission to those speculative and theoretical explanations, which at best exist in the minds of observers themselves as only pro- babilities, that none of his readers need be led into gr,ave errors while makiug them a study. — The Medical Record, Feb. 19, 1876. The revision of this great work haSjbrought it forward with the physiological advances of the day, and renders it, as it has ever heen, the finest work for students ex- tant.— 2\"ashviUe Journ. of Med. and Surg., Jan. 1876. For clearness and perspicuity, Daltoii's Physiology commended itself to the student years ago, and was a pleasant relief from the verbose productions which it supplanted. Physiology has, however, made many ad- vances since then— and while the style has been pre- served intact, the work in the present edition has been brought up fully abreast of the times. The'new chemical notation and nomenclature have also been introduced into the present edition. Notwithstanding the multi- plicity of text-books on physiology, this will lose none of its old time popularity. The mechanical execution of the work is all that could be desired. — Peninsular Journal of Medicine, Dec. 1875. ts sixth edition with the addition of about fifty per cent, of new matter, chiefly in the departments of patho- logical chemistry and the nervous system, where the principal advances have been realized. With so tho- rough revision and additions, that keep the work well up to the times, its continued popularity may be confi- dently predicted, notwithstanding the competition it may encounter . The publisher's work is admirably done. — St. Louis Med. and Surg. Journ, Dec. 1875. We heartily welcome this, the sixth edition of this admirable text book, than which thereare noneof equal brevity more valuable. It iscordially recommended by the Professor of Physiology in theUniversity of Louisi- ana, as by all competent teachers in the United States, and wherever the Knglish language is read, this book has been appreciai.ed. The present edition, with its 316 admirably executed illustrations, has been carefully revised and very much enlarged, although its bulk does not seem perceptibly increased. — New Orleans Medical and Surgical Journal, March, 1876. The present edition is very much superior to every other, not only in that it brings the subject up to the times, but that i*^. do<«s so more fully and satisfactorily than any previous edition. Take it altogether it remains inourhumbleopinion,thebest text book on physiology in any land orlant;uage. — The Clinic. Nov. 6, 1875. As a whole, we cordially recommend the work as a text-book for the student, and as one of the best. — The Journal of Nervous and Mental Disease, Jan. 1876. Still holds its position as a masterpiece of lucid writ- in?, and is, we believe, on the whole, the best book to place in the hands of the student. — London Students' Journal. fjLASSEN {ALEXANDER), ^^ Professor in the Royal Polytechnic School, Aixla-Chapdle. ELEMENTARY QUANTITATIVE ANALYSIS. Translated with notes and additions by Edgar F. Smith, Ph.D., Assistant Prof, of Chemistry in the Towne Scientific School, Univ. of Penna. In one handsome royal 12mo. volume, of 324 pages, with illustrations; cloth, $2 00. {Just Ready.) It is probably the bast manual of an elementary | advancing to the analysis of minerals and such pro- nature extant, insomuch as its methods are the best. I ducts as are met with in applied chemistry. It is It teaches by examples, commencing with single j an indi.spen«able book for students in chemistry. — determinations, followed by separations, and then i Boston Journ. of Chemistry, Oct. 1878. rfALLOWAY [ROBERT), F.C.S., ^-^ Prof of Applied Chemtttry in the Royal College of Science for Ireland, etc. A MANUAL OF QUALITATH^E ANALYSIS. From the Fifth Lon- don Edition. In one neat royal 12mo. volume, with illustrations ; cloth, $2 75. {Lately Issued.) jyo WMAN [JOHN E.) , M.D. INTRODUCTION TO PRACTICAL CHEMISTRY, INCLUDING ANALYSIS. Sixth American, from the sixth and revised London edition. With numer- * ous illustrations. In one neat v61., royal 12mo., cloth, $2 25. J^Y THE SAME AUTHOR. PRACTICAL HANDBOOK OF MRDICAL CHEMISTRY. New edition. In one neat volume, royal 12rao. {Preparing.) E W EMSEiV{IRA), M.D., Ph.D., Professor of Chemistry in the Johns Hopkins University, Baltimore. PRINCIPLES OF THEORETICAL CIIH]MISTllY, with special reference to the Constitution of Chemical Compounds. In one handsome royal 12mo. vol. of over 232 pages: cloth, $1 50. {Just Issued.) 'OHLER AND FITTIG. OUTLINES OF ORGANIC CHEMISTRY. Translated with Ad- ditions from the Eighth German Ed. By Ira. Rrmskn, M.D., Ph.D., Prof, of Chem- andPhysics in Williams College, Mass. In one volume, royal 12mo.of 550 pp., cloth, $3, 10 Henry C. Lea's Publications — {Chemistry] JPOWNES [GEORGE), Ph.D. A MANUAL OF ELEMENTARY CHEMISTRY; Theoretical and Practical. Revised and corrected by Uknrv Watts, B.A., F.R.S., author of "A Diction- ary of Chemistry," etc. With a colored plate, and one hundred and seventy-seven illus- trations. A new American, from thi twelfth and enlarged London edition. Edited by Robert Bridges, M.D. In one large royal 12mo. volume, of over 1000 pages j cloth, $2 75 ; leather, $3 25. {Just Ready.) Two careful revisions by Mr. Watts, since the appearance of the last American edition of "Fownes," have so enlarged the work that in England it has been divided into two volumes. In reprinting it, by the use of a small and exceedingly clear type, cast for the purpose, it has been found possible to comprise the whole, without omission, in one volume, not unhandy for study and reference. The enlargement of the work has induced the American Editor to confine his additions to the narrowest compass, and he has accordingly inserted only such discoveries as have been an- nounced since the very recent appearance of the work in England, and has added the standards in popular use to the Decimal and Centigrade systems employed in the original. Among the additions to this edition will be found a very handsome colored plate, representing a number of spectra in the spectroscope. Every care has been taken in the typographical execu- tion to render the volume worthy in every respect of its high reputation and extended use, and though it has been enlarged by more than one hundred and fifty pages, its very moderate price will still maintain it as one of the cheapest volumes accessible to the chemical student. This work, inorganic and organic, i.s complete in one convenient volume. In its earliest editions it was fully up to the latest advancements and theo- ries of that time. In its present form, it presents, in a remarkably convenient and satisfactory man- ner, the principles and leading facts of the chemistry of to-day. Concerning the manner in which the various subjects are treated, much deserves to be said, and mostly, too, in praise of the book. A re- view of such a work as Fownes's Chemistry within the limits of a book-notice for a medical weekly is simply out of the question. — Cincinnati Lanctt and QHnic, Dec. 14, 1878. When we state that, in our opinion, the present edition sustains in every respect the high reputation which its predecessors have acquired and eujoyed, we express therewith our full belief in its intrinsic value as a text-book and work of reference. — Am. Journ. of Pharm., Aug. 1878. The conscientious care which has been bestowed upon it by the American and English editors renders it still, perhaps, the bes^t book for the student and the practitioner who would keep alive the acquisitions of his student days. It has, indeed, reached a some- what formidable magnitude with its more than a thousand pages, but with less than this no fair repre- sentation of chemistry as it now is can be given. The type is small but very clear, and the sections are very lucidly arranged to facilitate study and reference.— Med. and Surg. Reporter, Aug 3, 1878. The work is too well known to American students to need any extended notice; sallice it to say that the revi.-ion by the English editor has been faithfully done, and that Professor Bridges has added some fresh and valuable matter, especially in the inor- ganic chemistry. The book has always been a fa- vorite in this country, and in its new shape bids fair to retain all its former prtsiig'e. — Boston Jour, of Chemistry , Aug. 1878. It will be entirely unnecessary for us to make any remarks relating to the general character of Fownes' Manual. For over twenty years it has held the fore- most place as a text-book, and the elaborate and thorough revisions which have been made from time to time leavelittlechauce for any wide awake rival to step before ii.— Canadian Pharm. Jour., Aug. 187S. As a manual of chemistry it is without a superior in the language.— ilfd. Med. Jour., Aug. 1878. ATTFIELD {JOHN), Ph.D., Professor of Practical Chemistry to the Pharmaceutical Society of Great Britain, Sec. CHEMISTRY, GENERAL, MEDICAL, AND PHARMACEUTICAL; including the Chemistry of the U. S. Pharmacopoeia. A Manual of the General Principles of the Science, and their Application to Medicine and Pharmacy. Eighth edition revised by the author. In one handsome royal 12mo. volume of 700 pages, with illustrations. Cloth, $2 50 ; leather, $3 00. {Jjist Ready.) We have repeatedly expressed our favorable f of chemistry in all the medical colleges in the opinion of this work, and on the appearance of a i United States. The present edition contains such new edition of it, little remains for us to say, ex- | alterations and additions as seemed necessary for cept that we expect this eighth edition to be as indispensable to us as the seventh and previous editions have been. While the general plan and arrangement have been adhered to, new matter has been added covering the observations made since the former edition The present differs from the preceding one chiefly in these alterations and in about ten pages of useful tables added in the appendix —Am. Jour, of Pharmacy, May, 18'9. A standard work like Attfield's Chemistry need only be mentioned by its name, without further comments The present edition cantains such al terations and additions as seemed necessary for the demonstration of the latest developments of chemical principles, and the latest applications of chemistry to pharmacy. The author has bestowed ardnois labor on the revision, and the ex'ent of the information thus introduced may be estimated from the fact that the index <*outains three hun- dred new references relating to additional mate- rial.—i>)'Mgrgriirf^' Circular and Chemical Gazntte, May, 1879. This very popular and meritorious work has now reached its eighth edition, which fact speaks in the highest terms in commendation of its excel lence. It has now become the principal text-book the demonstration of the latest developments of chemical principles, and the latesc applications of chemistry to pharmacy. It is scarcely neccsary for us to say that it exhibits chemistry in its pre- sent advanced si»,ie.— Cincinnati Medical Ntws, April, 1^79. The popularity which this work has enjoyed is owing to the original and clear disposition of the facts of the science, the accuracy of the details, and the omission of much which freights many treatises heavily without bringing corresponding instruction to the reader. Dr. Attfield writes for students, and primarily for medical students; he always has an eye to the pharmacopoeia and its officinal prepara- tions; and he is continually putting the matter in the text so that it responds to the questions with which each section is provided. Thus the student learns easily, and can always refresh and test his knowledge.— 3f«;rf andSurff. Reporter, Apriil9,'79. We noticed only about two years and a half ago the publication of the preceding edition, and re- marked upon the exceptionally valuable character of the work. The work now iaclndes the whole of the chemistry of the pharmacopoeia of the United States, Great Britain, and India.— i^Teto Remedies, May, 1879. Henry C. Lea's Publications — {Chemistry). 11 F ^ARQUHARSON {ROBERT), M.D., Lecturer on Materia Medica at St. Mary'' s Hospital Medical School. GUIDE TO THERAPEUTICS AND MATERIA MEDICA. Se- cond American edition, revised by the Author. Enlarged and adapted to the U. S. Pharmacopoeia. By Franic. WoODBunv, M.D. In one neat rojal 12mo. volume of 498 pages : cloth, $2.25. (Just Ready.) This work contaiDS in moderate compass such ■well-digested facts concerniug the physiologiPal and therapeutical action of rencedies as are reason- ably established up to the present time. By a con- venient arrangement the correspondiEg effects of each article in health and disease are presented in parallel columns, not only rendering reference easier, but also impressing the facts more strongly upon the mind of the reader. The hook has been adapted to the wants of the American student, and copious notes have been introduced, embodying the latest revision of tie Pharmacopoeia, together with the antidotes to the more prominent poisons, and such of the newer remedial agents as seemed neces- The appearance of a new edition of this conve- nient and handy book in less than two years may certainly be taken as an indication of its useful ness. Its convenient arrangement, and its terse- nefis, and, at the same time, completeness of the information given, make it a handy book of refer e ace. —.4m. Journ. of Pharmacy, June 1S79. The early appearance of a second eiition of Dr. Farquharson's work bears sufficient testimony to the appreciation of it by American readers. The plan is such as to bring the character and action of drugs to the eye and mind with clearness The care with which both author and editor have done their work is conspicuous on every page. —ifed.ancij gary co the completeness of the work. Tables of Surg. Reporter, May 31, 1S79. weights and measures, and a good alphabetical in- The second edition, enlarged and revised, is a ! ^^^> end the ^olnm^.-Drnggists' Circular and happy medium between the first edition, which ! Ohemical Gazette, June, 1S79. was rather too brief on some important matters, and the larga octavos of Wood and Birtbolow. It is brought up to the most recent researches, one note referring to an article published in April of this year. The favorable reception accorded it, shown by this reissue in two years, was one well iQetUQdi.—Louismlle Med. Neios, June 7, 1S79. It is a pleasure to think that the rapidity with which a second edition is demanded may be taken as an indication that the sense of appreciation of the value of reliable information regarding the use of remedies i- not entirely overwhelmed in the cultiva- tion of pathological studies, characteristic of the pre- sent day. This work certainly merits the success it has so quickly achieved.— .ft^eio Remedies, July, '79. B LOXAM iC.L.), Profes-ior of Chemistry in King^s College, London. CHEMISTRY, INORGANIC AND ORGANIC. From the Second Lon- don Edition. In one very handsome octavo volume, of 700 pages, with about 300 illus- Cloth, $4 00; leather, $5 00 work a eompleteand most excel- trations, We have in th lent text-book for the use of schools, and can heart- ily recommend it as such. — Boston Med. and Surg. Journ., May 28, 1S74. The above is the title of a work which we can most conscientiously recommend to students of chemis- try. It is as easy as a work on chemi.-try could be made, at thesame time that it preseutsa full account of thatscience as it now stands. We have spoken of the work as admirably adapted to the wants of students; it is quite as well suited to the require- ments of practitioners who wish to review their chemistry, or have occasion to refresh their memo- ries on any point relating to it. In a word, it is a book to be read by all who wish to know what is thpchemistry of the present day. — American Prae titioner, Nov. 1873. {^Lately Issued.) It would be difficult for a practical chemist and teacher to find any material fault with this most ad- mirable treatise. The author has given us almost a cj clopffidia within the limits of a convenient volume, and has done so without penning the useless para- graphs too commonly making up a great part of the bulk of many cumbrous works. The progressive scientist is not disappointed when he looks for the record of new and valuable processes acd discover- ies, while the cautious conservative does not find its pages monopolized by uncertain theories and specu- lations. A peculiar point of excellence is the crys- tallized form of expression in which great truths are expressed in very short paragraphs. One is surprised at the brief space allotted to an important topic, and yet, after reading it, he feels that little, if any more should have been said. Altogether, it is seldom yoi see a text-book so nearly faultless. — Cincinnati Lancet, Nov. 1S73. rfLOWES (FRANK), D.Sc. London. ^^ Senior Science- Master otthe HigkSchool, Xewcastle-under Lyme, etc. AN ELEMENTARY TREATISE ON PRACTICAL CHEMISTRY AND QUALITATIVE INORGANIC ANALYSIS. Specially adapted for Use in the Laboratories of Schools and Colleges and by Beginners. From the Second and Revised English Edition, with about fifty illustrations on wood. In one very handsome royal 12mo. volume of 372 pages : cloth, $2 50. {Now Ready.) It is short, concise, and eminently practical. We therefore heartily commend it to students, and e^^pe- cially to those who are obliged to dispense with a master. Of course, a teacher is in every way desi- rable, but a good degree of technical skill and prac- tical knowledge can be attained with no other instructor than the very valuable handbook now under consideration. — St. Louis Clin. Record, Oct. 1877. The work is so written and arranged that it can be comprehended by the student without a teacher, and the descriptions and directions forthe various work are so simple, and yet concise, as to be interesting and intellig'ble. The work is unincumbered with theoretical deductions, dealing wholly with the practical matter, which it is the aim of this compre- hensive textbook to impart. The accuracy of the analytical methods are vouched for from the fact that they have all been worked through by the author and the members of his class, from the printed text. We can heartily recommend the work to the student of chemistry as being a reliable acd comprehensive one. — Druggists' Advertiser, Oct. 15, 1877. KNAPP'S TECHNOLOGY; or Chemistry Applied to .the Arts, and to Manufactures. With American additions by Prof. Walter R. Johx.son. In two very handsome octavo volumes, with 500 wood engravings, cloth, $6 00. 12 Henry C. Lea's Publications — {Mat.. 3Ied. and Therapeutics). pARRISH {EDWARD), Late Professor of Materia Medica in the Philadelphia College of Pharmacy. A TREATISE ON PHARMACY. Designed as a Text-Book for the Student, and as a Guide for the Physician and Pharmaceutist. With many Formulae and Prescriptions. Fourth Edition, thoroughly revised, by Thomas S. Wiegand. In one handsome octavo volume of 977 pages, with 280 illustrations ; cloth. $6 50 ; leather, $6 50. {Lately Issjied.) Of Dr. Parrish's great work on pharmacy it only l the work, not only to pharmacist?, but also to the remains to be said that the editor has accomplished multitude of medical practitioners who are obliged his work so well as to maintain, in this fourth edi- ; to compound their own medicines. It will ever hold tion, the high standard of excellence which it bad an honored place on our own bookshelves. — Dublin attained in previous editions, under the editorship of, Med. Press and Circular, Aug. 12, 1874. Its accomplished author. This has not been accom plished without much labor, and many additionsand Improvements, involving changes in the ariange- mentof the several parts of the work, and the addi- tion of much new matter. With the modifications thus effected it constitutes, as now presented, a co We expressed our opinion of a former edition in terms of unqualified praise, and we are in no mood to detract from that opinion in reference to the pre- sent edition, the preparation of which has fallen into competent hands. It is a book with which no pharma- pendium of the science and art indispensable to the ^'^^^*° dispense, and from which no physician can - ' fail to derive much information of value to him in practice.— Pa ci/?c Med. and Surg . Journ. , June, '74. pharmacist, and of the utmost value to every practitioner of medicine desirous of familiarizing himself with the pharmaceutical preparation of the articles which he prescribes for his patients. — Chi- cago Med. Journ., July, 1S74. The work is eminently practical, and has the rare Perhaps one, if not the most important book upon pharmacy which has appeared in the English lan- guage has emanated from the transatlantic press. "Parrish's Pharmacy" is a well-known work on this merit of being readable and interesting, while itpre- j side of the water, and the factshowsns that a really srves astrictly scientificcharacter. The whole work reflects the greatest credit on author, editor, and pub- lisher. Itwillconveysomeideaof the liberality which has been bestowed upon itsproduction when we men- tion that thereare no less than 280 carefully executed illustrations. In conclusion, we heartily recommend useful work never becomes merely local in its fame. Thanks to the judicious editing of Mr. Wiegand, the posthumous edition of " Parrish" has been saved to the public with all the mature experience of its au- thor, and perhaps none the worse for a dash of new blood.— io7id. Pharm. Journal, Oct. 17, 1874. S TJLLE [ALFRED), M. D., Professor of Theory and Practice of Medicine in the University of Penna. THERAPEUTICS AND MATERIA MEDICA ; a Systematic Treatise on the Action and Uses of Medicinal Agents, including their Description and History. Fourth edition, revised and enlarged. In two large and handsome 8vo. vols, of about 2000 pages. Cloth, $10; leather, $12. (Lately Issued.) of the present edition, a whole cyclopaedia of thera- peutics.—O/ucap'o Medical Journal, Feb. 1875. The rapid exhaustion of three editions and the uni- versal favor with which the work has been received by the medical profession, are sufficient proof of its excellence as a repertory of practical and useful In- formation for the physician. The edition before us fully sustain.^ this verdict, as the work has been care- fully revised and in some portions rewritten, bring- ing it up to the present time by the admission of chloral and crotonchloral, nitrite of ainyl, bichlo- ride of methylene, methylic ether, lithium com- pounds, gelseminnm, and other remedies.— .4m. Journ. of Pharmacy, Feb. 1875. We can hardly admit that it has a rival in the multitude of its citations and the fulness of its re- search into clinical histories, and we must assign it a place in the physician's library; not, indeed, as fully representing the present state of knowledge in pharmacodynamics, but as by far the most complete treatise upon the clinical and practical side of the question. — Boston Med. and. Surg. Journal, Nov. 5, 1874. It is unnecessary to do much more than to an- nounce the appearance of the fourth edition of this well known and excellent work. — Brit, and For. Med.-Chir. Review, Oct. 1875. For all who desire a complete work on therapeutics and materia medica for reference, in casesiuvolving medico-legal questions, as well as for information concerning remedial agents, Dr. Still^'s is ^^par ex- cellence'^ the work. The work being out of print, by the exhaustion of former editions, the author has laid the profession under renewed obligations, by the careful revision, importantadditions, and timely re issuing a work not exactly supplemented by any other in the English language, if in any language. The mechanical execution handsomely sustains the well-known skill and good taste of the publisher. — St. Louis Med. and Surg. Journal, Dec. 1874. From the publication of the first edition "Still^'s Therapeutics" has been one of the classics; its ab- sence from our libraries would create a vacuum which could be filled by no other work in the lan- guage, and its presence supplies, in the two volumes QRIFFITH [ROBERT E.), M.D. A UNIVERSAL FORMULARY, Containing the Methods of Prepar- ing and Administering OfBcinal and other Medicines. The whole adapted to Physiciar-s and Pharmaceutists. Third edition, thoroughly revised, with numerous additions, bj John M. Maisch, Professor ofMateria Medica in the Philadelphia College of Pharmacy. In one large and handsome octavo volume of about 800 pp., cl., $4 50 ; leather, $5 50. (Lately Issued.) To the druggist a good formulary is simply indis- pensable, and perhaps no formulary has been more msively used than the well-known work before us. Many physicians have to officiate, also, as drug- gist.?. This is true especially of the country physi- cian, and a work which shall teach hira the means by which to administer or combine his remedies in the most efficacious and pleasant manner, will al- ways hold its place upon his shelf. A formulary of this kind is of benefit also to the city physician in largest practice,— Omcfnnofi Qlinic, Feb. 21, 1874. A more complete formulary than it is in its pres- ent form the pharmacist or physician could hardly desire. To the first some such work is indispensa- ble, and it is hardly les.^i essential to the practitioner who compounds his own medicines. Much of what is contained in the introduction ought to be com- mitted to memory by every student of medicine. As a help to physicians it will be found invaluable, and doubtle.ss will make its way into libraries not already supplied with a standard work of the kind. — The American Practitioner ,LoviisviUe, July, '74. Henry C. Lea's Publications— (Jia^. MeA, and Therapeutics.) 13 ^TILLE ,E (ALFRED), M.D,LL.D., and JlfAISCH {JOHN M.), Ph.D., *^ Prof of Theory and Practice, of Medicine -^^ Prof, of Mat. Med. and Bot. in Phila. and of Clinical Med. in Univ. of Pa. Coll. Pharmacy, Secy, to the American Pharmaceutical Axsociation. THE NATIONAL DISPENSATORY: Containinp: the Natural History, Chemistry, Pharmacy, Actions and Uses of Medicines, including those recognized in the Pharmacopoeias of the United States and Great Britain. In one very handsome octavo volume of 1628 paces, virith over 200 illustrations. Extra cloth, $6 76 ; leather, raised bands, $7 50. {Notv Ready) EXTRACT FROM THE PREFACE. " In the rapid progress of modern research, few subjects have of late years received greater acces- sions of facts than the group of sciences connected with materia mediea and therapeutics. The new resources thus placed at the cotutnand of the pharmaceutist and physician have seemed to the authors to justify an attempt to make, from the advanced stand-poini of the present day, a concise but complete statement of all that is of practical importance to both professions — a digest in which that which is old and that which is new shall be so brought t'^gether as to give to the reader, within the most moderate practicable compass, all the details in pharmacology, pharmacy, and thera- peutics, which he is likely to need in his daily avocations. In the almost intinite accumulation of material, this has required a careful and conscientious sifting to discard that which is obsolete, untrustworthy, or comparatively trivial, without impairing the practical completeness of the work. Th.it they have wholly accomplished their object the authors do not venture to claim ; but they can say that years of constant labor have been devoted to the task of producing a work to which the inquirer may refer with the certainty of finding everything which experience has stored up as worthy of confidence in the subjects embraced within its scope." We intend to draw the attention of our brother l the preface, and now that it has been published and pharmacists to this publication, wliich cannot fail j opens to us its vast stores of information, we may to exercise a widespread and m ij ked influence upon add that it was almost a necess^itv ; and this we say the discharge of tbe duties of their vocation. '1 be i without meaning to impugn the great excellence of material embodied in the work is truly immense, the works of similar character ti hich have precfded as shown alone by the almost countless number if | it. All of the descriptions, whether medical, botun- fiubjects treated. We congratulate the authors upon j ical, or pharmaceutical, are clear, in good English, their success in having brought to a close a work i and unencumbered with obsolete and unintelligible which must inevitably take its placeas one of the terms. Those portions which have reference to most important con ributious to medical and phar- maceutical literature. — ^m. Journ. o/ Pharm, May, 1879. The association of such distinguished authors as Professors Still6 and Maisch in tbe composition of a work of this character has excited the strongest in- terest and the highest expectati. ns in the mind of every physician and pharmacist in the country. For once we can truly say that the promise of ex- cellence hai been fufllled to the letter, and the Na- tional Di.'-pensatory has come almost perfect from therapeutics form a convenient treatise on that sub- ject, and are made the more valuable and available by a complete therapeutical index. The purely pharmacal part is as perfect as it is possible to make it, and less could not have been expected when we consider Prof. Maisch's great qualifications for work of that kind.— iV. 0 Med. Journ., March, 1S79. The therapeutic part is as rich as would he ex- pected of the author of the most comprehensive work on the subject in our language. The physiological effects of drugs receive due attention, and their iu- the hands of its makers. The entire work is a most j fiuence over disease is stated succinctly. For the excellent one and cannot fail to satisfy the pur- j ta.^k of wiaaowing the immense accumulation of chaser. We can couj-cientious y recommend it f) | periodical literature, the experience and matured every student and practitioner of medicine and j judgment of Prof. Stille were emiuen'ly fitted. No pharmacy.— ,S^ Louis Clinical Record, Apr 1879. i pharmacist or doctor will repent the purchase of a This magnificent work has at last arrived, and ! Jook which is at once a trea'.ury of facts and the we are at floss for words to express our apprecia- fe^^ ^^^Jr^ri'i^g ^ -Louz.vtlle Med. tionand togi^e our readers au idea of it The sub- '^*^'^' ^^^arcn zj, i6/9. jeBt-matter is brought to date, showiug that it has The pharmaceutical world has for a long time been the unceasing aim of the authors to supply a j been ou the quivive, in expectation of the forthcom- much needed book, one that will contain all the im- | ,„, Dispensatory by Profs. Stillo and Maisch, who portaat facts, and not dwell upon points that are of i have acquired fuch a reputation in their re>peclive comparatively little interest to any but a specially Departments that nothing but a satisfactory work interested student While this work, ou account of | could be expected ; this expectation has been quite its conciseness, is adapted to the pharmacal student, | realized. We have examined the work with some it is equally adapted to the medica| student and j care, and are very much plea.^ed that we can pro- practitioner by its well arranged therapeutical in- nounce it to be reliable, comprehensive, and includ- dex containingabont 37,o0 references, while the ma- I ing the latest re)'earche8 available to its authors, teria mediea index embraces about 10 400. The This is more particularly true as regards the portion physician sees at a glance all medicines tha^. are j devoted to pharmaceutical subjects. We are fully used for any certain class of disease.— GAicapoP/iar- ! jQstifled in stating that it is, taken altogether. macist and Chemiat, April, 1S79. The present Dispensatory is arranged in alpha- betical order from the commencement, the recent hdvaaces in chemistry are mentioned, and an effort of the most important and creditable publications which have of late been issued by the American press. It will be an indispensable reference book both for the pharmacist and the physician.— ^Veio made to include the late novelties in the review of j Remedies, April, 1879. the resources of the physician. This is carried out | ^ careful examination of the work calls forth un- with that sound conservative judgment which cha- | qualified praise for its excellent arran«ement, full racterizes all Prof. StiUe a wori. The chemical i yet concise information, its careful adherence to the and pharmaceutical sections have, we may suppose, . ^^st authority on each particular topic, as well as received the especial care of Prof. Maisch; and as t^e entire ehmiuation of all unnecessary and obso- he is facile jirincps in that branch, nothing can be ! lete data and particulars. The arrangement of all said of them except in praise.— ^eci. and Sttrg. Re- \ topics is purely alphabetical, and with surprising porter April o, 1879, fidelity to the wants both of th^^physiciau and phar- It has been prepared by two gentlemen whose j maceutist. New remedies which have come Into learning fully qualified them for the difllcult task, i recent use are here found noticed, with .'•uch facts and whose eminence entitles them to be heard with i as have been collated from careful investigation. — the respect and attention due to authority. The ; Druggists' Circular and Chemical Gazette, March, •'raisou d'etre" of the book is modestly stated in \ 1S79. 14 Henry C. Lea's Publications— (Pa/7?oZof;^, ^c). nORNIL (F.), AND TfANVIER (L.), Prof, in the Faculty of Med , Paris. "^ *' Prof in the College of France. MANUAL OF PATHOLOGICAL HISTOLOGY. Translated, with Notes and Additions, by E. 0. Siiakespeahe, M.D., Pathologist and Ophthalmic Surgeon to Philada. Hospital, Lecturer on Refrflclion and Operative Ophthalmic Surgery in Univ. of Penna., and by Hebtrv C. Simrs. M D., Demonstratrr of Pathological Histology in the Univ. of Pa. In one very handsome octavo volume of about 600 pages, with over 300 illustrations. (iSkurtly.) So much has been done of late years in the elucidation of pathology by means of the micro- scope, and this subject now occupies so prominenta position as one of the most important branches of medical science, that the American profession cannot fail to welcome atranslation of the pre- sent work, wnich, through its own merits and through the well-known reputation of its distin- guished authors, is regarded in Europe as the standard text-book and work of reference in its department. Such investigations and discoveries as have been made since its appearance will be introduced by the translator, and the work is confidently expected to assume in this country the same position which has been so universally accorded to it abroad. PENWJCK {SAMUEL), M.D., -*■ Assistant Physician to the London Hospitals THE STUDENT'S GUIDE TO MEDICAL DIAGNOSIS. From the Third Revised and Enlarged English Edition. With eighty-four illustrations on wood. In one very handsome volume, royal 12mo., cloth, $2 25. {Jtist Issued.) Of the mpny guid'^-books on medical dlHgnobis, are few books of this sizeon practical medicine that claimed to be written for the special in.struction of j contain bo much and convey it so well as che volume students, this Is the best. Theauthor is evidently a | before us. It is a book we can sincerely recommend well-read and accomplished physiciau.and he knows | to the student for direct instruction, and to thejprac- how to teach practical medicine. The charm of sim- I titioner as a ready and useful aid to his meraorj.— plicity is not thelea»=t int<>restiagfeatnreiu the man- Am. Journ. of Syphilography, Jan. 1874. ner in which Dr. Fen wick convey. •> instruction. The re ' G KEEN {T. HENRY), M.D., Lecturer on Pathology and Morbid Anatomy at Charing-Crofis Hospital Medical School, etc. PATHOLOGY AND MORBID ANATOMY. Third American, from the Fourth and Enlarged and Revised English Edition. In one very handsome octavo volume of 332 pages, with 132 illustrations; cloth, $2 25. (Just Ready.) ciently immerous, and usually well made. In the present edition, such new matter has been added as was necessary to embrace the later results in patho- logical research. No doubt it will continue to enjoy the favor it has received at the hands of the profes- sion.— Med and Surg. Reporter, Feb. 1, 1S79. For practical, ordinary daily use, this is undoubt- edly the best treatise that is offered to students of This is unquestionably one of the best manuals on the subject of pathology and morbid anatomy that can be placed in the student's hands, and we are glad to see it kept up to the times by new editioos. Each edition is carefully revised by the author, with the view of makiug it include the most recent ad- vances in pathology, and of omitting whatever may have become obsolete. — X. Y. Med. Jour., Feb. 1879. The treatise of Dr. Green is compact, clearly ex- pathology and morbid anatomy. — Cincinnati Lan pressf d, up to the times, and popular as a text-book, { cet and Clinic, Feb. 8, 1S79. both in England and America. The cuts are suffi- 1 JD AVIS {NATHAN S.), Prof, of Principles and Practice of Medicine, etc., in Chicago Med. College. CLINICAL LECTURES OX VARIOUS IMPORTANT DISEASES; being a collection of the Clinical Lectures delivered in the Medical Wards of Mercy Hos- pital, Chicago. Edited by Frank H. Davls, M.D. Second edition, enlarged. In one handsome roy^l 12mo. volume. Cloth, $1 75. {Lately Issued.) WHAT TO OBSERVE AT THE BEDSIDE axd AFTER Death in Medical Casks. From the second Lon- don edition. 1 vol royal 12mo., cloth. $100. CHRISTISON'SDISPENSATORT. With copious ad- ditions, and '2i;3 large wood engravings. By R. KoLKSFiRLD GRIFFITH, M.D. One vol. Svo., pp. 1000, cloth. $4 00. CARPENTER'S PRIZE ESSAY ON THE USE OF Alcoholic Liquors in Health and Disease. New edition, with a Preface by D. F. Condie, M.D., and explanationsof scientiflcwords. In oneneatl2mo. volume, pp. 178, cloth. 60 cents. O LUGE'S ATLAS OF PATHOLOGICAL HISTOLOGY Translated, with Notes and Additions, by Joseph Leidt, M. D. In one volume, very large imperial quarto, with 320 copper-plate figures, plain and colored, cloth. |l?00. LA ROCHE ON YELLOW FEVER, considered in its Historical, Pathological. Etiological, and Thera peutical Relations. In two large and handsome octavo volumes of nearly loOO pp , cloth. $7 00. HOLLAND'S MEDICAL NOTES AND REFLEC- TI0N8. 1 vol. 8vo., pp. 500, cloth. $3 60. BARLOW'S MANUAL OF THE PRACTICE OP MEDICINE. With Additions by D. F. Condif, M D. 1 vol. 8vo., pp. 600, cloth. $2 50. TODD'SCLINICAL LECTURES ON CERTAIN ACUTB Diseases. In one neat octavo volume, of 320 pp , cloth. $2 60. STURGES'S INTRODUCTION TO THE STUDY OF CLINICAL MEDICINE. Being a Guide to the In- vestigation of Disease. In one handsome 12rao. volume, cloth, $1 2.3. {Lately Issxied.) STOKES' LECTURES ON FEVER. Edited by John William Moork, M.D. , Assistant Physician to the Cork Street Fever Hospital. In one neat Svo. volume, cloth, .$2 00. {Juat Issued.) THE CYCL0P.T5DIA OF PRACTICAL MEDICINE: comprising Treatises on the Nature and Treatment of Diseases, Materia Medica and Therapeutics, Dis- eases of Women and Children, .Medical Jurispru- dence, etc. etc. By Do'NOL.moN, Fokbks, Twkedie, and CoNOLLV. In' four large super-royal octavo volumes, of 8'2.54 double-columned p;ige.«, strongly and handsomely bound in leather, $15; cloth, $11. Henry C. Lea's Publications — {Practice of Medicine), 15 fpLINT (AUSTIN), M.D., -^ Professor of the Priyiciples and Practice of Medicine in Sellevue Med. College, N. Y. A TREATISE ON THE PRINCIPLES AND PRACTICE OF MEDICINE ; designed for the use of Students and Practitioners of Medicine. Fourth edition, revised and enlarged. In one large and closely printed octavo volume of about 1100 pp.; cloth, $6 00 J or strongly bound in leather, with raised bands, $7 00. (l.ate/y Issued. ) By common consentof the English and American medical press, this work has been assigned to the highest position as a complete and compendious text-book on the most advanced condi- tion of medical science. At the very moderate price at which it is offered it will be found one of the cheapest volumes now before the profession. This excellent treatise on medicine lias acquired His own clinical studips and the latest contribu- foritselfin the United States a reputation similar to tions tomf^dical literature both in this country and thateuioyed in England by the admirable lectures in Europe, have received careful attention, to that of Sir Thomas Watson. We have referred to many | some portions have been entirely rewritten, and of the most important chapters, and find the re^i- j about seventy pages of new matter have been ad- sion spoken of in the preface is a genuine one, and , ded. — Chicago Mtd Jour., June, 1873. thattheauthorhasvery fairly brought u^^^^^^^^^ | ^ surpassed as a text-book for stu- to thelevel oftheknowledgeof thepresent daj. The of ready reference for practition- workhasthispatrecommendation thatU s^^^^ The force of its logic, its simple and practical volume,andthereforewillnotDesoternfyiugtothe teachings, have left it without a rival in the field N. Y.—Med. Record, Sept. 1.5, 1874. student as the bulky volumes which several of our En:?lish text-books of medicine have developed in to. —British and Foreign Med.-Chir. Rev., Jan. 187^. It is of course unnecessary tointroduce or eulogize this now standard treatit^e. The present edition has been enlarged and revised to bring it up to the author's present level of experience and reading. It is given to very few men to tread in the steps Of Austin Flint, whose single volume on medicine though here and there defective, is a masterpiece oj- lucid condensation and of general grasp of an enor. mously wide subject. — Lond. Practitiojier.Dec.'lS^ -nY THE SAME AUTHOH. CLINICAL MEDICINE; a Systematic Treatise on the Diagnosis and Treatment of Diseases. Designed for Students and Practitioners of Medicine. In one large and handsome octavo volume of about 900 pages, {hi Press.) It has been the object of the author in this volume to present the scierce and art of medicine in their most practical aspect, adapted to the necessities of the student and physician in the daily routine of duties at the bedside. By avoiding the discussion of questions relating to pathology and etiology, space is gained for the thorough consideration of diagnosis and treat- ment, embracing many points which escape attention in the ordinary text- books. In the arrange- ment of the work, diseases are classed according to the system of organs primarily affected : and affections closely related are grouped together so as to elucidate their differentiation, and the appropriate treatment is pointed out for each. The preparation of the work has occupied the author for several years, and is presented as embodying the results of prolonged observation and experience under opportunities more extensive than often fall to the lot of the physician. JDY THE SAME AUTHOR. ESSAYS ON CONSERVATIVE MEDICINE AND KINDRED TOPICS. In one very handsome royal 12rao. volume. Cloth, $1 38. {Just Issued.) fJARTSHOENE [HENRY], M.D., ■»-*• Professor of Hygiene in the University of Pennsylvania. ESSENTIALS OF THE PRINCIPLES AND PRACTICE OF MEDI- CINE. A handy-book forStudents and Practitioners. Fourth edition, revised and im- proved. With about one hundred illustrations. In one handsome royal ]2mo. volume, of about 550 pages, cloth, $2 63 ; half bound, $2 88, {Lately Issued.) As ahandbook, which clearly sets forth theBssEN- i book, it cannot be improved upon. — Chicago Med. TI.4I.S of the PRINCIPLES ANi) PRACTICE OP MEDICINE, Examiner, Nov. 15, 1874 we do not know of its equal.- Fa. Med. Monthly. \ Without doubt the best book of thekind published As a brief, condensed, .but comprehensive hand- j in the English language. — St. Louis Med. and Surg. • i Journ , Nov. 187-1. W: ATSON [THOMAS], M.D., ^c. LECTURES ON THE PRINCIPLES AND PRACTICE OF PHYSIC. Delivered at King's College, London. A new American, from the Fifth re- vised and enlarged English edition. Edited, with additions, and several hundred illustra- tions, by Henry Hartshorke, M.D., Professor of Hygiene in the University of Penn- sylvania. In two large and handsome 8vo. vols. Cloth, $9 00 ; leather, $11 00. {Lately Published.) It Is a subject for congratulation and for thank- , cate and important pathologicaland practical ques- ful lessthat Sir Thomas Watson, during a period of | tious, the results of his clear insight and his calm comparative leisure, after a long, laborious, and ! judgment are now recorded for the benefit of nutn- most tioaorableprofessional career, while retaining \ kind, in language which, for precision, vigor, and full possession of his high mental faculties, should classical elegance, has rarely been equalled, and have employed the opportunity to submit his Lee- never surpassed The revision has evidently been tures to a more thorough revisionthan was possible most carefully done, and the results appear in al- during the earlier and busier period of his life. ! most every page. — Brit. Med. Journ., Oct. 14, 1S71. Carefully passing in review some of the most intri- ; 16 Henry C. Lea's Publications — {Practice of Medicine). IDRJSTO WE {JOHN SVER), M.D., F.R.C.F., J^ Phynician and Joint Lecturer on Medicine., St. Thomases Hospital. A MANUAL OX THE PRACTICE OF MEDICINE. Edited, with Additions, by James II. IIuichinson, M.D., Physician to the Penna. Hospital. In one handsome octavo volume of over 1100 pages : cloth, $5 50; leather, $6 50. {Just Issued.) increHsed by the judicious noles of the Editor. — Oincinnnti Clinic, Jan. 7, 1677. Auyone who want.s a good, clear, condensed work upon PfHCtice, quite up with the most recent viewsin pathology, will tind this a most valuable work. The additions made by Dr. Hutchinson are appro))ilate This portly volume is a model of condensation. In a style at once clear, interesting, and concise, Dr. Bristowe passes in review every conceivable subject connected with the practice of medicine. Those practitioners who purchase few books will find this a moft opportune publication, because fco many top- _ ics not usually embraced in a work on practice are I and useful, andso well done that wewish there were adequately handled. The book is athoroughly good i more of them.— ^m, Fractilioner, Feb. 1877. one, and its usefulness to American readers has been i T^OODBURY {FRANK), M.D., Phyffician to the German Hospital, Philadelphia, late Chief Assist, to Med. Clinic, Jeff. College Hospital, etc. A HANDBOOK OF THE PRINCIPLES AND PRACTICE OF Medicine ; for the use of Students and Practitioners. Based upon Husband's Handbook of Practice. In one neat volume, royal 12mo. (Li Press.) flADERSHON [S. 0.). M.D. J- J- Senior Physician to and late Lecturer on the Principtes and Practice of Medicine at Guy's Hospital, etc. ON THE DISEASES OF THE ABDOMEN, COMPRISING THOSE of the Stomach, and other parts of the Alimentary Canal, (Esophagus, Caecum, Intes- tines, and Peritoneum. Second American, from the third enlarged and revised Eng- lish edition. With illustrations. In one handsome octavo volume of over 600 pages. Cloth, $3 50. {Noiv Heady.) This work has remained s^me time out of print, owing to the careful and conscientious revision which it has enjoyed at the hands of the author, and which hns nearly doubled its size since the appearance of the first edition. Yet there is no work accessible to the profession to take its place, as a careful, practical guide on a class of disea.se3, which form so large and important a portion of the duties of the physician, and for which the author's position has given him almost unequalled opportunities for observation and experience. We can do very little to add to the favorable re ception which has already been given by the medl cal press of the world to this well known treatise We commend to all practitioners a careful perusal of Dr. Hibershon's work. More especially, wedraw atteniion to the number of intestinal diseases re- corded in its pages, cases of extreme interest clini- cally and pathologically. This careful record shows that the work is no compilation, but a careful exposi- tion of the author's personal experience. — Canadian Med. and Surg. Journ., May, 1879. As a work of reference, as well as daily study, no work yet emanating from the med"cal press is worthy of more cireful consideration by the general practitioner than the above. With the careful re- vision given this edition. Dr. Habershon's work will sti 1 remain at tlie head of the list, and con tinue to be regarded as one of the best treatises on abdominal diseasas extant — South. Practitioner, June, 1879. There have been many laborers in this depart- ment of special pathology, and among them no one has dane better service than Dr. Habershon. The first -ditions were exhausted long since, and the author has revised the one now under consideration with great care and thoroughness. The chapters on constipation and intestinal obstruction are of high value, and are worth many times the cost of the book, wiiich, altogether, is a most excellent one. — St. Louis Vlin. Record, June, 1879. This valuable treatise on diseases of the stomach and al)dou.en has been out of print for several years, and is therefore not so well known to the profession as it deserves to be. It will be found a cyclopjedia of information, systematically arranged, on all dis- eases of the alimentary tract, from the mouth to the rectum A fair proportion of each chapter is devot- ed to symptoms, pathology, and therapeutics. The present edition is fuller than former ones in many particulars, a»d has been thoroughly revi.sed and amended by the author. Several new chapters have been added, bringing the work fully up to the times, and making it a volume of interest to the practitioner in every field of medicine and surgery. Perverted nutrition is in some form associated with all diseases we have to combat, and we need all the light that can be obtained on a subject so broad and general. Dr Habershon's work is one that every practiii ner should read and study for himself.— iV. Y. Mtd. Journ., April, 1879. J^OTHERGILL (J MILNER), M.D. Edm., M.R.G.P. Land., -*- Asst. Phys. to the West Lond Hosp. : Asst. Phys. to the City of Lond. Hosp.,etc. THE PRACTITIONER'S HANDBOOK OF TREATMENT; Or, the Principles of Therapeutics. In one very neat octavo volume of about 560 pages : cloth, $4 00. {Now Ready.) Our friends will find this a very readable book: and , he knew bow suggestive and helpful it would be to that it sheds light upon every theme it touches, causing i him.— .S^ Louis Mtd. and Surg. Journ , April, 1877. the practitioner to feel more certain of his diagnosis in I \Ve heartily commend his book to themedical student difficult cases. We confidently commend the work to «« an honest and intelligent guide through the mazes of our readers as one worthy of careful perusal. It lights therapeutics, and assure the practitioner who has grown the way over ot>scure and difficult passes in medical Nrray in the harness that he will derive pleasure and in- practice. The chapter on the circulation of the blood struction from its perusal Valuable sugge.-^tions and is the most exhaustive and instructive to be found. It material for thought abound throughout.- BoslonMed. is a book every practitioner needs, and would have, If i ^„^^ ^;.„^^ Journal, Mar. 8, 1877. ■DY THE SAME AUTHOR. THE ANTAGONISM OF THERAPEUTIC AGENTS, AND AVHAT IT TEACHES. Beinj; the Fothergillian Prize Essay for IS78. In one neat volume, royal 12mo. of 106 p.iges; cloth, $1 00. {Just Ready.) Henry C. Lea's Publications — (^Diseases of the Skin^ &c.), lY pEVNOLDS {J. RfTSSELL), M.D., -*■ •^ Prof, of the Principles and Practice of Medicine in Univ. College, London. A SYS TEM GF MRDTOINE. with Notes and Additions by Hkny IIabts- HORNK, M D., late Professor of Hygiene in the University of Pennfi. In three large and h.indsoine octavo volumes, containing about 3000 closely printed double columned pages, with numerous illustrations, {hi Press ) Reynolds's System of Medicine, recently completed, has acquired, since the first appearance of the first volume, the well-deserved reputation of being the work in which modern British medicine is presented in its fullest and most practical form. This could scarce be otherwise in view of the fact that it is the result of the collaboration of the leading minds of the profession, each subject being treated by some gentleman who is regarded as its highest authority — as for instance. Diseases of the Bladder by Sir Henrv Thompson, Malpositions of the Uterus by Graily Hewitt, Insanity by Henry Maudsley, Consumption by J. Hughes Bennet, Dis- eases of the Spine by Charles Bland Radcliffe, Pericarditis by Francis Sibson, Alcoholism by Francis E. Anstie, Renal Affections by William Roberts, Asthma by Hyde Salter, Cerebral Affections by tf Charlton Bastian, Gout and Rheumatism by Alfred Baring Gak- ROD, Constitutional Syphilis by Jonathan Hutchinson, Diseases of the Stomach by Wilson i-ox, Dise.ises of the Skin by Balmanno Squire, Affections of the Larynx by Morell Mac- > ENZiE, Diseases of the Rectum by Blizard Curling, Diabetes by Lauder Brunton, Intes- tinal Liseases by John Syer Buistowr, Catalepsy and Somnambulism by Thomas King Cham- bers, Apoplexy by J. Hughlings Jackson, Angina Pectoris by Professor Gairdner, Emphy- sema of the Lungs by Sir William Jenner, etc. etc. All the leading schools in Great Britain have contributed their best men in generous rivalry, to build up this monument of medical sci- ence. St. Bartholomew's, Guy's, St Thomns's, University College, St Mary's in London, while the Edinburgh, Glasgow, and Manchester schools are equally well represented, the Army Medical School at Netley, the military and naval services, and the public health boards. That a work conceived in such a,spirit, and carried out under such auspices should prove an indispensable treasury of facts and experience, suited to the daily wants of the practitioner, was inevitable, and the success which it has enjoyed in England, and the reputation which it has acquired on this side of the Atlantic, hnve sealed it with the approbation of the two pre-eminently practical nations. Its large size and high price having kept it beyond the reach of many practitioners in this country who desire to possess it, a demand has arisen for an edition at a price which shall ren- der it iicce.«sible to all. To meet this demand the pre-eent edition has been undertaken. The five volumes and five thousar d pages of the original will, by the use of a smaller type and double columns, be compressed into three volumes of about three thousand pages, clearly and hand- somely printed, and offered at a price which will render it one of the cheapest works ever pre- sented to the American profession. But not only will the American edition be more convenient and lower priced than the English ; it will also be better and more complete. Some years having elapsed since the appearance of a portion of the work, additions will be required to bring up the subjects to the existing condition of sciei\ce. Some diseases, al?!0, which are comparatively unimportant in England, require more elaborate treatment to adapt the articles devoted to them to the wants of the American physi- cian ; and there are points on which the received practice in this country differs from that adopted nbroad. The supplying of these deficiencies has been undertaken by Henry Harts - HORNE, M.D., late Professor of Hygiene in the University of Pennsylvnnia, who will endeavor to render the Avork fully up to the day, and as useful to the American physician as it has proved to be to his English brethren. The number of illustrations will also be largely increased, and no effort will be spared to render the typographical execution unexceptionable in every respect. The preparation of the work is now proceeding as rapidly as is compatible with its careful exe- cution, and its appearance may be expected at an early day. J^OX [TILBURY), M.D., F.R.C.P.,and T. C. FOX, B.A., M.R.G.S., Physician to the Department for Skin Diseases, University College Uospitol. EPITOME OF SKIN DISEASES. WITH FORMULAE. For Stu- dents and Practitioners. Second edition, thoroughly revised and greatly enlarged. In one very handsome 12mo. volume of 216 pages. Cloth, $1 38. {Just Ready.) The names of the authors are quite sufficient to i exceeds in size, and Furpdsses in use, its predeces- comrnsnd ttiis book, Dr Tilbury Fox being well \ sor. The work is certainly a valuable addition to known as occnpying a place in the front rank of j the '• handy volume" department of medical litera- dermatologists of the A&y.— Canadian .Journal of ture. — The Med. BuHeixn, May, ls7b Med. Soi , May, l!'78. p,^,, gtudents a better book was uwver devised. — The present edition of the Epitome considerably I Cincinnati Lancet and Ciinic, May, lb79. ILSON ( ERASM US), F. R. S. THE STUDENT'S BOOK OF CUTANEOUS MEDICINE aiidDis- BASES OF THE SKIN. In one very handsome royal 12mo. volume. $3 50. ILLIER [THOMAS), M.D., Physician to the Skin Department of University College Hospital, etc. HAND-BOOK OF SKIN DISEASES, for Students and Practitioners. Second Am. Ed. In one royal 12mo. vol. of 358 pp. With Illustrationf Cloth, $2 25. It is a concise, plain, practical treatise on the I dents ard practitioners. — Chicago Medical Ex- var ous diseases of the skin ; just such a work, aminer, Maj 1863. indeed, as was much needed, both by medical stu- W' H 18 Henry C. Lea's Publications — {Practice of Medicine). PINLAYSON {JAMES), M.D., Physician and Lecturer on Clinical Medinne in th'. Glasgow Western Infirmary, etc. CLINICAL DIAGNOSIS; A Handbook for StucUnits and Prac- titioners of Medicine. In one handsome 12mo. volume, of 546 pages, Avith 85 illustra- tions. Cloth, $2 63. {Just Ready.) The concurrence of gentlemen specially familiar with the several subjects being requisite to the satisfactory development of a plan so extensive, Dr. Finlayson hns secured the co-operation of Prof. Gairdner, who has contributed the chapter on the Physiognomy of Disease ; Prof. Wm. Stephenson that on Disorders of the Female Organs; Dr. Alex. Robertson that on Insanity; Prof. Samson Gemmell those on the Sphygmograph and Physical Diagnosis; and Dr. Joseph Coates those on the Fauces, Larynx, and Nares, and on the method of -peviorxaxwy;, post-mortem examinations. Other chapters have enjoyed the advantage of revision by gentlemen specially versed in their several subjects; and the volume is presented as thoroughly on a level with the most advanced condition of knowledge in a department which has made such rapid strides of advancement within the last few years. The book is aa excellent one, clear, coacisc, conve- nieut, practical. It is replete with the very kuow- ledge the student needs when he quits the lecture- room and the laboratory for the ward and sick-room, aud does not lack in iuformation that will meet the wants of experienced and older men.— Phila. Med. Times, Jan. 4, 1S79. The aim of the author is to teach a student and practitioner how to examine a case so as to use "all his knowledi/e'" in arriving at a diaguosT.s. All the various symptoms of the several systems are grouped together in sucii a manner as to mtke their relations to a final diagnosis clear and easy of apprehension. This work has been done by men of large experience and trained observation, who have been long recog- nized as authorities upon the subj. ess which they treat. There i.s a profusion of illustrations to illus- trate subjects under discussion. The application of electricity, and instruments of precision in diagnosis, is fully di.--cussed. This book i.s all good. We com- mend it to all students aud practitioners of medicine as a work worthy of a place in their libraries. — Ohio Med. Recorder, Dec. 1878. This is one of the really useful book.s. It is attrac- tive from preface to the final page, and ought to l)e given a place ou every otTico table, because it contains in a condensed form all that is valuable in semeiology and diagnostics to be found in bulkier volumes, and because in its arrangement aud complete index, it is unusually convenient for quick reference in any emergency ttiat may come upon the busy practitioner. —N. 0. Med. Journ., Jan. 1879. This is a most important work for students, and one that is dtstined to become rapidly popular. It is composed of contributions from various eminent sources bearing upon this subject. The real secret of succes.sful practice i.s the accurate diagnosis of disease. This manual teaches the student to arrange his investigation in such sy.stera as to enable him, with practice, to acquire this very desirable faculty. The division of the subject, as in this work, among the highest authorities living, is a good idea, and gives us in one compact form a series of monographs written by masters. — Nashville Journal of Med. and Surg., Jan. 1879. JJ^AMILTON {ALLAN MrLANE), M.D., Attending Physician at the Hospital for Epileptics and. Paralytica, BlacliwelVs Island, N. Y., and at the Out- Patients'' Department of the New York Ho.i2nial. NERVOUS DISEASES; THEIR DESCRIPTION AND TREATMENT. In one handsome octavo volume of 512 pages, with 53 illus.; cloth, $3 50. {Just Ready.) connected with the nervous system. We have no he.sitatiou in saying that reliance may be placed on Dr. Hamilton's conscientious performance of his sel!- assigued task, on his soundness of judgment, and freedom from empiricism. — Edinburgh Med. Journ., Oct. 1S78. This is unquestionably the best and mofet com plete text-book of nervous diseases that has yet ap- peared, and were interuaiioaal jealousy in scientific afi'airs at all possible, we might be excused f >v a feeling of chagrin that it should be of American parentage. This work, however, has been performed in New York and has been .so well performed that | f,.„„ ^ pj,,gf„^ examination of the whole no room is ^left for auytl>mg but ^corameudation. | ^ork.wecar justly .say that the author has not only "' ' '"" "' '■- •" clearly and fully treated of diagnosis and treatment, With great skill. Dr. Hamilton ha-* presented 'o h readers a succinct and lucid survey of all that is known of the pathology of the nervous sy.stem, viewed in the light of the most recent re-searche*. From the preliminary description of the methods of examination and study, and of the instruments of precision employed in the investigation of nervou^^ diseases, up till the final collection of foruiulie, tiie book is eminently practical. — Brain, London, Oct. 1S78. The author tells us in his preface that it has been his object to produce a concise, practical book, and we think he has been successful, considering the ex- tent of the subject which he has umlertakeu. In fact, it is more extensive than :iie title properly or accurately indicates, embracing- be.sides wh>it are u.sually regarded as nervous diseases — inflammatory aff"ections, both acute and chronic, hemorrhages and tumors of the cerebrum and cerebellum, medulla oblongata, spinal cord and nerves, with thrombosis and embolism of the arteries, sinuses, and veins. The reader may therefore expect information, more or less full and satisfactory, ou almost every point but. uulikH most works of this class, it is very com- prehensive in regard to etiology, and exposes the pathology of nervous diseases in the light of the very late-t experiments and discoveries. The drawings are excellent and well selected. After this careful revision, we can heartily recommend this work to stu'^ents and general practitioners in particular as being a full expo-ition of diseases of the nervous sy.-- tem, their pathology and treatment, to date.— iV. Y. Med. Record, Aug. 3, 1878. As stated in the preface, the author's object lias been to write a concise and practical book, for which there is certainly a place, and we think he has succeeded admirably in fulfilling his object. The u.^ual plan is adopted in the classification of the different disease^, the book not being greatly unlike Hammond's in this respect, although it is very noticeable throughout that the author's opin- ions vary widely from those of l)r Hammond. — Am. Sup p. O^atd. Journ. Great Britain and Ireland, July, 1S7S. QHARCOT {J. M.), Professorto the Facility of Med. Paris, Phya. to La Sa/p^tri^re, etc. LECTURES ON DISEASES OF THE NERVOUS SYSTEM. Trans- lated from the Second Edition by Gkoroe SroKRSON, M.D., M.Ch., Lecturer on Biology, etc., Cath. Univ. of Ireland. With illustrations {Puhli.^hing iti the Medical News and Library, commencing with the July No. 1878 See page 2 ) Henry C. Lea's Publications — (Diseases of the Chesty dec), 19 'DRO WN [LENNOX), F.R.G.S. Ed., Senior Surgeon tothe Central London Throat and Ear HoftpHal, etc., THE THROAT AND ITS D1SP]ASES. With one luinclrccl Typical Illustrations in colors, and fifty wood engravings, designed and executed by the author. In one very hanil^ome imperial octavo volume of 351pages ; cloth, $5 00. {Now Ready ) The author's rare artistic skill has been utilized in the iirocluction of one liinidred beautiful illuslra- lions ill colors, the very best of the kind we have se«n,aud which have been distributed in ten plales. Fifty woud engravings, designed and executed by the autuor, appear la the body of the work — these are unusually accurate. In conclusion, we recom- mend this beautiful volume as an acceptable addi- tion to the library of those engaged in the treatment of diseases of the throat. — N. Y. Med. Record, Nov. 9, 1S7S. CfEILER {CARL), M.D., ^ Lechirer an Laryngo.scupy at the Univ. of Penna , Chief of the Throat Dispensary at the Univ. Hospital, Phila., etc. HANDBOOK OF DIAGNOSIS AND TREATiMENT OF DISEASES OF THE THROAT AND NASAL CAVITIES. In one handsome royal 12mo. volume, of 156 pages, with 35 illustrations; cloth, $1. {Just Ready.) pLINT {AUSTIN), M.D., Professor of the Principles and Practice of Medicine in Bellevue Hospital Med. College, N. Y. PHTHISIS: ITS MORBID ANATOMY, ETIOLOGY, SYMPTOM- ATIC EVENTS AND COMPLICATIONS, FATALITY AND PROGNOSIS, TREAT- MENT, AND PHYSICAL DIAGNOSIS ; in a series of Clinical Studies. By Austin Flint, M.D. , Prof, of the Principles and Practice of Medicine in Bellevue HcspitafMed. College, New York. In one handsome octavo volume : $3 50. {Lately Issued.) This book contains an analysis, in the authoi-'s lucid I mend the book to the perusal of all interested in the piyle, of the notes which he has made in several bun- study of iliis disease. — Boston Med. and Surg. Journal, dred cases in hospital and private practice. We com- | Feb. 10, 1876. DY THE SAME AUTHOR. A MANUAL OF PERCUSSION AND AUSCULTATION; of the Physical Diagno.sis of Diseases of the Lungs and Heart, and of Thoracic Aneurism. In one handsome royal 12mo. volume: cloth, $1 75. {Just Issued.) JDF THE SAME AUTHOR. A PRACTICAL TREATISE ON THE DIAGNOSIS, PATHOLOGY, AND TREATMENT OF DISEASES OF THE HEART. Second revised and enlarged edition. In one octavo volume of 550 pages, with a plate, cloth, $4. Dr. Flint chose a difficult subject for his researches, ; aud clearest practical treatise on those subjects, and and has shown remarkable powers of observation \ ihould be in the hands of all practitioners aud stu- aud reflection, as well as greatindustry, in his treat- j ients. It is a credit to American medical literature. ment of it. His book must be considered the fullest | —Amer. Jotirn. of the Med. Sciences, July, 1860. JJY the SAME AUTHOR. A PRACTICAL TREATISE ON THE PHYSICAL EXPLORA- TION OF THE CHEST AND THE DIAGNOSIS OF DISEASES AFFECTING THE RESPIRATORY ORGANS. Second and revised edition. In one handsome octavo volume of 595 pages, cloth^$4 50. WILLIAMS'S PULMONARY CONSUMPTION; its Nature, Varieties, and Treatment. With an An- alysis of One Thousand Cases to exemplify its duration. In one neat octavo volume of about .SoO pages; cloth, $2 50. SLADE ON DIPHTHERIA; Its Nature and Treat- ment, with an account of the History of its Pre- valence in various Countries. Second and revised edition. In one neat roval 12mo. volume, cloth, $1 2.5. WALSHE ON THE DISEASES OF THE HEART AND GREAT VESSELS. Third American Edition. In 1 vol. Svo., 420 pp., cloth, $3 GO. LECTURES ON THE DISEASES OF THE STOMACH. With an Introduction on its .'Vaatomy and Physio- logy. By Wii.MAM Brinton, M.D., F.R.S From the second and enlarged Londonedition. With il- lustrations on wood. In one handsome octavo volume of about 300 pages: cloth, $."3 26. LA ROCHE ON PNEUMONIA. 1 vol. 8vo., cloth, of .500 pages. Price, $3 00. LINCOLN'S ELECTRO-THERAPEUTICS; a Concise Manual of Medical Electricity. In one very neat royal 12rao. volume, cloth, with illustrations, $1 50. CLINICAL OBSERVATIONS ON FUNCTIONAL NERVOUS DISORDERS. By C. Handfield JoNEd, M.D., Physiciau to St. Mary's Hospital, &c. Sec end American Edition. In one handsome octavo volumeof 318 pages.cloth, $3 25. FULLER ON DISEASES OF THE LUNGS AND AIR- PASSAGES. Their Pathology, Physical Diagnosis, Symptoms, and Treatment. From the second and revised English edition. In one handsome ocatvo volume of about 500 pages : cloth, $3 50. CHAMBERS'S MANUAL OF DIET AND REGIMEN IN HEALTH AND SICKNESS. la one handsome octavo volume. Cloth, ^2 75. CHAMBERS'S RESTORATIVE MEDICINE. An Har- veiau Annual Oration. With Two Sequels. In one very handsome vol. small 12mo., cloth, $1 00. PAVY'S TREATISE ON THE FUNCTION OF DI- GESTION ; its Disorders and their Treatment. From the second London edition. In one hand- some volume, small octavo, cloth, ^2. 00. PAVY'S TREATISE ON FOOD AND DIETETICS. Physiologically and Therapeutically Considered. In one handsome octavo volume of nearly 600 pages, cloth, if;! 75. S^IITH ON CONSUMPTION ; ITS EARLY AND RE- MEDIABLE STAGES. 1 vol. Svo. , pp. 2/54. $2 2.'^. BASHAM ON RENAL DISEASES: a Clinical Guide to their Diagnoais and Treatment. With Illustra- tions la one 12mo. vol. of 304 pages, cloth, *2 00. LECTURES ON THE STUDY OF FEVER. By A. HuDSox, M.D., M.R.I. A., Physician to the Meath Hospital. In one vol. Svo., cloth, *2 50. A TREATISE ON FEVER. By Robkrt D. Lyonp, K C C. In one octavo volume of 3b2 pages, cloth, *2 25. 20 Henry C. Lea's Publications — ( Venereal Diseases^ &c.), DUMSTEAD {FREEMAN J.), M.D., ■*-' ProfesHor of Venereal Diseases at the Col. of Phys. and Surg., New York, Ac. THE PATHOLOGY AND TREATMENT OF VENEREAL DIS- EASES. Including the results of recent investigations upon the subject. Fourth edition, revised and enlarged. In one large and handsome octavo volume ol over 700 pages. (Pre2)aring.) flULLERIER [A.], and J^UMSTEAD [FREEMAN J.), ^ Surgeon to the Ubpitaldu Midi. J~^ ProfsMsor of Venereal Dismses in the College of Physioians and Surgeons. N. ¥. AN ATLAS OF VENEREAL DISEASES. Translated and Edited by Frkeman J. BuMSTBAD. In one large imperial 4to. volume of 328 pages, double-columns, with 26 plates, containing about 160 figures, beautifully colored, many of them the size of life; strongly bound in cloth, $17 00 ; also, in five parte, stout wrappers, at $3 per part. Anticipating a very large sale for this work, it is offered at the very low price of Thrkk Dol- lars a Part, thus placing it within the reach of all who are interested in this department of practice. Gentlemen desiring early impressions of the plates would do well to order it without delay. A specimen of the plates and text sent free by mail, on receipt of 26 cents. of illustrations of the venereal diseases. There is, however, an additional interest and value pohBesprd We wish for once that our province was not re- strict d to methods of treatment, that we might say eomebing of the exquisite colojed plates in this volume. -London Practitioner, May, 1869. Other writers besides M. CuUerier have given use good g.ccount of the disease." of which he treats, bui no one has furnished us with such a complete seriei by the volume before oi-; for it is an Ajnericau reprint and translation of M Cullerier's work, with inc • dental remarks by one of the most eminent Ameri- can syphilographers, Mr. Bumstead. — BritandFot . Medico-Chir. Review, July, 1869. 'EE {HENRY), ■' Prof, of Surgery at the Royal College of Surgeons of England, etc. LECTURES ON SYPHILIS AND ON SOME FORMS OF LOCAL DISEASE AFFECTING PRINCIPALLY THE OBGANS OF GENERATION. In one handsome octavo volume: cloth; $2 25. {Lately Ptihlished.) TJILL {BERKELEY), -^-*- Surgeon to the Lock Hospital, London. ON SYPHILIS AND LOCAL CONTAGIOUS DISORDERS. In one handsome octavo volume ; cloth, $3 25. ^EST ( CHARLES), M.D., Physician to the Hospital for Sick Children, London, &c. LECTURES ON THE DISEASES OF INFANCY AND CHILD- HOOD. Fifth American from the sixth revised and enlarged English edition. In one large and handsome octavo volume of 678 pages. Cloth, $4 50 ; leather, $5 50. {Lately Issued ) The continued demand for this work on both sides of the Atlantic, and its translation into German, French, Italian, Danish, Dutch, and Russian, show that it fills satisfactorily a want extennvely felt by the profession. There is probably no man living who can speak with the authority derived from a more extended experience than Dr. We8t,#nd his work now presents the re.sults of nearly 2000 recorded cases, and 600 post-mortem examinations selected from among nearly 40,000 jases which have passed under his care. In the prepar.ition of the pre- sent edition he has omitted much that appeared of minor importance, in order to find room for the introduction of additional aaatter, and the volume, while thoroughly revised, is therefore not increased materially in size. Jf all the English writers on the diseases of chil- j highest living authorities in the difficult department dr^a, there is. no one so entirely satisfactory to us | of medical science Jn which he is most widely as Dr. West. For years we have held his opinion I known.- Boston Med. and Surg. Journal. as JQdicial, and have regarded him as one of the | JDY THE SAME AUTHOR. (Lately Issued.) ON SOME DISORDERS OF THE NERVOUS SYSTEM IN CHILD- HOOD; being the Lumleian Lectures delivered at the Royal College of Physicians of London, in March, 1871. In one volume small 12mo., cloth, $1 00. ^F THE SA^fE AUTHOR. LECTURES ON THE DISEASES OF WOMEN. Third American, from the Third London edition. In one neat octavo volume of about 650 pages, clotl, $3 75; leather, $4 75. CONDTE'S PRACTICAL TREATISE ON THE DIS- ' SMITH'S PRACTICAL TRE.\TISE ON THE WAST- EASES OF CHILDREN. Sixth edition, revised and augmented. In one large octavo volume of nearly 8*^0 cio.sely-printed pages, cloth, $5 2.0 ; leather, $^ 2o. IN« DISEASES OF INFANCY AND CHILDHOOD. Second American, from the second revised and enlaigf^d Englirili edition. In one bandiiiome octa- vo volume, cloth $2 50. Henry C. Lea's Fubltcations — (Diseases of Child^-en). 21 (^MITH{J. LEWIS), M.D., Clinical Professor of Diseases of Children in the Bellevue Hospital Med. College, N T. A COMPLETE PRACTICAL TREATISE ON THE DISEASES OF CHILDREN. Fourth Edition, revised and enlarged. In one handsome octavo volume of about 750 pages, with illustrations. Cloth, $4 .^0 ; leather, $5 50, (]^ow Reridy.) The very marked favor with which this work has been received wherever the English lan- guage is spoken, has stimulated the author, in the preparation of the Fourth Edition, to spare no pains in the endeavor to render it worthy in every respect of a continuance of professional confidence. Many portions of the volume have been rewritten, and much new matter intro- duced, but by an earnest effort at condensation, the size of the work has not been materially ncreased. In the period which has elapsed since the third edition of the work, so extensive have been the ad- vances that whole chapters required to be rewritten, and hardly a page could pass without some material correction or addition. This labor has occupied the writer closely, and he has performed it conscien- tiously, so that the book may he considered a faith- ful portraiture of an exceptionally wide clinical experience in infantile diseases, corrected by a care- ful study of the recent literature of the subject.— Med. and Surg. Reporter, April 5, 1879. It is scarcely necessary for us to say the work be" fore us is a standard work upon diseases of children, and that no work has a higher standing than it upon those atfections. In consequence of its thorough re- vision, the work has been made of more value than ever, and may be regarded as fully abreast of the times. We cordially commend it to stnd'^nts and physicians. There is no better work in the language on diseases of children.— Ci7icmna« Med. News, March, 1879. Ihe author has evidently determined that It shall not lose ground in the esteem of the profession for want of the latest knowledge on that important department of medicine. He has accirdingly in- corporated in the present edition the useful and practical remits of the latest study and experience, brth American and foreign, especially those beaiirg on therapeutics. Altogether the book has been greatly improved, while it has not been greatly increased in size. — H'ew York Mtdlcal Journal, June, 1879. This excellent work is so well known that an ftx'ended notice at this time would be supertlnous. The author h^s taVen advantage of the demand for another new erit on to revise in a most carelul manner the entire book ; and the numerons correc- tions and additions evince a determination on his part to keep fully abreast with the rapid progress that Is being made in the knowledge and treatment of children's diseases. By the adoption of a srme- what closer type, an increase in size of only thirty pages has been necestitated by the new subject matter introduced.— jBos^oh Med. and Surg. Jour., May 29. 1879. Probably no other work ever published in this country upon a medical subject has reached such a heighth of populirity as has this well-known trea- tise. As a text and reference-book it is preemi- nently the authority upon diseases of children. It stands deservedly higher in the estimation of the profession than any other work upon the same ^wh- jeci.— Nashville Journ. of Med. and Surg., May, 1879. The author of this work has acquired an immense experience as physician to three of the large char- ities of New York in which children are treated. These asylums afford unsurpassed opportunities for observing the effects of different pluns of treatment, and the results as embodied in this volume may be accepted with faith, and should be in the possession of all practitioners now, in vipw of the approacbing season when the diseases of children always increase. —Nat. Med. Review, April, 1879. S WAYNE {JOSEPH GRIFFITHS), M.D., Physician-Accoucheur to the British General Hospital, Ac. OBSTETRIC APHORISMS FOR THE USE OF STUDENTS COM- MENCING MIDWIFERY PRACTICE Second American, from the Fifth and Revised London Edition, with Additions by E. R. Hutchins, M.D. With Illustrations. In one neat 12mo. volume. Cloth, $1 25. {Lately Issued.) *** See p. 4 of this Catalogue for the terms on which this work is offered as a premium to subscribers to the " American Journal of the Medical Sciences." CHURCHILL ON THE PUERPERAL FEVER AND OTHER DISEASES PECULIAR TO WOMEN. 1vol. Svo. , pp. -l.^O, cloth . $2 50. DEWEEh'R TREATISE ON THE DISEASES OF FE- MALES. With illustrations. Eleventh Edition, with the Author's lastimprovementsand correc- tions. In one octavo volume of 536 pages, with plates, cloth. $3 00. MEIGS ON THE NATURE, SIGNS. AND TREAT- MENT OF CHILDBED FEVER. 1 vol. Svo., pp. .365. cloth. $2 CO. ASHWELL'b PRACTICAL TREATISE ON THE DIS- EASES PECULIAR TO WOMEN. Third American, from the Third and revised London edition. 1 vol. Svo. , pp. 528, cloth. $3 50. J^ODQE [HUGH L.), M.D., Emeritus Professor of Obstetrics, Ac, in the University of Pennsylvania. ON DISEASES PECULIAR TO WOMEN ; including Displacements of the Uterus. With original illustrations. Second edition, revised and enlarged. In one beautifully printed octavo volume of 531 pages, cloth, $4 50. Professor Hodge's work is truly an original one I contribution tothe study ofwomen'ediseases.itiprf from beginning to end, consequently no one can pe- great value, and is abundantly able to stand on its raseits pageewithout learning something new. Af-a I own merits. — N. Y. Medical Record, Sept. 15, ICfci. HURCHILL (FLEETWOOD), M.D., M.R.I.A. ON THE THEORY AND PRACTICE OF MIDWIFERY. A new American from the fourth revised and enlarged London edition. With notes and additior s by D. Francis Condib, M.D., authoY of a " Practical Treatise on the Diseases of Chil- dren," Ac. With one hundred and ninety four illustrations. In one very handsome octavo volume of nearly 700 large pages. Cloth, $4 00 ; leather, $5 00. O' MONTGOMERY'S EXPOSITION OF THE SIGNS RiOBY'b SYSTEM OF MIDWIFERY. \Vith notes 4.ND SYMPTOMS OF PREGNANCY. With two and Additional illastrations. Second American exquisitecoloredplates. and numeronswood cuts I "^ition. One ▼olume octavo, cloth, 422 pages, In 1 vol.8vo.,ofnearly600pp.,clotb,$3 76. I $2 50. 22 Henry C. Lea's Publications — (Diseases of Women). fTHOMAS {T.GAILLARD),M.D., *• Proftsfior of Obstetrics, Ac, in the College, of Physicians and Surgeons, N. T., Ac A PRACTICAL TREATISE ON THE DISEASES OF WOMEN. Fourth edition, enlarged and thoroughly revised. In one large and handsome octavo volume of 800 pages, with 191 illustrations. Cloth, $5 00; leather, $6 00. (Just Issued.) The author has taken advantage of the opportunity afforded by the call for another edition of this work to render it worthy a continuance of the very remarkable favor with which it has been received. Every portion has been subjected to a conscientious revision, and no labor has been spared to make it a complete treatise on the most advanced condition of its important subject. A work which has reached a fourth edition, and isclassical without beingpedauticfiill in ihedetails thut. too. in tlie short space of five years, has achieved of anatoiny and pathology, without ponderous a reputation which placef? it almost beyond the rench : translation of pagesof German literature, describes of criticism, and the favorable opinions which we have i distinctly the details and difficulties of each opera- tion, without wearying and useless minutise, and is a r..'ady expressed of the former editions seem to re- quire that we should do little more than announce this new issue. We cannot refrain from sayinp; that, as a practical work, this is second to none in the Eng- j lish, or. indeed, in any other lanfjuage. The arrange- 1 ment of the contents, the admirably clear manner in | which the subject of the ditferential diagnosis of several of the diseases is handled, leave nothing to be ' desired by the practitioner who wants a thoroughly clinical work, one to which he can refer iu difficult cases of doubtful diagnosis with the certainty of gain- ing light and instruction. Dr. Thomas is a man with a very clear liend and decided views, and there seems to be nothing which he so much dislikes as hazy notions 1 of diagnosis and blind routine and unreasonable thera- \ peutics. The student who will thoroughly study this! b )ok and test its principles by clinical observation, will ' certainly not be guilty of these faults.— ZowdonZarace^ I Feb. 1.3, 187.5. ' ! Reluctantly we are obliged to close this unsatis- [ factory notice of so excellent a work, and in conclu- sion would remark that, as a teacher ofgyna;cology. in all respects a work worthy of confidence, justify- ing the high regard in which its distinguished au- thor is held by the profession.— .4m. Supplement, Ohstet. Journ., Oct. 1874. Professor Thomas fairly took the Profession of the United States by storm when his book first made its appearance early in 1S6S. Its reception was simply enthusiastic, notwithstanding a few adverse criti- cisms from our transatlantic brethren, the first large edition was rapidly exhausted, and in six months a second one was issued, and in two years athird one was announced and published, and we are now pro- raised the fourth. The popularity of this work was not ephemeral, and itssuccess was unprecedented in the annalsof American medical literature. Six years is a long period in medical scientific research, but Thomas's work on " Diseases of Women" is still the leading native production of the United States. The order, .'the matter, the absence of theoretical disput a- tiveness, the fairness ofstatement, and the elegance both <\\A'irt\r-A„^ r.iin;«ai P,.^«- T^i^^wo^iT" ^ ■ "i" [ of diction, preserved throughout the entire range of author he certainly has met with unusual and mer- 1 overestimate bis powers when he conceived the idea ited sacc^HB.-Am Journ. of Obstetrics, Nov 1874 i ^^'^ «^?'^"ted the work of producing a new treatise ■'• '^^ ^°'*- I upon diseases of women.— Prof. Pallen, in ioMj*. L ills volume of Prof. Thomas in its revised form viUe Med. Journal, Sept. 1874. J?ARNES (ROBERT), M.D., F.R.G.P., •*-^ Ob.stetric Physician to St. Thomas's Hospital, Ac. A CLINICAL EXPOSITION OF THE MEDICAL AND SURGI- CAL diseases OF WOMEN. Second American, from the Second Enlarged and Revised English Edition. In one handsome octavo volume, of 784 pages, with 181 illustrations. Cloth, f 4 50 ; leather, $5 50. {Just Ready.) The call for a new edition of Dr. Barnes's work on the Diseases of Females has encouraged the author to make it even more worthy of the favor of the profession than before. By a renr- rangement and ciireful pruning space has bpen found for a new chapter on the Gyngecologieal Relations of the Bladder and Bowel Disorders, without increasing the size of the book, while many new illustrations have been introduced where experience has shown them to be needed. It is therefore hoped that the volume will be found to reflect thoroughly and accurately the present condition of gynecological science. Dr Barnes stands at the head of his profession in the work is a valuable one, and should be largely he^old^coiintry, and it requires but scant scrutiny consulted by the profession.— /Iw. Svpp. Obstetrical Journ. Gt. B7'itain and Ireland, Ocl.lS7S. of his hook to show that it has been sketched by a m ister. It is plain, practical common sense ; shows very deep research without being pedanitic; is emi- nently calculated to inspire enthusiasm without in- culcating rahhness; points out the dangers to be avoided as well as the success to be achieved in the various operations connected with th's branch of medicine; and will do much to smooth the rugged path of the young gynecologist and relieve the per- j plexity of the man of mature veavs. — Canadian \ Journ. of Med. Science, Nov. 1878. We pity the doctor who, having any consider- able practice in diseases of women, has no copy of have been made since the appearance of tlieVirst edi ' Barnes ' for daily consultation and instruction. It tion. The American references are, for an English is at once a book of great learning, research, and work, especially full and appreciative, and we can individual experience, and at the same time emi- I cordially recommend the volume to American read- nently practical. That it has been appreciated by ' ern.— Journ. of Nervous and Mental Disease, Oct, the profession, both in Great Britain and in this ' 1878. This second edition of Dr. Barnes's great work comes to us containing many additions and improve- ments which bring it up to date iu every feature. The excellences of the work are too well known to require onumeration, and we hazard the prophecy that they will for many years maintain its high po- No other gynajcological work holds a higher posi- tion, having become an authority, everywhere in diseases of women. The work has been brought fully abreast of present knowledge. Every practi- tioner of medicine should have it upon the shelves of his library, and the student will find it a superior text-hook.— Cincinnati Med. News, Oct. 1S7S. This second revised edition, of course, deserves all the commendation given to its predecessor, with the additional one that it appears to include all or nearly all the additions to our knowledge of its subject that country, is shown by the second edition following so soon upon the first.— ^m. Practitioner, Nov. 1S7S. ' Dr. Barnes's work is one of a practical character, largely illustrated from cases in his own experience, bat by no means confined to such, as will be learned from the fact that he quotes from no lef^s than 628 sition as a standard text-book anis, and generally for phi- losophical deduction and the equally important quality of patient, honest, coniinued work. For the work a.s a whole, we have only praise. It deserves and will receive the careful study of all who det^ire to keep on a level with the prognss of Gynecology. It embodies a larg.n- amount of carefully analyzed personal experience in a unique field for observa- tion than any volume on Diseases of Women which has yet been published. Its great merit cou.'-ists in this— coining as it does from a thoroughly honest, competent, and able specialist, who became a spe- cialist only after an (xcellent training and experi- ence as a general hospital physician and surgeon. The book is not one to be hastily glanced over, but will secure the critical stu-ly of Gynajcologists. Not only its style, which is individual and somewhat peculiar, but the new facts which it brings out, its original suggestions, its numerous and important statistical tables, and, in some instances, its unex- pected deductions, will compel attention, and will form the basis for a great deal of Gy aiccological study and literature in the future. All who make themselves familiar with the contents of this vol- ume, will feel assured that Dr. Emmet has well earned and well deserved the reputation which he has already won, a,s one of tte great Gynajcologists of the pres9nt age. — Tke Am. Journ. of Obstetrics, April, 1S79, We have examined this book with something more than ordinary care, and now lay it aside captivated by our impressions of it. From first to last, each page grows in interest, and one is struck with the practical tone of all that is said. It is indeed the gyna3cological work for the practitioner. Its equal is not yet published, or at least we have not seen it. We cannot send this notice forward without reiter- atirg that, in our estimation, Emmet's Principles and Practice of Gynajcology is undoubtedly thebest book for the student, as well as the general practi- tioner, which is at present published.— Fa. Med. Monthly, May, 1879. The advent of this important work has for some time been anxiously expected hy all who are inter- ested in the subject of gynecology, both here and abroad. The clinics held at the Woman's Hospital, and the minor writings referred to have acquired for Dr. Emmet a reputation for skill as an operator, and experience in the special branch to which he has exclusively confined his attention, which is probably unrivalled by any one on this continent. The anticipations which have been awakened re- garding the character of this extended treatise, are not likely to be disappointed, if one may judge from the very cursory review we have made of its con- tents.— New Remedies, May, 1S79. Few have had the rare opportunities of Dr. Em- met, and none have better improved that which was at their disposal. Sure are we that any practi- tioner of medicine, specialist, or otherwisf , who will read carefully this volume, will find that he pos- sesses a clearer insight into a thousand problems that have hitherto perplexed him. It is one of the best original works on the diseases of women pub- lished in this or any other land. We heartily com- mend it to the careful study of every medical man. —Detroit Lancet, May, 1S79. We are satisfied that whoever reads the book care- fully will agree with us that it is the best work on gynaecology that has ever been written. This is high prai^e, but we have no hesitation iu giving it. —St. Louis Can. Record, May, 1£79. riHADWICK [JAMES E.), A.M., M.D. A MANUAL OF THE DISEASES PECULIAR TO WOMEN. In one neat volume, royal 12mo , with illustrations. (Preparing.) America has contributed so largely to the advances which have made the treatment of Dis- eases of Women a distinctive department of medical science, that the student Avill naturally turn to American Books for the latest and most trustworthy instruction on the subject in its most modern aspect. Yet there has thus far been no attempt in this country to produce a handy manual, presenting in a condensed and convenient form the information requisite for the learner or for the general practitioner. This want it has been the effort of Dr. Chadwick to supply, and the special attention which he has devoted to the subject is a guarantee of the value of his labors. A distinguishing feature of the work will be a number of diagrammatic illustrations, facilitating greatly the comprehension of the text. TUI^CKEL [F.), ' ' Professor and Director of the Gyncecologieal Clinic in the University of Rostoclt. A COMPLETE TREATISE ON THE PATHOLOGY AND TREAT- MENT OF CHILDBED, for Students and Practitioners. Translated, with the consent of the author, from the Second German Edition, by Jaxfes Rk.\d Cii.vdwick, M.D. In one octavo volume. Cloth, $4 00, {Lately Issued.) 24 Henry C. Lea's Publications— (il/ic72i;i/(?7'f/). JpLAYFAIR ( W. S.), M.D., F.R.C.P., Professor of Obstetric Medicine in King's College, etc. etc. A TREATISE ON THE SCIENCE AND PRACTICE OF MIDWIFERY. Second American, from the Second and Revised English Edition. Edited, with Addi- tions, by RoBKUT P. Harhis, M.D. In one handsome octavo volume of G39 pages, with 182 illustrations. Cloth, §4 00 ; Leather, $5.00. {Just Ready ) In reprinting this work from the second London edition, the position which it has assumed in this country as an authoritative text-book seemed to call for such additions as would render it more completely suited to the wants of the American student. A careful scrutiny on the part of the editor has .«hown that but little was required for this purpose ; the work, though condensed, being very complete and accurate. With the exception of numerous short foot-notes, therefore, his additions have been confined to points in which the experience and practice of American obstetricians differ from those of England, and to one or two matters of recent interest. These are chiefly the Cassarean Section ; the varieties of forceps, and their use in the dorsal decubitus; dystocia from tetanoid uterine constriction; and the intra-venous injection of milk, as a substi- tute for the transfusion of blood. The position which this work has «o quickly taken ia this country as an aathoriiative text-book renders any exteudeJ con-idtration of it.-* {Ian and scope unnecessary. Its merits, which are many, have al- ready found their way to the appreciation of students and practitioners alike in the leug'h and breadth of the land.— .(4m. fiupj). Obdet. Juurn. of Qt. Britain and Ireland, Oct.lSTS. This excellent text-book has been submitted to a thorough and careful revision, and will be found fully up to the times in every department. The notes by the American editor enhance the value of the work for the Americitn student. Those on the use of forceps are particuUrly gjod, and constitute by themselves a valuable chapter. — N. Y. Med. Journ , Nov. 1S78. The bast work on the subject ever published in the English language It is written in a clear, pleasant style, without that verbosity which characterizes some modern and highly pretentiou.s works. The au- thor is quite up with the times, both in practice and theory. It is the best text-book we have for students, a nd sufficiently full of detail to supply all the wants of the practitioner. We would gladly see it in the hands of all who practise midwifery. — Canadian Journ. of Med. Set, Nov. 1S7S. Probably this is the very best and most useful manual of midwifery now available to the profes- sion. Itis written in lucid, scholarly English, which some of our els-Atlantic writers would do well to imitate. There has been no attempt to swell the magnitude of the work by fine writing, or by lengthy discussions ofobs^cure points of which no trustworthy solution has yet been reached ; on the contrary, the tendency is throughout obviously towards simplic- ity. The chapter upon the Mechanism of Labor (which ouglit to he the crowning chapter in a trea- tise on obstetrics) is remarkably clear and good, and is divested of those features which in almost every other work we know lets only darkness instead of light in upon the subject. — N. C. Med. Journ., Oct. 1878. T J^AElVES (FANCOUKT), M.D., -»-' Physician to the General Lying-in Hospital, London. A MANUAL OF MIDWIFERY FOR MIDWIVES. With numerous illustrations. In one neat royal 12mo. volume, {ht Press.) JTANNER {THOMAS H.), M.D. ON THE SIGNS AND DISEASES OF PREGNANCY. First American from the Second and Enlarged English Edition. With four colored plates and illustra- tions on wood. In one handsome octavo volume of about 500 pages, cloth, $4 25. HE OBSTETRICAL JOURNAL. [Free of postage for 1819.) THE OBSTETRICAL JOURNAL of Great Britain and Ireland; -Including Midwifery, and the Diseases os* Women and Infants. With an American Supplement, edited by J. V. Ingham, M.D. A monthly of about 96 octavo pages, very handsomely printed. Subscription, Five Dollars per annum. Single Numbers, 50 cents each. Commencing with April, 1873, the ObstetricalJournal consists of Original Papersby Brit- ish and Foreign Contributors ; Transactions of the Obstetrical Societies in England and abroad. Reports of Hospital Practice; Reviews and Bibliographical Notices; Articles and Notes, Edito.'ial, Historical, Forensic, and Miscellaneous; Selections from Journtils; Cor- respondence, Ac Collecting together the vast amount of material daily accumulating in this important and rapidly improving department of medical science, the value of the infor- mation which it presents to the subscriber may be estimated from the character of the gen- tlemen who have already promised their support, including such names as those of Drs. At- THILL, AVKLING, RoBERT B AUNES, J. HeNRY BeNNET, NATII AN BoZEMAN, ThOM AS Ch AM BERS, Fleetwood Churchill. Charles Clay, John Clav, Matthews Duncan, Arthur Farre, Robert Greendalgh, Graily Hewitt, Braxton Hicks, Alfred Meadows, W. Leisu- MAN, Alex. Simpson, Hevwood Smith, Tyler Smith, Edward J. Tilt, Lawson Tait, Spencer Wells, Ac. Ac. ; in short, the representative men of British Obstetrics and Gynes- cology. In order to render the Obstetrical Journal fully adequate to the wants of the Ameri- can profession, each number contains a Supplement devoted to the advances made in Obstet- rics and Gynaecology on this side of the Atlantic. This portion of the Journal is under the editorial charge of Dr J. V. Ingham, to whom editorial communications, exchanges, books for re/iew, Ac, may be addressed, to the care of the publisher. ♦AMSBOTHAM [FRANCIS H), M.D. ^ THE PRINCIPLES AND PRACTICE OF OBSTETRIC MEDJ- CINE AND SUEQERY, in reference to the Process of Parturition. A new and enlarged edition, thoroughly revised by the author. With additions by W. V. Keating, M. D., Professor of Obstetrics, Ac, iYi the Jefferson Medical College, Philadelphia. In one hiree and handsome imperial octavo volume of 650 pages, strongly bound in leather, with rai.«ed bands ; with sixty-four beautiful plates, and numerous wood-cuts in the text, containing in all nearly 200 large and beautiful figures. $7 00. (^TUISON [LEWIS A.), A.M., M.D., '^ Surgeon to the Presbyterian Hospital. A MANUAL OF OPERATIVE SURGERY. In one very handsome royal 12mo. volume of about 500 pages, with 332 illustrations ; cloth, $2 60. {Now Ready ) Tbe work before us is a well printed, profusely illustrated manual of over four hundred and seventy pages. The novice, by a perusal of the work, will gain a good idea of the general domain of oparative surgery, while the practical surgeon has presented to him within a very concise and intelligible form the latest aud most approved selections of operative procedure. Thepreci«ion atd conciseness with which the different operations are described enable the author to compress an immense amount of practical information in a very small compass. — N. Y. Medical Record, Aug. 3, 1878. This volume ie devoted entirely to operative sur- gery, and is iuteuded to familiarize the student with the details of operations and the differeut modes of i performing them. The work is handsomely illnsr trated, and the defcriptions are clear and well drawn. It is a clever and useful volume; every student should possess one. The preparation of this work does away with the necessity of pondering over larger works on surgery for descriptions of opera- liouH, as it presents in a nut-shell just what is wanted by the surgeon without an elaborate search to find it.— Md. Med Journal, Aug. 1878. The author's conciseness and the repleteness of the work with valuable illustrations entitle it to be classed with the text-books for students of operative surgery, and as one of reference to the prKCtitioner, Cincinnati Lancet and Clinic, July 27, 1S7S. SKET'S OPERATIVB SURGERY. In 1 vol. 8vo. cl.,of660pagaB; withabout 100 wood-cuts. $3 25 COOPER'S LECTURES ON THE PRINCIPLES AND PlACTICB OF SUBGKBT. In 1 vol. 8vo. cl'h, 760 p. $2. GIBSON'S INSTITUTES AND PRACTICE OF 8UR- aKRT. Eighth edit'n, improved and altered. With thirty-four plates. In two handsome oc*,avo vol- umes, about 1000 pp., leather, raised hand?. ^P 50. THE PRINCIPLES AND PRACTICE OF SURGERY. By William PiRRiK,F.R S.E., Profe^'r of Surgery ia the University of Aberdeen. Edited by John Neill, M.D., Professor of Surgery in tbe Penna. Medical College, Surg'n to the Pennsylvania Hos- pital, &c. In one very handsome octavo vol. of 780 pages, with 316 illustrations, cloth, $3 7,5. MILLER'S PRINCIPLES OF SURGERY. Fourth Ame- rican, from the Third Edinburgh Edition. In one large 8vo. vol. of 700 pages, with 340 illustrationp, cloth, $3 75. MILLER'S PRACTICE OF SURGERY. Fourth Ame- rican, from the last Edinburgh Edition. lievised by the American editor. In one large 8vo. vol. of nearly 700 pages, with 364 illustrations: cloth, $3 75 26 Henry C. Lea's Publications — {Surgery). fyROSS {SAMUEL D.), M.D„ ^-^ Professor of Surgery in the Jefferson Medical College of Philadelphia. SYSTEM OF SURGERY: Pathological, Diagnostic, Thernpeutic, and Operative. Illustrated by upwards of Fourteen Hundred Engravings. Fifth edition carefully revised, and improved. In two large and beautifully printed imperial octavo vol- umes of about 2300 pp., strongly bound in leather, with raised bands, $15. (Just Iss^ied.) The continued favor, shown by the exhaustion of successive large editions of this great work, proves that it has successfully supplied a want felt by American practitioners and students. In th« present revision no pains have been spared by the author to bring it in every respect fully up t( the day. To effect this a large part of the work has been rewritten, and the whole en- arged bj aearly one-fourth, notwithstanding which the price has been kept at its former very moderatf rate. By the use of a close, though very legible type, an unusually large amount of matter is condensed in its pages, the two volumes containing as much as four or five ordinary octavos This, combined with the most careful mechanical execution, and its very durable bind ing renderf, it one of the cheapest works accessible to the profession. Every subject properly belonging to the iomain of surgery is treated in detail, so that the student who possesses this ■work mayAe said to have in it a surgical library. We h#ve m)\v brought ourlask to a conclusion, and have setdom read a work with the practical value of which we have been moreimpressed. Every chapter is 80 concisely put together, that the busy practitioner, when in difficulty, can at once find the infoimation he requires. Ills work, on the contrary, i.s cosmopolitan, the surgery of the world beinti fully represented in it. The work, in fact, is so historically unprejudiced, and so eminentlypractical,that it is almost a false compli- ment to say tJiatwe believe it to be destined to occupy a foremost place as a work of reference, while a system of surgery like the present system of surgery is the practice of surgeons. The printing and binding of the work is unexceptionable; indeed, it contrasts, in the latter respect, remarkably with Ensrlish medical and surgical cloth-bound publications, which are generally so wretchedly stitched as to require re-binding before they are any time in use. — IJub. Journ. of Med. Sci., March, 1874. Dr. Gross's Surgery, a great work, has become still greater, both in size and merit, in its most recent form. The difference in actual number of pages ia not more than 1.30, but. the size of the page having been in- crea*ed to what we believe is technically termed ••ele- phant," there has been roomforconsiderableadditions, which, together with the alterations, are improve- ments.— Land. Lancei, Nov. 16, 1872. It combines, as perfectly as possible, the qualities of a text-book and work of reference. We think this last elition of Gross's "Surgery," will confirm his title of •' Primus intn- Pares." it is learned, scholar-like, me- thodical, precise, and exhaustive. We scarcely think any living man could write so complete and faultless a treatise, or comprehend more solid, instructive matter in the given number of pages. The labor must have been immense, and the work gives evidence of great powers of mind, and the highest order of intellectual di.-cipline and methodical disposition, and arrangement of acquired knowledge and personal experience. — N.Y. Med. Journ., Feb. 1873. As a whole, we regard the work as the representative "Sy.^tem of Surgery" in the Knglish language. — St. Louis Medical and Surg. Journ., Oct. 1872, The two magnificent volumes before us afford a very complete view of the surgical knowledge of the day. Some years ago we had the pleasure of presenting the first edition of Gross's Surgery to the profession as a work of unrivalled excellence; and now we have the result of years of experience, labor,and study, all con- densed upon the great work before us. And to students or practitioners desirous of enriching theirlibrary with a treasure of reference, we can simply commend the purchase of these two volumes of immense research — Qincinnati Lancet and Observer, Sept. 1872. A complete system of surgery — not a mere text-book of operalion.'?. but a. scientific account of surgical theory and itracticein all its dHpurtments. — Brit, and For. M'd C/iiV.i?«w., Jan. 1873. B Y THE SAME AUTHOR. A PRACTICAL TREATISE ON THE DISEASES, INJURIES, and Malformations of the Urinary Bladder, the Prostate Grland, and the Urethra. Third Edition, thoroughly Revised and Condensed, by Samuel W. Gross, M.D., Surgeon to the Philadelphia Hospital. In one handsome octavo volume of 574 pages, with 170 illus- trations: cloth, $4 50. {Just Issiied.) For reference andgeneral information, the physician leases of the urinary organs. — Atlanta Med . Journ.,Oc\. or surgeon can find no work that meets their necessities j 1876. more thoroughly than this, a revi.-ed editioii of an ex- ^ jg ^j^i^ pleasure we now again take up this old cellent treatise, and no medical library should be with- 1 ^^^k in a decidedly new dress. Indeed, it must be re- out it. Replete with handsome illustrations and good j garded as a new book in very many of its parts. The ideas, it has the unusual advantage ot being easily chapters on "Dlsea-^es of the Bladder," "Prostate compreheuded,by the reasonableand practical manner Ijjodyv and " Lithotomy," are splendid specimens of in which the various subjects are sy«temati5!ed and ij^^^criptive writing; while the chapter on "Stricture" arraneed We heartily recommend it to the profession jg ^ne of the most concise and clear that we have ever a" a valuable addition to the important literature of dis- 1 re&d.—New York Med. Journ., Nov. 1876. 73 F THE SAME AUTHOR. A PRACTICAL TREATISE ON FOREIGN BODIES IN AIR-PASSAGES. In 1 vol. 8vo., with illustrations, pp. 468, cloth, $2 75. THE T)RUrrT {ROBERT), M.R.C.S., Src. THE PRINCIPLES AND PRACTICE OF MODERN SURGERY. A new and revised American, from the eighth enlarged and improved London edition. Illus- trated with four hundred and thirty -two wood engravings. In one very handsome octa-vo volume, of nearly 700 large and closely printed pages, cloth, $4 00 ; leather, $5 00. practice of surgery are treated, and so clearly and perspicaoQsly, as to elucidateeveryimportanttopit. Wo nave examined thebook mostthoroughly, and can 4ay that this success i8 well merited. Hia book moreover, posaesses the inestimable advantages of having the subject* perfectly well arranged aud clatsifled and of being written in a style at once clear ind succinct. — Am. Journal of Med. Sciences. All that the surgical student or practitioner could desire. — Dublin Quarterly Journal. It is a most admirable book. We do not know irhen we have examined one with more pleasure. — Bonton Med. and Sttrg. Journal. In Mr. Druitt'sbook, though containlngonly some seven hundred pages, both the principles and the Henry C. Lea's Publications — {Surgery). 27 A SHHURST {JOHN, Jr.), M.D., -^^ Prof, nf Clinical Surgery, Univ. of Pa., Surgeon to the Episcopal Hospital, Philadelphia. THE PRINCIPLES AND PRACTICE OF SURGERY. Second edition, enlarged and revised. In one very large and handsome octavo volume of over 1000 pages, with 542 illustrations. Cloth, $6 ; leather, $7. {Just Ready.) Couscie»tiousne8s aud tlioronghnesR are two very I Ashbur-it's Surgery is too well known ia this marked traits of character in the author of this country to require special corameudatiou from us. book. Out of these traits largely has grown the ! Thig, its second edition, enlarged and thoroughly success of his mental fruit In the paet, and the pre- J revised, brings it nearer our idea of a model text- sent olfer seems in no wise an exception to what has j book than any recently published treatise. Though gone before. The general arrangement of the vol- j numerous additions have been made, the size of the ume is the same as in the first edition, but every part j work is not materially increased The main trouble has been carefully revised, and much new matter of text-books of modern times is that they are too added.— PAi/a. Med. Times, Feb. 1, 1S79. | cumbersome. The student needs a book which will ,. .. furnish him the mo.«t information in the shortest We have previously spoken of Dr. Ashhurst s | time. In every re-spect this work of Ashhurst is work in terms of praise. We wish to reiterate those , tjjg model text-book- full, comprehensive and com- terms here, and to add that no more satisfactory -..,._ . representation of modern surgery has yet fallen from the press. In point of judicial fairness^, of power of condensation, of accuracy and conciseness of expression and thoroughly good English, Prof. Ashhurst has no .superior among ihe surgical writers in America.— ^wj. Practitioner, Jan. 1S79. The attempt to embrace iu a volnme of 1000 page.? the whole field of surgery, general and special, would be a hopele.ss ta»k unless through tiie most tireless industry in collating and arranging, and the wisest judgment in condensing and excluding. These facilities have been abundantly employed by the author, and he has given us a most excellent treatise, brought up by the revision for the second editiou to the late.st date. Of course this book is not defcigned for specialists, but as a course of general surgical knowledge and for general practitioners, and as a text-book for students it is not surpassed by any that has yet appeared, whether of home or foreign authorship.— iV. Carolina Med. Journal, Jan. 1S79. pact. — Nashville Jour of Med. and Surg., Jan, The favorable reception of the first edition is a guarantee of the popularity of this edition, which is fresh from the editor's hands with many enlarge- ments and improvements. The author of this work is deservedly popular as an editor and writer, and his contributions to the literature of surgery have gained for him wide reputation. The volume now offered the profession will add new laurels to those already won by previous contributions. We can only add that the work is well arranged, filled with practical matter, and contains in brief and clear language all that is necessary to be learned by the student of surgery whilst in attendance upon lec- tures, or the general practitioner iu his daily routine practice. — Md. Med. Journal, Jau. 1S79. The fact that this work has reached a second edi- tion so very soon after the publication of the first one, speaks more highly of its merits than anything we might say in the way of commendation. It seems to have immediately gained the favor of stu- dents and physicians.— C'iyici?!. Med. News, Jan. '79 T>RYANT {THOMAS), F.R.C.S., -»-' Sxtrgeonto Guy's Hotpital, THE PRACTICE OF SURGERY. Second American, from the Sec- ond and Revised English Edition. With Six Hundred and Seventy-two Enj^ravings on Wood. In one large and very handsome imperial octavo volume of over 1000 large and closely printed pages. Cloth, $6 ; leather, $7. (Just Ready.) This work has enjoyed the advantage of two thorough revisions at the hand of the author since the appearance of the first American edition, resulting in a very notable enlargement of size and improvement of matter. In England this has led to the division of the work into two volumes, which are here comprised in one, the size being increased to a large imperial octavo, printed on a condensed but clear type. The series of illustrations has undergone a like revision, and will be found correspondingly improved. The marked success of the work on both sides of the Atlantic shows that the author has suc- ceeded iu the effort to give to student and practitioner a sound and trustworthy guide in the practice of burgery^ while the simultaneous appearance of the present edition in England and in this country affords to the American reader the benefit of the most recent advances made abroad in surgical science. There are so many text-books of surgery, go many i written by .skilled and distiuguished hands, that to ob- tain the honor of a third edition in England is no light praise. Mr. Bryant merits this, by clearness of style, and good judgment in selecting the operations he re- commends, iu his new editions he goes carefully over the eld grounds, in light of later research. On the.'^e and many allied points, Mr. Bryant is a calm and un- partisan observer, and bis book througboiit has the great merit of maintaining the true scientific, judicial tone of mind.— J/et/. and Surg, lieporttr 1879. The work before us is the American reprint of the last London edition, and has the advantage over the latter in being of more convenient size, and in being compressed into one volume. The author has rewrit- ten the greater part of the work, and has succeeded, in the amount of new matter added, in making it mark- edly distinctive from previous editions. A few extra pages have been added, and al.so a few new illustrations introduced. The publishers have presented the work in a creditable style. As a concise and practical manual of British surgery it is perhaps without an equal, and will doubtless always be a favorite text-book with the student and practitioner, — N. 1\ Med. Jiecord, .March i 22, 1S79. 1 Another edition of this manual having been calle.l for, the author has availed himself of the opportunity to make no few alterations in the sabstauce as we. I as in the airaugernent of the work, and, with a view to its improvement, has recast the materials and re- vised the whole. We ourselveb are of the opinion that there is no better work on surgery extant — Cihcinnati Med. News, March, 1879 Bryant's Surgery has been favorably received from M h '->■) i the first, and evidently grows in the esteem of the March — , ! profession with each succeeding edition. In glanc- ing over the volume before us we find prouf in almost every chapter of the thorough revision which the worK has undergone, many parts having been cut out and replaced by matter entirely fresh.- i\^. Y. Med. loam., April, 1879. Welcome as the new edition is, and as much as it is entitled to commendation, yet its appearance at this time is, in a ceriain sense, a matter of regret, as it will be in competition with another work, lately issued from the same press. But, the difficult task of forming a judgment as to the relative merits of Bryant and Ashuurst we will not attempt, but pre- dict that, considering the high excellence of both, many others will likewise be forced to hesitate long in making choice between \\iem.. -^Cincinnati Lan- cet and Clinic, March 22, 1579. 28 Henry C. Lea's Publications— (fifwr^'f?;-?/). fJRICHSEN {JOHN E.), Professor n/ Surgery in University College, London, etc. THE SCIENCE AND ART OF SURGERY ; being a Treatise on Sur- gical Injuries, Diseases, and Operations. Carefully revised by the author from the Seventh and enlarged English Edition. Illustrated by eight hundred and sixty two en- gravings on wood. It two large and beautiful octavo volumes of nearly 20<»0 pages : cloth, $8 50 ; leather, $10 50 (Noto Ready.) In revising this standard work the author has spared no pains to render it worthy of a continu- ance of the very marked favor which it hns so long enjoyed, by bringing it thoroughly on a level with the advance in the science and art of surgery made since the iippearance of the l:i5t edition. To accomplisli this has required the addition of about two hundred page« of text, while the illustrations have undergone a m:irked improvement. A hundred and fifty additional wood-cuts have been inserted, while about fifty other new ones have been substituted for figures which were not deemed satisfactory. In its enlarged and improved form it is therefore pre- sented with the confident anticipation that it will maintain its position in the front riink of text-bocks for the student, and of works of reference for the practitioner, while its exceedingly moderate price places it within the reach of all. The aeveuth editioa is before the world as the last Word ol surgical tcieuce. There may be uiouographs which excel it -up tn certain points, but as a con- spectus upun surgical principles and practice it is unrivalled. It will well reward practitioners to read it, for it bas been a peculiar province of Mr. Erichsen to demouhtrate the absolute interdepend- ence of medical and surgical science We need scarcely add, in conclasiou, that we heartily com- mend the work to students that they may be grounded in a sound faith, and to practitioners as an invaluable guide at the bedside.— .4m Practi- tioner, April, 1878. It is no i lie compliment to say that this is the best edition Mr. Erichsen has ever produced of his well- known book. Besides inheriting the virtues of is predecessors, it possesses excellences quite its own. Having stated that Mr. Erichsen his incorporated into this edition every recent improvement in the science and art of 8urgt'iy,it would be a supereroga- tion to give a detailed criticism. In short, we un- hesitatiugly aver th-it we know of no other single work wliere the student and practitioner can gain at oncesoclear an insight into the principles of surgery, and so complete a knowledge of the exigencies of surgical practice.— I/ontZ.^n Lancet, Feb. U, 1878 For the past twenty years Erichsen's Surgery has maintained its place astheleadingtext-book, notonly in this country, but in Great Britain. That it is able to hold its ground, is abundantly proven by the tho- roughneos with which the present edition has bean revit^ed, and by the large amount of valuable mate- rial that has been added. Aside from this, c ne hun- dred and fifty new illustrations have been inserted, including quite a number of microscopical appear- ances of path>l -gical processes. So marked is this change for the belter, that the work almost appears add to the value of this work, as an entirely new one. —ilferf. Record, Feb. 23,1878. I Journal, March, 1878. Of the many treatises on Sur-i;ery which it has been our task to study, or our pleasure to read, there is non« which in all points has satisfied us so well as the clas.'iio treati.'^e of Krich.''en. His polished, clear style, his free- dom from prejudice and hobbies, his unsurpassed grasp of his subject, and vast clinical experience, qualify him admirably to write a model text-book. "When we wish, at the least cost of time, to learn the most of a topic in surgery, we turn, by preference, to his work. It is a pleasure, therefore, to see that the appreciation of it is general, and has led to the appearance of another tali- tion.—Akd. and Surg. lieporter, Feb. 2, 1878. Notwithstanding: the increase in size, we observe that much old matter has been omitted. The entire work has been thoroughly written up, aud not merely amend- ed by a few extra chapters A great improvement bas t3een made in the illustrations. One hundred and fifty new ones have been added, and many of the old ones have been redrawn The author highly appreciates the favor wiih which his work has been received l)y Ameri- can surgeons, and has endeavored to render bis latest edition more than ever worthy of their approval. That he has succeeded admirably, must, we think, be the general opinion. We heartily recommend the book to both student and practitioner. — N. Y.JUed. Journal, Feb. 1878. Erichsen bas stood so prominently forward for years as a writer on Surgery, that his reputation is world wide, and his name is as familiar to the med- ical student as to the accomplished and experienced surgeon. The work is not a reprint of former edi- tions, but has in many places been entirely rewrit- ten. Recent improvements in surgery have not es- caped his notice, various new operations, have been thoroughly analyzed, aud their merits thoroughly discussed. One hundred and fifty new wood-cuts ■N. U. Med. and Surg. TIOLMES {TIMOTHY), M.D., J-^ Surgeon to St. George's Hosjntal, London. SURGERY, ITS PRINCIPLES AND PRACTICE. In one hand- some octavo volume of nearly 1000 pages, with 411 illustrations. Cloth, $6; leather, $7. {Just Issued.) This is a work which has been looked for on both sides ofthe Atlantic with much interest. Mr. Holmes Is a surgeon of large and varied experience, and one of the best known, and perhaps the most brilliant writer upon surgical subjects in England. It is a book for students— and an admirable one— and for the busy general practitioner. It will give a student all the knowledge needed to pass a rigid examina- tion. The book fairly justifiesthe high expectations that were formed of it. Its style is clear aud forcible, even brilliant at times, and the conciseness needed to bring it within its proper limits has no I impaired its force and distinctness.— iV. F. Med. Record, April U, 1876. It will be found a most excellent epitome of sur- gery by the general practitioner who has not the time to give attention to more minute and extended works and to the medicalstudent. In fact, we know of no one we can more cordially recommend. The author has succeeded well in giving a plain and practical account of each surgical injury and dis- ease, and of the treatment which is most com- monly advisable. It will no doubt become a popu- lar work in the profession, and especially as a text- book.— Cincinnati Med. News, April, 1876. ASHTON ONTHE DISEASES, INJURIES, and MAL- FORMATIONS OF THE RECTUM AND ANUS: with remarks on Habitual Constipation. Second American, from the fourth and enlarged London Edition. With illustrations. In one 8vo. vol. of 287 pages, el<^b,$3 25. SARGENT ON BANDAGING AND OTHER OPERA- TIONS OF MINOR SURGERY. New edition, with an additional chapter on Military Surgery. One 12mo. vol. of 383 pag9s, with 18i wood-cuts. Cloth, !JS175. Henry C. Lea's Publications — (Ophthalmology). 29 PfAMILTON {FRANK H.), M.D., ^■*- Professor of Fractures and DiHocntions, Ac, in BeUeviie Hosp. Med. College, New York. A PRACTICAL TREATISE ON FRACTURES AND DISLOCi- TIONS. Fifth edition, revised and improved. In one large and handsome octavo voluire of nearly 80a pages, with 344 illustrations. Cloth. $6 75: leather, $6 75. [Lately Issned.) This work is well known, abroad as well as at home, aslhe highe.«t authority on its important subject — an authority recognized in the courts as well as in the schools and in practice — and again manifested, not only by the demand for a fifth edition, but by arrang-ements now in pro- gress for the speedy appen ranee of a translation in Germany. The repeated revi.«ions which the author has thus had the opportunity of making have enabled him to give the most careful consid- eration to every portion of the volume, and he has sedulously endeavored in the present issue, to perfect the work by the aid of his own enlarged experience, and to incorporate in it whatever of value has been added in this department since the issue of the fourth edition. It will there- fore be found considerably improved in matter, while the most careful attention has been paid to the typographical execution, and the volume is presented to the profession in the confident hope that it will more than maintain its very distinguished reputation. There is no better work on the subject in existence tlinn tliat of Dr. Hamilton. It should be in the posses- sion of every irenenil practitioner and surgeon. — T/if Am. Journ. of Obstetrics. Feb 1876. The value of a work like this to the practical physi- cian and surgeon can hardly be over-estimated, and the necessity of havinir such a book revised to the latest date.'', not meri-lv on account ofthe practical importance of its teachings, but also by reason of the medico-legal bearingsof the cases of which it treats, and which have recently been the subject of usefulpapers by Dr IlaraiN ton and others, is sufficiently obvious to every one. The present volume seems to amply fill all the requisites. We can safely recommend it as the best of its kind in the English lantrnage. and not excelled in any other — Journ. of Nervous and Mental Disease, J&n 1876. ^EOWNE {EDGAR A.), Surgeon to the Liverpool Eye and Ear Infirmary, and to the Dispensary for Skin Disfasfg. HOW TO USE THE OPHTHALMOSCOPE. Being Elementary In- structionsin Ophthalmoscopy, arranged for the Use of Students. With thirty-fiveillustia- tions. In one small volume royal l2mo. of 120 pages : cloth, $1. {Now Ready.) This capital little work should be in the hands of ev ry medical student, and we had alniostsaid every general practitioner. Its explanation of the optical principles on which the ophthalmoscope is founded, i.r> 80 clear and simple that the most stupid reader could scarcely fail of understanding them. Equally satisfactory are the directions for the use of tie in- strument and the suggestions to aid in interpreiiiig what is tiQQa.—Dttroit Med. Journ., Kov. 1S77. o ARTER {R. BRUDENELL), F.R.C.S., Ophthalmic Surgeon to St. George's Hospital, ttc. A PRACTICAL TREATISE ON DISEASES OF THE EYE. Edit- ed, with test-types and Additions, by John Green, M.D. (of St. Louis, Mo.). In one handsome octavo volume of about 500 pages, and 124 illustrations. Cloth, $3 75. {Just Issued.) manner, ea.sy of comprehension, and hence the more valuable. We would especially commend, however, as worthy of high praise, the manner in which the thera- peutics of disease of the eye is elaborated, for here the author is particularly clear and practical, where other writers are unfortunately too often deficient. The liual ciiapter is devoted to a discussion of the usesand selec- tion of spectacles, and is admirably compact, plain, and useful, especially the paragraphs on the treatment of presbyopia and myopia. In conclusion, our thanks are due the author for many useful hints in the great sub- ject of ophthalmic surgery and therapeutics, a field where of late years we glean but a few grains of sourd w heat from a mass of chaff — New York Medical Hexord, Oct. 23, 1875. It would be difficult for Mr. Carier to write an unin- structive book, and impossible for him to write an un- interesting one. Even on subjects with which he is not bound to be familiar, hecan discourse with a rare degree of clearness and effect. Our readers will therefore not be surprised to \earn that a work by him on the Diseases ot the Kve makes a very valuable addition to ophthal- mic literature. , . . The book will remain one useful alike to the general and thespecial practitioner.— ion- don Lancet, Oct. 30,1875. It is with great pleasure that we can endorse ibe work as a most valuable contribution to practical ophthal- mology. Mr. Carter never deviates from the end he has in view, and presents the subjectin a clear and concise VfTELLS {J. SOELBERG), Professor of Ophthalmology in King's College Hospital, Ac. A TREATISE ON DISEASES OF THE EYE. Third American, from the Fourth and Revised London Edition, with additions ; illustrated with numerous engravings on wood, and six colored plates. Together with selections from the Test-types of Jaeger and Snellen. In one large and very handsome octavo volume. {Pre2>aring.) TA URENCE {JOHN Z.), F. R. C.S., Editor of the Ophthalmic Review, &e. A HANDY-BOOK OF OPHTHALMIC SURGERY, for the use of Practitioners, Second Edition, revised and enlarged. With numerous illustrations. In one very handsome octavo volume, cloth, $2 75. TA WSON {GEORGE), F.R.C.S. Engl., ■ Assistant Surgeon to the Royal London Ophthalmic Hospital, Moorflelds,Ac. INJURIES OF THE EYE, ORBIT, AND EYELIDS: their Imme- diate and Remote Effects. With about one hundred illustrations. In ^ne very hand- some octavo volume, cloth, $3 50. 30 Henry C. Lea's Publications — {Medical Jurisprudence). nURNETT {CHARLES H.), M.A ,M.D., J-^ Aural Surg, to the Presb. Hasp., Surgeon-in-tharge. ofthilafirforDis. of the. Ear, Phila. TPIE EAR, ITS ANATOMY. PHYSIOLOGY, AND DISEASES. A Practical Treatise for the Use of Medical Students and Practitioners. In one hand- some octavo volume of 615 pages, with eighty-seven illustrations : cloth, $4 60 ; leather, $5 50. {Just Ready.) Recent progress in the investigation of the structures of the ear, and advances made in the modes of treating its diseases, wouldseem to render desirable a new work in which all the re- sources of the most advanced science should be placed at the disposal of the practitioner. This it has been the aim of Dr. Burnett to accomplish, and the advantage.s which he has enjoyed in the special study of the subject are a guarantee that the result of his labors 1\- ill prove of service to the profession at large, as well as to the specialist in this der>artment. Foremost among the numerous recent coutribu- ; medical student, and its study will well repay the tions to aural literaturt will b^ ranked this work busy pracfitioner in the pleasuie he will derive from of Dr. Burnett. It is impossible to do justice to the agreeable style in which many otherwise dry this volume of over 600 pages in a nece>-!=arily brief and mostly unknown subjects are treated. To the specialist the work is of the highest value, and his notice. It must sufiice to add that the booh is pro- fusely and accurately illustrated, ihe references are conscientiously acknowledged, while the result has been to produce a treatise which will henceforth rank with the clas.sic writings of Wilde acd V^on Trolsch. — The Lond. rraitUiontr, May, 1S79 On account of the great advances which have been made of late years in otology, aud of the increased lutf rest manifested in it, the medical profes.-^ion will welcome this new work, whicli presents clearly aud concisely its present aspect, whilst clearly indi- cating the direction in which further researches can be most profitably carried on. Dr. Burn tt from his sense of gratitude to Dr. Burnett will, we hope, be proportionate to ilie amount of benefit he can obtain from the careful study of the book, and a constant reference to its trustworthy pages. — Edinbu gh Med. Jour., Aug. 1S7S. The book is designed especially for the use of stu- dents and general practitioners, and places at their disposal much valuable material. Such a book as the present one, we think, ha.>,l()ngbeen needed, aud we may congratulate the author on his success iu fiUiag the gap. Both scudent and practitioner can study the work witli a great deal of benefit. It is own matured experience, and availing himself of | pr^fu-ely and beaiitjfully iUustrated.-JS^ Y. Bos- the observations and discoveries of others, has pro- ^""' ^f"«"«. ^-'ct l->. li>". duced a work, which as a text-book, stands /ftct/c 'prinecps in our language. We had marked several pa-sages as well worthy of quotation and the atten- tion of the general practitioner, l)ut their number aud the space at our command forbid. Perhaps it is bet- ter, as the book ought to be in the hands of every 'piti Dr. Burnett is to be com mended for having written the best book on the subject in the English language, aud especially for the care and attention he has given to the scientific side of the subject. — N. 1'. Med. Journ., Dec. 1S77. BAYLOR {ALFRED S.),M.I)., Lecturer on Med. Jurisp. and Chemistry in Guy's Hospital. POISONS IN RELATION TO MEDICAL JURISPRUDENCE AND MEDICINE. Third American, from the Third and Revised English Edition. In one large octavo volume of 850 pages ; cloth, $ The present is based upon the two previous edi- tions; ''but the complete re vision rendered nece.ssary by time has converted it into a new work." This statement from the preface contains all that it is de- sired to know in reference to the upw edition. The works of this author are already in th«) library of every physician who is liable to be called upon for medico-legal testimony (and wh t 'nei.-i not?), so that all that is required to be knovvu about the present book is that the author has kept it abreast wiih the times What makes it now, as always, especially valuable to the practitioner is its conciseness and practical character, only thosfe poisonous substances Y THE SAME A U THOU. 5 60 ; leather, $6 50. {Just Issued.) being described which give rise to legal luvesliga- tions. — TAc Clinic, iXov. 6, 1S7.5. Dr. Taylor hat brought to bear on the compilation of this Volume, stores of learning, experience, and practical ac([uaiiitance with Lis subjectj probably far beyoud what auy other living authority on toxicol- ogy could have amassed or utilized. He has fully sustained his ret)Utaiion by the consum>nate skill and legal acumen he has displayed in the arrange- ment of tlio subject-matter, aud the result is a work ou Poisons whicli will be indispensable to every stu- dent or practitioner in law aud medicine. — 2"he Dub- lin Journ. i/ Med Sd., Oct. 1S7J, B MEDICAL JURISPRUDENCE. Seventh American Edition. Edited by John J. Reese, M.D., Prof, of .Med. Jurisp. in the Univ. of Penn. In one large octavo volume of nearly 900 pages. Oloth, $5 t(0 ; leather, $6 00. {Lately Issued.) To the members of the legal aud medical profes- best aaihority ou this specialty inour language. Ou sioD, It is unnecessary to say anything commend a- i this point, however, we will .-.ay thai weconsider Di . tory of Taylor's Medical Jurisprudence. We might j Taylor to be the safet«t medico-legal auttiority tofoi- as well undertake to speak of the nerit of Chitty 's j low, ingeneral, with which we are acquainted in any Ple-d,di\\g».—Chieago Legal News, Oct. 10, IS?."?. ' language.— Ka Clin. Record. Nov. 1{>73. It is beyond question themost attractive as well i Thislastedilion ofthe Manualisprobably thebest as most reliable manual of medical J urisprudence ^fj^n.^^ it c^u^j^in„ ,„^re material and i^ s* orked up published in the English language.— ^w. <;^owr«a/ , j^j tiig latest vi^^ws of the auihor asexpressed in the of Syphieography, Oct. 1873. | i^^^t edition of ih6 Principles. Dr. Uie^e, the editor It isaltogethersuperfluousfor u8toofi"eranything of the Alauual, has done everything to make his iu behalf of a work on medical jurisprudence by an work accept able to his medical countrymea.—.W. y, author who i* almost universally esteemed to be the Med. Record, Jan. lo, 1S74. or THE SAME AUTHOR. THE PRINCIPLES AND PRACTICE OF MEDICAL JURISPRU- DENCE, Second Edition, Revised, with numerous Illustrations. In two large octavo volumes, cloth, $10 00 ; leather, $12 00 This great woric is now recognized in England as the fullest and most authoritative treatise on every department of its important subject. In laying it, in its improved form, before the Amer- ican profession, the pablisher trusts that it will assume the same po.sition in this country. Henry C. Lea's Publications — i3fifinellaneous). 31 rPHOMPSON [SIR HENRY), •^ Surgeon and Professor of Clinicnl Surgery to University College Hospital. LECTURP]S ON DISEASES OF THE URINARY ORGANS. Witli illustrations on wood. Second American from the Third English Edition. In one neat octavo volume. Cloth, $2 26. (Just issued.) JDY THE SAME AUTHOR. ON THE PATHOLOGY AND TREATMENT OF STRICTURE OF THE URETHRA AND URINARY FISTULyE. With plates and ^Vood-cuts. From the third and revised English edition. In one very handsome octavo volume, cloth, $3 50. (Lately Published.) R OBERTS [WILLIAM), M.D., Lecturer on Medicine in the Manchester School of Medicine, etc. A PRACTICAL TREATISE ON URINARY AND RENAL DIS* EASES, including Urinary Deposits. Illustrated by numerous cases and engravings. Sec- ond American, from the Second Revised and Enlarged London Edition. In one large and handsome octavo volume of 616 pages, with a colored plate ; cloth, $4 50. (Lately Published.) mUKE [DANIEL HACK), M.D , ^ Joint author of ''The Manual of Psychological Medicine,^' Ac. ILLUSTRATIONS OF THE INFLUENCE OF THE MIND UPON THE BODY IN HEALTH AND DISEASE. Designed to illustrate the Action of tbe Imagination. In one handsome octavo volume of 416 pages, cloth, $3 25. (Lately Issued.) -DLANDFORD [G. FIELDING), M.D., F.R.G.P., J-^ Lecturer on Psychological Medicine at the School of St. George's Hospital, &c. INSANITY AND ITS TREATMENT: Lectures on the Treatment, Medical and Legal, of Insane Patients. With a Summary of the Laws in force in the United States on the Confinement of the Insane. By Isaac Ray, M. D. In one very handsome octavo volume of 471 pages; cloth, $3 25. It satisfies a want which must have heeu sorely felt by the busy general practitioners of this, country. Ic takes the form of a manual of clinical description of the various forms of insanity, with a description of the mode of examining persons suspected of in- sanity. We call particular attention to this feature of the book, as giviugit a unique value to the gene- ral practitioner. If we pass from theoretical eonside- ratious to descriptions of the varieties of insanity as actually seen in practice and the appropriate treat ment for them, we find in Dr. Blaijdford's work a considerable advance over previous writings on the subject. His pictures of the various forms of mental disease are so clear and good that no reader can fail to be struck with their superiority to those given in Mdinary manuals in the English language or (so far as our own reading exteudsjinany other. — London Practitioner, Feb. 1871. E A [HENRY C). 'superstition AND FORCE: ESSAYS ON THE WAGER OF LAW, THE WAGER OF BATTLE, THE ORDEAL, AND TORTURE. Third Revised and Enlarged Editior . In one handsome royal 12mo. volume of 552 pages. Cloth, $2 50. (Just Ready.) polemic. Though he obviously feels and thinks strongly, he succeeds in attaining impartiality. Wheti er looked on as a picture or a mirror, a work such as this has a lasting value. — LippincotVs Magazine, Oct. 1S7S. Mr. Lea's curious historical monographs, of which oiie ( f the most important is here reproduced in an enlarged form, have given him an unique position among Englisli and American scholars. He is dis- tingui.-jhed for his recondite and aftluent lea.rniDg, his power of exhaustive historical analysis, the breadth and accuracy of his researches among the rarer sources of knowledge, the gravity and temper- ance of his staiements, combined with singular earnestness of conviction, and his warm attachiueul; to the cau>e of human freedom and intellectual pro- gress.— iV'. Y. Tribune, Aug. 9, 1S7S. The appearance of a new edition of Mr. Henry C. Lea's "Superstition and Force" is a sign that our highest scholar.- hip is not without honor in its na- tive country. Mr. Lea has met every fresh demand for his work with a careful re*?iiiou of it, and the present edition is not only fuller and, if possible, more accurate than either of ihe preceding, but, from the thorough elaboration is more like a har- monious concert and less like a batch of studies. — The JS'ation, Aug. 1, 1S7S. Many will be tempted to say that this, like the 'Decliueand Fall,"isoae of the uucruicizable books Its facts are innumerable, its deductions simple and inevitable, and its chtvaux-dt-frise of references bristling and dense enough to make the keenest, stoutest, and best equipped assailant think twice before advancing. Nor is there anything contro- versial in it to provoke assault. The author is no B Y THE SAME AUTHOR. {LateyPrcbli.shed.) STUDIES IN CHURCH HISTORY— THE RISE OF THE TEM- PORAL POWER— BENEFIT OF CLEROY— EXCOMMUNICATION. In one large royal 12mo. volume of 516 pp.; cloth $2 75. . Tbe story was never told more calmly or with gr>ater learning or wiser thought. Wed'Mibt, indeed, if my other study of this field can be compared with tnis for clearness, accuracy, and power. — Chicago Examiner, Dec. 1870. Mr. Lea's latest work,-' StudiesinChurch History," fully sustains the promise of the first. It deal.- with three subjects — the Temporal Power. Beaefit of Clergy, and Excommunication, the record of which 1 as a peculiar importance for the English student, and Is a chapter on Ancient Law likely to be regarded as inal. We can hardly pasf^ from our mention of such w^rks as these — with which that on "Sacerdotal 0 Mhaov" should be included — without noting fhft literary phenomenon that the head of one ol the first American house.s is also the writer of some of its most original books. — London Athenceum, Jan. 7, 1871. 32 Henry C. Lea's Publications. INDEX TO CATALOGUE AmerlcaD Joarnal of the 3Iedical ScieDces Abstract, Mouthly, of the Med. Scieucei- Allen's Anatoniy .... Anatomical ^tlas, by Smith and Horner A»hion on the Kectum and Anu8 Attfield'B Chemistry .... Ashwell on Diseases of Females Ashhur.^t's Surgery .... Browne on Opiuhalmoscope . Browne on tlie Throat .... Burnett on the Ear .... Barnes on Diseases of Women Barnes' Midwifery, .... Bellamy's Surgical Anatomy Bryant 8 Practical Surgfery Bloxam's Chemistry .... Blaudford on Insanity . . . Basham on Renal Diseases . Brinton on the Stomach Barlow's Practice ol Medicine Bowman's (John E.) Practical Chemistry. Bowman's (John E.) Medical Chemistry Bristowe's Practice .... Humstead on Venereal Biimsiead and Cnllerier'sAtlasof Venereal carpenter's Human Physiology C irpenter on the Use and Abuse of Alcohol Cornil and Ranvier .... PA* Carter on the Eye . Cleland's Dissector Classen's Chemistry Clowes' Chemistry Century of American Medicine . Chad wick on Diseases of W.imen Charcot on the Nervous System . Chambers on Diet and Eegiinen . Chambers's Restorative Medicine Christison and Griffith's iJispeusatory Churchill's System of Midwifery Churchill om Puerperal Fever . Condie on Diseases of Children . Cooper's (B. B) Lectures on Surgery OiUerier's Atlas of Venereal Diseases Cyclopjedia of Practical Medicine' . Dalton's Human Physiology Davis's Clinical Lectures Dewees on Disease!" of Females . Druitt's ModernSurgery Dunglison's Medical Dictionary Ellis's Demonstrations in Anatomy Erichsen's System of Surgery Emmet ou Diseases of Women Farquh arson's Therapeutics Fenwick's Diagnosis Finlayson's Clinical Diagnosis Flint on Respiratory Organs Flint on tlie Heart Flint's Practice of Medicine. Flint's Essays Flint's Clinical Medicine Flint on Phthisis . Flint on Percussion Fothergill's Handbook ofTreatment Fothergill's Antagonism of Therapeutic Agents F jwnes's Elementary Chemistry Fox on Diseases of the Skin Fuller on the Lungs. &c. Green's Pathology and Morbid Anatomy Gibson's Surgery Gluge's Pathological Histology, by Leidy Gray's Anatomy Galloway's Analysis .... Griffith's (B..£.) Universal Formulary Gross on Urinary Organs . Gross on Foreign Bodies in Air-Passages Gross's Principles and Practice of Surg«ry Habershon on the Abdumen . Hamilton on Dislocations and Fractures Bartshorne's Essentials ofMedicine Hartshorne's Conspectus of the Medical Sciences Hartshorne's Anatoniy and Physiology Hamilton on Narvous Diseases . Heith'e Practical Anatomy Hoblyn's Medical Dictionary . dy Hodge on Women dodge's Obstetrics loUand's Medical Notes and Reflections . Ho'mes'e Surgery . . . . . Holden's Landmarks .... lorner's Anatomy and Histology Hudson on Fever Hill on Venereal Diseases . - . Hillier's Handbook of Skin Diseases Tones (C. Handtield) on Nervous Disorders Kirkes' Physiology Knapp's Chemical Technology . ' Lea's Superstition and Force Lea's Studies in Church History Lee on Syphilis .... Lincoln on Electro-Therapeutics Leishman's Midwifery . La Roche on Yellow Fever. La Roche on Pneumonia, &c. Laurence and Moon's Ophthalmic Surgery Lawson on the Eye Lehmann'6 Physiological Chemistry, 2 vols Lehmann's Chemical Physiology Ludlow's Manual of Examinations Lyons on Fever .... Medical News and Library . Meigs on Puerperal Fever . Miller's Practice of Surgery Miller's Principles of Surgery . Montgomery on Pregnancy Neill and Smith's Compendium of Med. Science Obstetrical Journal Parry on Extra-Uterine Prpguancy Pavy on Digestion Pavy on Food .... Parrish's Practical Pharmacy . Pirrie's System of Surgery . Playfair's Midwifery . Quain and Sharpey's Anatomy, by Le Reynolds' Practice of >'edicine . Robertson Urinary Diseases Ramsbotham on Parturition Remsen's Principles of Chemistry Rigby's Midwifery Rodwell's Dictionary of Science . Stimson's Operative Surgery Swayne's Obstetric Aphorisms . Seller on the Throat Sargent's Minor Surgery Sharpey and Quain's Anatomy, by Leidy Skey's Operative Surgery . Slade on Diphtheria Schfifer's Histology Smith (J. L.) on Children . Smith (H. H.) and Horner's Anatomical Atlas Smith (Edward) on Consumptio Smith on Wasting Diseases in Children Stilld's Therapeutics Stille & Maisch's Dispensatory Starges on Clinical Medicine Stokes on Fever . Tanner's Manual of Clinical Medicine Tanner on Pregnancy .... Taylor's Medical Jurisprudence Taylor's Principles and Practice of Med J Taylor on Poisons Tuke on the Influence of the Mind Thomas on Diseases of Females Thompson on Urinary Organs Thompson on Stricture . Todd on Acute Diseases Woodbury's Pr^ictice . Walshe on the Heart Watson's Practice of Physic Wells on the Eye . West on Diseases of Females West on Diseases of Children West on Nervous Disorders of Children What te Observe in Medical Cases Williams on Consumption . Wilson's Human Anatomy . Wilson's Handbook of Cutaneous Medicine Wiihler's Organic Chemistry Winckel on Childbed arisp HENRY C. LEA—Philadelphia. # it 157139