UNIVERSITY OF CALIFORNIA MEDICAL CENTER LIBRARY SAN FRANCISCO Medical Library Exchange Rush Medical College Library A VERY YOUNG OVUM IN SITU PROF.Cfc.l LEOPOLD GEHEIMER MEDIZINALRAT, DIRECTOR OF THE ROYAL GYNECOLOGIC CLINIC AND SCHOOL FOR MIDWIFERY. MEMBER OF THE ROYAL MEDICAL BOARD OF DRESDEN. COMPRISING THE FOURTH VOLUME OF THE "ARBEITEN AUS DER FRAUEN KLINIK IN DRESDEN." WITH SIXTEEN LITHOGRAPHIC PLATES AUTHORIZED ENGLISH TRANSLATION BY W. H. VOGT, M. D. GYNECOLOGIST AND OBSTETRICIAN TO THE LUTHERAN HOSPITAL ST. Louis, MISSOURI C. V. MOSBY CO. ST. LOUIS 1907 Privilege of Copyright reserved by S. HIRZEL, Leipzig, Germany, Oct. 10th, 1906. Act of March 3rd, 1905. CONTENTS PAGE Introduction - - 5-g Consideration of the Reconstruction of the Ovum From Section 1 to 160 - 10-33 CHAPTER I. The Mucosa Elevation, which Harbors the Ovum, and the Decidua Vera - - 34-42 II. The Embedding of the Ovum. The Capsularis. The Fibrinous Cover ("Gewebspilz" of Peters) 42-51 III. The "Eianlage" and the Ovular Chamber. ("Eikammer") 51-54 IV. The Trophoblast and its Surrounding Blood Spaces. The Intervillous Circulation 54-64 V. The Syncytium 64-66 Explanation of Figures 67-69 101276 INTRODUCTION. The Ovum which forms the subject of this investigation orig- inates from a young woman who committed suicide with phos- phorus. The post mortem examination was performed by -Ober- medizinalrat Prof. Dr. Schmorl, in the pathological institute . of the Friedrichsstaedter hospital in Dresden. The fact that this woman had committed suicide suggested the possibility of a pregnancy and for that reason the anterior wall of the uterus was split and the specimen carefully hard- ened, first in formalin and then in increasing strengths of alco- hol. Although repeated and careful examinations of the endo- metrium were made with a magnifying glass, no ovum could be detected. Still the greatly swollen mucous membrane which was divided into irregular areas by furrows, as we are accus- tomed to see in a pregnant uterus, was conspicuous and induced us to make repeated examinations during the process of harden- ing. Finally a small spot was detected, lighter than the sur- rounding tissue, situated on the posterior wall of the corpus uteri a little below its center and immediately above a deep furrow. In order to study this small spot more carefully, a square piece of mucous membrane about 1 cm. long, with its underlying mus- cularis was excised and after further hardening by the labora- tory assistant, Mr. Ernst Thomas, cut into a continuous series of sections, five microns thick and then stained in haematoxylin- eosin. The middle one hundred and sixty sections comprised a very small ovum whose measurements were 1.4 mm. long 0.9 mm. deep and 0.8 mm. wide, an ovum about the size of that described by Peters, however a trifle smaller, its length being 0.2 mm. shorter than that of Peters, which measured 1.6 mm. in length, 0.8 mm. in depth and 0.9 mm. in breadth. No information could be obtained concerning the time of the last or first missing menstruation. Hence it seems useless to attempt any estimate of the age of this ovum. In the following pages it is intended to compare the results of the microscopic examinations with those of Peters, since this one and the one described by him are the two smallest and youngest human ova ever observed. 5 D INTRODUCTION. The accompanying plates were carefully drawn by the artist, Richard Scholz, exactly true to nature and without any attempt to obtain a diagramatic effect. I wish to thank the artist, as well as the publisher, for the ex- cellent reproduction of these figures and for the valuable ser- vices they have thereby rendered science. There will be considered: 1st. The Decidua Vera. 2nd. The Implantation of the Ovum with the formation of the capsularis and the fibrinous covering, which lies over the ovum on the mucous membrane. ("Gewebspilz" of Peters.) 3rd. The "Eianlage" and the Ovular Chamber "Eikammer." 4th. The Trophoblast and its surrounding blood spaces. 5th. The Syncytium. A germinal plate which was found in Peters' specimen could not be discovered in any of the sections of this new ovum. Whether its absence be possibly due to the general phosphorus poisoning must remain an open question until more specimens of such an early stage are obtained. It must be remembered that the woman from whom the Peters ovum was obtained, also committed suicide, but with caustic potash, which is capable of producing a very acute hyperemia of the mucous membrane of the pelvic organs. Some of the ova described by Marchand, Rossi Doria, Graf von Spec, Heukelom, Mertens, etc., can hardly be pronounced normal specimens free of objections. The indications for the post mortem in such instances will necessarily be either a suicide or an acute illness caused by poisoning or some intercurrent dis- ease (such as pneumonia, burns, etc.), or a disease of the sexual organs necessitating a removal of the uterus. All of these con- ditions, especially in the early stages of pregnancy, will hardly ever fail to lead to some changes in the circulatory apparatus of the uterus. Nevertheless some portions of both the uterus or the ovum may be found in a very satisfactory state of preservation. Of the three young ova described by Marchand, the first had a defective fibrinous capsule, supposedly injured during a curet- age. The second was infiltrated with blood and yet Marchand did not hesitate to investigate these defective specimens, to study such difficult problems as the trophoblast and the syncytium and finally drew, although with great precaution, certain conclu- sions. In order to satisfy myself of the value of this specimen I sub- mitted several sections to my esteemed colleagues, Obermedizin- alrat Prof. Dr. Schmorl and Prof. Graf von Spec in Kiel, whom INTRODUCTION. t I wish to thank for a careful examination of these slides. Prof. Graf von Spec did not question in the least the good histological preservation of this specimen. He called attention to the great scientific value of this new ovum and pointed out the frequent oc- currence of a congested area surrounding the seat of implantation in this stage of development. The ovum of Peters, which may be one-half to one day older, also shows this marked congestion of the blood vessels in the immediate neighborhood of the ovum. We must bear in mind that during or immediately after the penetration of the ovum into the endometrium, a pronounced af- flux of blood is a natural consequence. Regarding this only a study of other very young ova, which can be expected in the near future, will throw more light on this problem, until then it seems permissible to disregard the objection that the poison- ing with phosphorus might interfere with the reliability of the histological picture presented by our specimen. At any rate it must be emphasized, that this latest ovule, exactly like that of Peters', the one demonstrated by Graf, von Spec in Kiel, and the very small ovum described by me in my atlas ("Uterus und Kind") were found in' situ embedded in an uninjured mucous membrane in a perfect condition. The detailed discussion in the following chapter will be simpli- fied by a general preliminary consideration of the mucous mem- brane elevation which harbors the ovum. This is done in the following table, which contains only the findings pertaining to this point in the sections 1 to 160. This table shows plainly that the fibrin coat ("Gewebspilz" of Peters) which covers the top of the mucous membrane elevation ("Schleimhauthuegel") consists of two adjoining portions. The one we can follow from sections 10 to 68, where it has almost dis- appeared. The second portion begins in section 75 and disap- pears again completely in section 103. In a similar manner the glands and the blood vessels can be followed. This preliminary general consideration furnishes a good picture of the enormous number of glands and capillaries and shows how the glands gradually are crowded out through the dilatation and rupture of the capillaries in the surrounding tissue. This general survey alone demonstrates the fact that the mi- nute ovum is completely encircled by free blood spaces. It affords me great pleasure to say a few words regarding the translation of my book, which Dr. Vogt has so kindly under- taken. A few years ago Dr. Vogt was a pupil of mine who for many months assisted me both in theoretical and practical work. I shall owe to this translation a widespread acquaintance with 8 INTRODUCTION. this highly interesting specimen, herein described, among my many friends and former pupils, as well as my colleagues on the other side of the ocean. It is hoped that this book will instigate further research con- cerning the earliest stages of human existence. PROF. DR. LEOPOLD. Dresden, Koenigliche Frauenklinik, January, '07. TRANSLATOR'S PREFACE. The deplorable fact that numerous important contributions to medical literature," appearing in the German language, remain unread by the English-speaking fraternity as the result of an im- perfect acquaintance with that tongue, induced me to undertake the translation of this valuable study of one of the youngest human ova found in situ. When requested to do this work by my esteemed former chief, Prof. Dr. Leopold, I was impressed with the necessity of preventing the English-speaking profession from remaining unacquainted with a work of such high order. This book should prove interesting and instructive not only to the embryologist and the obstetrician, but also to the profession in general, and if by its translation I shall have succeeded in dis- seminating a clearer knowledge of this complex subject, I shall feel amply repaid for my labor. In conclusion I wish to thank my friend and colleague, . Dr. Hugo Ehrenfest, for the very kind and valuable assistance which he rendered me in the translation of the book, and I also wish to express my indebtedness to Mr. Geo. Heithaus, stud. med.. for his aid in the reading of the proofs. W. H. VOGT, M. D. St. Louis, Mo., September, 1907. 4977 Lotus Ave. 10 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTIONS 1-160. No. of Section. Mucous i Without fibrin cover. nembrane elevation narbonn With fibrin cover. y the ovum. Epithelium above. Epithelium beneath? I. — — — — 3- — . — — — 4- — — — — like i and 3. 6. — — The mucous membrane protuberance which later be elevation, enci um. comes the ovular rcled by epitheli- 7- Mucous membrane becomes thicker. Epithelium varying in thickness. — 8. — — Epithelium varying in thickness. — Q. — — The well pre- served surfact which a large g over the elevat ; epithelium in land opens passes ion. IO. — Suddenly a thin fibrin cover appears over ele- vation ("Gewebspilz" Peters'.) — Under which a trace of sur- face epitheli- um is to be . seen. II. — Firbin cover increases in thickness toward right. Over fibrin cover epithe- lium varying in thickness. Not clear. 12. — Present. — — 11 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. In the small elevation on the surface of the mucous membrane, glands and capillaries plentiful; glands with per- fect epithelium. — — i. Capillaries already considerably di- lated. Glands as in i. — — 3- Numerous capillar- ies in elevation of mucous mem- brane surface. Greatly dilated glands with per- fectly preserved epithelium. — Fig- 3- 4- « •• — — like i and 3. 6. Blood and capil- laries present. No glands in sum- mit of ovular ele- vation. Dilated gland in depth of section. Here the first suspicion of Eianlage by presence of syncytial cells. Accumula- tion of leucocytes. — 7- Dilated capillaries in elevation and communicating bl< ed with syncytial c X)d spaces infiltrat- ,ells. Scattered syncytial cells, accumulation of leuco- cytes. — 8. Blood spaces in ele- vation, whose in- tervening walls contain fibrin. A large gland opens into eleva- tion on the same well preserved surface epitheli- um. Scattered syncytial cells. Tissue of elevation some- what infiltrated with blood. — Q. In the mound con- fluent vessel spaces. — Infiltrated with trophoblast processes with a layer of syncytial covering. Fig. 4. 10. Capillaries become dilated in eleva- tion. Glands in eleva- tion and sur- rounding, num- erous and plain- ly visible. . The inner blood space in the ovular elevation surround- ed with syncytial cells. — 1 1. Blood spaces as in 1 1. — — — 12. 12 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Mucous membrane elevation harboring the ovum. No. of Section. Without fibrin cover. With • fibrin cover. Epithelium above. Epithelium beneath? 14. — Present. — Band of epi- To the left and thelium on under the fibrin the fibrin covering sur- 15- — Present. cover which face epithelium. sinks into the right somewhat swollen end of the fibrin cover like the mouth of a gland. Instead of as • above, there is 1 6. — Present. found only a slight funnel-like depression of tissue cells anc blood cells. Still somewhat '7- — Present. of a funnel-like depression of tis- sue cells. Somewhat of a " depression cov- 1 8. — An entirely structureless — ered with epi- mass. thelial-like cells. To the left un- der the fibrin cover, epithe- iQ. ' " funnel-like dep lium present, ression still pres- ent. In it or rather between it and the fibrin cover many blood cells. Under the fibrin Present. — cover a long epithelial like band, which At certain parts aggrega- probably originates from the 20. — tion of leucocytes. Oc- syncytial offshoots which closely casionally large syncy- approach the fibrin cover and tial cells, but without a may easily be mistaken for uter- nucleus. ine epithelium. 13 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. — — Trophoblast with syncytial offshoots. Blood present. — 14. Decidual cells between the dilated capil- laries and glands. Processes of trophoblast with offshoots. Fig- 5- 15- — — — — 1 6. — — At the periphery of the ovu- lar chamber, syncytial cells found. — >7- On the border of the various cap- illaries syncytial cells, partly aris- ing from endo- thelium. — — — 18. Same. Numerous elonga- ted and some greatly dilated glands. Same. Fig. 6. 19. — — Trophoblast with syncytial offshoots pass well up un- der the fibrin covering. — 20. 14 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Section. Mucous membrane elevation harboring the ovum. Without fibrin cover. With fibrin cover. Epithelium above. Epithelium beneath? Present. Becoming steadily longer and lies like a worm with its thick end on the right of the ovular elevation. Epithelium varying in thickness on the fibrin cov- An epithelial- like band com- ing from both sides under the fibrin cover. Most likely syncytial cells. 23. 24 and 25. In elongated part, connec- tive tissue arrangement. Leucocytes, and in the club end fibrin only. Be- tween these two parts as well as towards the ovu- lar elevation many red blood cells. Epithelium Under the fib- varying in rin cover long thickness on streaks of epi- the fibrin cov- thelial-like er. cells. Close on to these the long stretched syncytial cells with large nuclei reach, which come from the trophoblast. The elongated part be- comes more and more or- ganized, the club end is still fibrinous but is al- ready infiltrated with white blood cells. Epithelium varying in thickness above. The same. 26. The fibrin cover becomes Epithelium constantly longer and ' varying in has at its right end a but- thickness, ton-like thickening con- taining many red blood cells. The left end a structureless elongation. Therefore only the middle part is organized. As in 23. 27. Fibrin cover very much elongated, on the right end knob-shaped, folded like a corpus luteum, in the center of fold, blood cells. The left end sends out an offshoot and be- comes steadily longer. Epithelium varying in thickness fi b r i n An epithelial- like band un- der fibrin cov- er. Under the elongated left o n cover. end of the fibrin cover this band contains a few cells with a dis- tinct nucleus and under the same, running parallel with it, are seen the large syncytial cells. 28 and 29. same as 27- 30. Fibrin cover as in 27. Blood found in fold of knob end. At the base of fibrin cover are found syncytial clubs with many nuclei. Close by, an epithe- lial-like band. Epithelial-like band to left under fibrin cover. Probably having some connection with the giant syncytial cells. 15 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. Vessels dilate, their walls become thinner and rup- ture. Blood es- capes and passes into the neigh- boring glands. — Eianlage, with projection, now seen cut laterally. Fig- 7- 22. Endothelium of the capillaries en- larged. Contains large nuclei. Glands to the side of the ovum may be seen almost in their entire length. Various others filled with blood. Eianlage has a projection with a broad end. Ovular chamber filled with blood. — 23. " " Eianlage with trophoblast buds and projections which anchor themselves in the periphery of the ovular chamber. Projections with trophoblast nuclei and syn- cytial covering. — 24 and 25. At the broad base the blood vessels become more con- fluent and take up the protruding trophoblast proc- esses. To the left and right of ovum ex- cellently pre- served, some bro- ken open and filled with blood. Eianlage, larger and takes on a more definite form. — 26. Toward the ovular chamber the con- fluent blood ves- sels are now divid- ed by an arch-like arrangement of fibrin. » Eianlage as in 26, passing from it to the fibrin cover are five trophoblast proces- ses with offshoots of syncy- tium. In the surrounding of the Eianlage decidual cells. Fig. 8. 27. Passing from the Ei blast processes and s free blood, likewise i anlage to the knob e yncytial offshoots are n the fold of the fibr Eianlage manifold, elongat- ed and somewhat com- pressed by free blood, nd of the fibrin cover, tropho- seen. Between the offshoots n cover. Section 26-28. Fig. Q and Fig. 10. Section 3°- Fig. n. 28 and 29 same as 27. 30. 16 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Mucous membrane elevation harboring the ovum. Section. Without fibrin cover. With fibrin cover. 1 Epithelium above. Epithelium beneath? Between fibrin cover and 3>- — periphery of the ovular chamber, many processes of syncytium with many — — nuclei. 32. — • Between fibrin cover and neighboring border many syncytial giant cells. Band of epithe- lium not dis- tinct. To the right un- der the fibrin cover, presum- ably a rem- nant of epi- thelium. 33- — Present. Below and above fibrin cover no band of epithelium left. 34- — Giant syncytial cells reach to fibrin cover. — Absent. Only toward and under fib- 35- Present. rin cover are 4 epithelial-like formations. 36. — Present. Elongated with club- shaped end. — Is similated by rows of epithe- lial-like syncy- tial cells. Present. Under the knob 37- — . Elongated with knob end, which appears like a thick fibrin band. Band of vary- ing thickness. end an epithe- lial-like band surrounded by blood cells. The elongated part of the fibrin cover here resem- 38. — bles some of the previous specimens. The knob- like end is more fibrinous — — but is already beginning to be infiltrated with , leucocytes. 17 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160 Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. — — Tropholbast processes. Coat elevated by blood and con- sists of two layers. Row of nuclei with syncytial cov- ering. — 31- — — Trophoblast processes with offshoots pass toward per- iphery, where fibrin cover lies. Coat elevated, 2 lay- ers: Langhans' cells and syncytial covering. Fig. 12. 32. — — Eianlage with partly elevat- ed coat. — 33- — — — — 34- Blood vessels dis- integrating. — Processes of trophoblast. — 35- — — Mesoblast and Ectoblast (Trophoblast and Syncytial cells) pass under entire fib- rin cover along the wall of the ovular envelope. — 36. Owing to the in- creasing size of the ovum the sur rounding blood vessels become more and more disintegrated, to the ovum but doe ovular chamber. To the right and left of ovum two glands. In the middle of these a third gland which gradually dilates and passes s not open into the — Fig. 14. 37- • — The same. The syncytial cells pass up to the ovum periphery and make the impression of sur- face epithelium. — 38. 18 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Section. Mu Without fibrin cover. :ous membrane elevation har With fibrin cover. boring the ovum. Epithelium above. Epithelium beneath? 39- the one side of wh arising from the t Present. Under the long offshoots of the fibrin cover a long blood vessel present, ich consists of broad cells 'ophoblast. Over the knob end a worm- like cover. — • 40. i — The elongated part of the fibrin cover is made up of distinct tissue. The knob end is arranged ex- actly like a corpus lute- um. Over the knob end a band varying in thickness. Under the knob end reaching from the bor- der, an epithe- lial band. 41 like 40. — Same. Under the entire fibrin cover, large svncy tial cells are seen. — — 42. — Under the knob end syn- cytial giant cells. — — 43- — The knob end of the fibrin cover is infiltrated with leucocytes. — — 45- — Under the fibrin cover the row of syncytial cells have become consider- ably larger. — — 47- '— Present. — — 49- — Present. gated syncyti might be mist epithelium. Under the fib- rin cover elon- al cells, which aken for surface 5«- — The knob end becoming shorter and rounder. — Elongated syn- cytial cells be- low. 19 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160 Blood vessel. Glands. Eianlage. Illus- tration. No. of Section. — Left gland with broad opening. Right gland surro die one which reac with blood. unds entire ovum. The mid- hes to the ovum becomes filled Fig. 13. 39- — — From the trophoblast an ex- tension of syncytial cells pass to the epithelial-like band on the border under the knob end. — 40. — — As in 40. — 41 like 40. — — Covering with syncytial buds. — 42. — — — — 43- of the ovum can be the entire length tc The two glands to the right and left followed almost in their openings. Covering has two rows. — 45- A broad part of the contact a double ce visible. Here as in which anchor them; ovum lies under the 1 row (Langhans* eel 48 one' sees large of elves into the peripri Processes of trophoblast with offshoots, fibrin cover. At the point of ,s and Syncytium) are plainly "shoots, from the trophoblast, ery of the ovum. Fig. 1 6. 47- — — Offshoots with covering which become anchored. (Section 50.) — 49- In the periphery of the ovum toward the middle of the mucosa uteri, an enormously dilat- ed vessel. — Eianlage with offshoots as heretofore. — 5'- 20 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160 No. of Section. Mu Without fibrin cover. cous membrane elevation hai With fibrin cover. boring the ovum. Epithelium above. Epithelium beneath? 52. — Under fibrin cover enor- mous syncytial cells. — — 53- — The fibrin cover becomes more compressed. (Al- most structureless.) Giant syncytial cells be- low. — — 54- — The knob end rounder and thicker, under the same thick syncytial cells, with many nuclei. — — 55 and 56. — Under the fibrin cover the syncytial cells constant- ly increasing in number. — — 57- — Under entire length of fib- rin cover larger and smaller syncytial cells are found. Over knob end of fibrin cov- er a band of epithelium varying in thickness. — 58 and 59. — Fibrin cover compressed, shortened and thickened. Beneath syncytium. — — 60. structureless knob has become organi syncytial cells are The fibrin cover now pre- sents itself as an almost the rest of the fibrin cover zed. Under this cover the constantly multiplying. — — 6 1 and 62. — Among these syncytial cells trophoblast cells are observed. — — 63. — The knob end like a but- ton. Under the same rows of syncytium, which pass almost to the outer border of the covering. — — f 21 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Einlage. Illus- tration. No. of Section. — — Band of ectoblast with Lang- hans' cells and syncytium. In Eianlage peculiarly ar- ranged cells. Embryonic rudiment? Fig. 26. 52. — — Eianlage lies plainly on the periphery with a covering of two layers. — 53- The enormously di- lated blood ves- sels as in 51. — Trophoblast processes with syncytium anchored to per- iphery of ovum. — 54- • — — 55 and 56. Dilated capillaries. well preserved unc due to the confluen Enormously dilated present in 51. Beautifully ar- ranged, partly ergoing dissolution t blood vessels, blood vessels still The albuminous mass in the Eianlage compressed by blood in the ovular cham- ber. — 57- — To the left and right of ovum, glands with open- ings. Eianlage with trophoblast processes and syncytial off- shoots. — 58 and 59. The enormously di- lated blood ves- sels divided into three spaces by the decidual tis- sue. — Eianlage with trophoblast processes. Syncytial cov- ering. Fig. 17. Fig. 27. 60. — The two glands to the left and right are distinctly visible. Eianlage, as in 60. — 6 1 and 62. — The same. Eianlage with trophoblast and offshoots. Fig. 1 8. 63. 22 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Section. Mu Without fibrin cover. cous membrane elevation hai With fibrin cover. boring the ovum. Epithelium above. Epithelium beneath? 65 and 66. — The knob-like end becomes flatter. — — 67 and 68. — The knob becomes still flatter and is hardly vis- ible in 68.. Beneath it a layer of syncytium. — — 69. — The knob but a small structureless fibrinous elevation. Layer of syn- cytium beneath it. — — 70-73. — The knob is as 69. Be- neath it syncytium, which might be mistaken for uterine surface epithelium. In 73 a layer of epithelium varying in thickness. — * 74- — The knob as in 73. As in 73. — 75- becomes longer an cover. The fibrinous structureless mass, which has been but a tiny knob, again d lies on the organized fibrin — — 76-79. — The fibrinous structureless mass becomes steadily longer. Syncytium is seen beneath this mass. A band of epi- thelium vary- ing in thick- ness. Similates uter- ine surface epi- thelium. 80. — The structureless mass be- comes steadily longer and begins to appear as be- fore. (See sections 10-25.) An epithelial- like band. — Si. — — — — 82 and 83. — — — — 84. — Fibrin cover with a band lying above it. A few cells be- neath. (Epi- thelial cells?) 23 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160- Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. — — — — 65 and 66. — Glands plainly vis- ible to the right and left. Eianlage toward the sum- mit with trophoblast. — 67 and 68. — Glands plainly vis- ible to the left; to the right they are displaced. Eianlage with beautiful tro- pholbast processes and off- shoots with syncytium. Fig. IQ. 69. — The same. The same. — 70-73. — — Numerous syncytial cells scattered in the surround- ing of the ovum. — 74- — The same. Eianlage with trophoblast processes. Fig. 20. 75- — — — ' — 76-79. — The same. The same. Fig. 21. 80. — — Polymorphous and pressed together by Eianlage and ectoblast. The latter ar- ranged like numerous prongs. Trophoblast proc- esses. (View of entire ovum.) 81. — — Large trophoblast processes with syncytial offshoots extending to the border and walls of the blood ves- sels. — 82 and 83. — — Trophoblast processes with syncytium plainly visible, In the periphery of the ovu- lar chamber large syncy- tial cells. — 84. 24 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Section. Without fibrin cover. With fibrin cover. Epithelium above. Epithelium, beneath? 85. — — — — Under fibrin cover a chain 86 and 87. — The fibrin cover becomes longer and on its right end has a knob - like thickening. Epithelium spreading above it. .of cells (Epi- thelium?) At the right bor- der a distorted gland. Blood has entered it. 88. band a fine layer ol ed syncytial cells c Fibrin cover larger. Toward the epithelial fibrin is seen;- then elongat- ccasionally trophoblast. A long band of epithelium over it. Under it a torn epithelial band however in better pres- ervation. Under the fib- rin cover, os- 89. Present. tensibly an ep- ithelial layer. Present? 90-92. — Elongated. Present. Immediately below it are biids of syncy- tium. 93- — Larger. 4 Epithelium above and beneath the fibrin cover. 94. — Distinct. — — 95 and 96. — The same. Present. Present. CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Eianlage. Illus- tration.' No. of Section. To the right be- tween the ovular chamber and the adjoining glands new capillaries are constantly be- ing opened. The large gland to the left of the ovum reaches to the border. The almost in its enti becomes lost th periphery. inland to the right can be seen re length. The middle gland e nearer it approaches the — 85. Confluent capillar- ies at the border becoming dis- solved. Also from the endott near the border ol cells are seen prol syncytial cells. Long glands to the right and left. The middle one does not quite extend to the ovum. elium of the vessels the ovum cavity, ferating, similating — — 86 and 87. — — The offshoots of a long tro- phoblast plug radiates toward a vessel. — 88. — etrates an adjoin wall has been pen its neighbor. Lar at other places. The syncytium passes from a trophoblast plug and pen- ing vessel. After the vessel etrated it communicates with ge clusters of syncytial cells — 89. — The three glands as in 86 and 87. border. The sync group of vessels in corroded by two s Long trophoblast processes with syncytium at the ends. Becomes anchored at the vtium corrodes a vessel. A the border are likewise being yncytial offshoots. Fig. 28. 90-92. Vessels in dissolu- tion in the border. The glands to the right are seen in their entire length. Like- wise the left. The middle glands disappear. Long trophoblast processes anchor with syncytium. Fig. 22. 93. — The middle gland becomes lost toward the bor- der of the ovum. Mesodern distinct and poly- morphous. At the border large trophoblast plugs with syncytial covering become anchored to the ovum per- iphery. 94- — The middle gland at the border of the ovum with large epithelial cells. Trophoblast at the border of the ovum (near the fibrin cover) has two hook-like plugs between which is found considerable blood. Fig. 23. 95 and 96. 26 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Mucous membrane elevation harboring the ovum. Section. Without fibrin cover. With fibrin cover. Epithelium above. Epithelium beneath? 97 and 98. Fibrin cover has sunk into the underlying tissue. Bands of epi- thelium vary- ing in thick- Bands of epi- thelium. ness. 99. — Fibrin cover elongated. Likewise. Bands of epi- thelium vary- ing in thick- ness. 100. — Present. Fibrin strip has a layer of epi- thelium. Likewise below. IOI. — Fibrin cover depressed. To the left epithelium. — Epithelium (?). beneath the fibrin strip. Under the fib- 1 02. ~ Small fibrinous elevation. rinous eleva- tion, strips of epithelium (?) 103. Fibrin cover en- tirely absent. Only a tiny particle there- of present. — Short bands, (Surface epi- thelium?) 104 and 105. Absence of fibrin cover. — — — 1 06 and 107. The same. • — Surface epithe- lium fairly well pre- served. — 1 08. The same. — I 10 and The same. — — • — in. 27. CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160 Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. cells close to the ov lost however the cl the ovum. To th« the left i to 2 glanc Middle gland has large epithelial um, which become aser they approach : right 2 glands, to s. Trophoblast processes with syncytium. — 97 and 98. — Three glands. Trophoblast processes with syncytium. — 99. — Three glands. The middle one begins to disap- pear. Trophoblast processes. Syn- cytium reaches to the bor- der. — 100. — Three glands. Beautiful tropholbast proc- esses. — 101. — The middle gland is seen plainly reaching to the ovum. Trophoblast processes reach almost to the border of the ovum. Syncytial buds reach to the under border of fibrinous elevation. — 1 02. — The middle glands not so plainly visible. The trophoblast and syn- cytium reach to the band beneath the beginning of the fibrin cover. — 103. — The middle gland reaches almost to the ovum. — Fig. 24. 104 and 105. — Two new glands are seen on the border of a dilat- ed vessel. Trophoblast processes with syncytium and giant cells. — 106 and 107. seen. In later sec comes more plainly length. The end of a large gland is plainly tions this gland be- visible in its entire Trophoblast processes. — 1 08. Capillary spaces. The gland very distinct, the opening however has become less distinct. Other glands with their epithelium have become destroyec through hemor- rhage. Buds of syncytium. — I 10 and in. 28 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Section. M Without fibrin cover. ucous membrane elevation ha With fibrin cover. rboring the ovum Epithelium above. Epithelium beneath? I 12. Not a suspicion ol a fibrin cover. — — — 113. The same. — — i 14-1 i 6. 1 17 and 1 1 8. The same. — — — IIQ. — A trace of fibrin present. — — 121 and 122. Not a trace of fib- rin except on ovular elevation. — — — 123. and 124. The same. — — — 125-128. — — — — 129-131. — — — — 132. — — — — 133. — — — — 29 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessel. Glands. Eianlage. Illus- No. of tration. Section. | The mouth of the gland disappears. In a gland filled with blood, the epithe- lium cells are swollen, partly enlarged and elevated from base. Buds of syncytium. A gland at the bor- der. Close to the pole of the ovum, a gland lined with epi- thelium and greatly dilated, is seen filled with blood. 113. Dilated capillaries surround the ov- um. A large long gland close to the ovum Syncytium anchor. i 14-1 16 117 and 1 1 8. The mouths of two glands on top of the ovum. Delicate processes 'become anchored to the periphery. 119. Cavernous Wood spaces in the per- iphery of the ov- um. A gland opening. Between the cavernous blood spaces the syncytium is ar- ranged in arches. 121 and 122. Cavernous blood spaces surround- ing the ovum. Many capillaries open in the sur- rounding of the central blood space. Two gland open- ings close to top of the ovum mound. 123 and 124. To the right of the ovum a gland with a distinct opening alone; capillary. passes a dilated The interior of the ovum filled with blood, this is enclosed by arch-like ar- ranged syncytial cells. 125-128. A number of capil- Glands as in 132. laries open at a place which was previously occupied by the nucleus of the Eianlage and break into discern- ible glands. Syncytial cells become less. In the periphery Still more syncytial cells of the ovular ele- with large well stained nu- vation four clei. glands are plainly visible partly a.) dissolved in capillaries, at their opening or in the center, b.) fairly well traceable in their entire length, c.) not plainly visible, d.) opening not distinct, toward the interior dilation plainly visible. 132. Capillaries break into glands. Syncytial cells with large nuclei. '33- 30 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Section. Mu Without fibrin cover. cous membrane elevation hai With fibrin cover. boring the ovum. Epithelium above. Epithelium beneath? 134-136. — — — — 137-I39- — — — — 140. — — — — 141. — — — — 142 and 143. The mucous membrane elevation upon which no fibrin cover is present, shows a few conflu- ent blood spaces in the center, besides this beautiful glands and numerous blood ves- sels. — — 144 and 145. — — — — 147. — — Rests of sur- face epithe- lium. — 151. Divided blood spaces in the ovular elevation. — — 152. — — — — '51 and •55- — — Surface epithe- lium present over ovular elevation. — , 31 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Eianlage. Illus- tration. No. of Section. Syncytial cells be- tween the blood spaces. — Syncytial cells not so num- erous. — 134-136. The vessels pene- trate the glands. — — — i 37-' 39- The endothelium of the vessels contain large nuclei, parall lie directly on the v ;1 with these a few essels. — — 140. Numerous syncytial cells in the sur- rounding of the- capillaries. — — — 141. Greatly dilated. Four large glands pass through the ovular elevation but much more distinctly visible tl b.) elongated; c. 2 In the center of the mound many syncytial cells and accumulation of leucocytes. lan in 132. a.) greatly coiled; nd d.) with distinct openings. Fig. 25. 142 and 143. Confluent blood spaces in the cen- ter of ovular ele- vation. Gland spaces and mouths. A few syncytial cells and ac- cumulation of leucocytes in the surrounding of the cen- tral blood spaces.' — 144 and 145. Dilated confluent blood capillaries in the ovular eleva- tion. Glands dilated. Between them accumulation of leucocytes. — — 147. Capillaries greatly dilated. In the surrounding ol al cells are present. Likewise the glands. both many decidu- — — 151. A few very large syncytial cells with highly stained in the more centr spaces. nuclei are still found ally located blood — — 152. Central blood spaces and with these communicat- ing capillaries. — — — I51 and 155- 32 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. No. of Section. Mu Without fibrin cover. cous membrane elevation har With fibrin cover. soring the ovum. Epithelium above. Epithelium beneath? 156. Fibrin with large ovular elevation. nuclei passing through the — — ,58. In the ovular elevaiton only the borders of the more centrally located blood spaces can be seen. — — 1 60. Ovular elevation supplied with enormous capil- laries. Uterine sur- face epitheli- um present. — 33 CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTION 1-160. Blood vessels. Glands. Eianlage. Illus- tration. • No. of Section. To the left and 157: Centrally large blood spaces. right glandular spaces partly filled with blood. 156. — — — ,58. Detached capil- laries. Numerous glands. — — 1 60. GENERAL CONSIDERATION OF THE RECONSTRUCTION OF THE OVUM FROM SECTIONS 1 TO 160. It may here be stated that all the microscopic sections have been embedded with the summit of the elevation produced by the ovum, pointing to the right, as in Fig. 2 ; thus the entrance into the fur- row formed by the mucous membrane, also opens to the right. In this manner the meaning of the constantly recurring terms "right" and "left" in the description of the sections, is obvious. I. THE MUCOUS MEMBRANE ELEVATION WHICH HAR- BORS THE OVUM, AND THE DECIDUA VERA. The mucosa, which lines the corpus uteri, is about 5 mm. thick in the fundus and anterior wall but about 8 mm. thick in the middle of the posterior wall. As previously mentioned, numerous deep and irregular furrows divide the mucous membrane into a number of fields. Toward the internal os (Plate I Fig. 1. o. i.) the mucosa suddenly becomes thinner and assumes the charac- teristic appearance of the plicae palmatae. It is here only 2 to 4 mm. thick. Since, as is well known, the mucous membrane of the uterus has no submucosa, a sharp line divides it from the un- derlying muscularis (Fig. 2, g.). Any thin section passing through both mucosa and muscularis, if held to the light, will distinctly show this sharp division both in the pregnant and the non-pregnant uterus. Nevertheless the connection between the mucosa and the underlying muscularis is a very firm one. The blind ends of the uterine glands are fastened by means of a very fine meshed connective tissue near the funnel shaped cavities and holes formed by the muscular fibres which are visible imme- diately below the mucosa, both in transverse and oblique sec- tions. In Fig. 1 the somewhat lighter spot, marked "Ovum," indi- cates the seat of implantation of the small ovum. It lies in a slightly protruding elevation of the mucosa ("Schleimhauthue- gel") nearer its slope, which gradually loses itself in a broad and rather deep furrow, (vide Fig. 2, a — 2. c. Fig. 23, sections 94 to 96.) In about the first ten sections this little hill appears as a hori- zontal fold of the mucosa with a sharp edge (Fig. 2. a. h.) which, as can be seen under the microscope, begins with a blunt 34 THE MUCOUS MEMBRANE ELEVATION. 35 extremity and has a gland passing through its entire length. This gland in its middle portion is dilated and folded and lined in its entirety with perfectly preserved cuboidal epithelium. Gradually this hill like elevation becomes more rounded (Fig. 2. b. h.) with a sharp groove on its right side. This shape is maintained through almost all of the sections until section 160 is reached, where it takes on a more club shaped appearance. The furrow to its right has become somewhat shallower and now runs perpendicular. We might be led to believe that this elevation was brought about by the embedding of the ovum, but the further examination of the specimen will show that the mound is only the marginal elevation of a mucous membrane field, lying just above a groove, through which the ovum has bored its way. This ovum, like the ovule of Peters, in all probability has en- tirely sunk into the mucous membrane, so that we also find in this case the ovular chamber completely surrounded by a de- cidua vera which extends up into the cap which covers the top of the ovum and protrudes into the uterine cavity. Besides this decidual tissue the cap contains the fibrinous cover consisting of two layers or two flat portions, while in Peters' case the clos- ure of the small opening on the top is formed by the fibrin lid alone, in this case the nidus of the ovum represents a com- pletely closed cavity which on its top carries the fibrinous cover. In investigating the histologic structure of this mucous mem- brane elevation our attention is at once drawn to the decidual tissue, the glands and the blood vessels, the ovular chamber and its fibrin cover. Since the two last named structures will be con- sidered in the next chapter, the enveloping tissue alone shall here be described. It is probably unnecessary to state that the younger the ovum, the better will be the opportunity of studying the origin of cer- tain structures such as the decidual cells, the syncytium, the inter- villous spaces, etc. If any doubt has still existed concerning the fact that the de- cidual cells are nothing else but hypertrophied connective tissue cells of the uterine muscosa and have nothing to do with the leucocytes, this doubt is now dispelled by this specimen. The mucous membrane enveloping the ovum is swollen and appears edematous. Large connective tissue cells with long pro- cesses form a delicate network. These cells contain large nuclei which in some cases completely fill the cell body. Some cells have two nuclei, and like Peters (1. c. page 15.), I was able to observe signs of karyokinesis in them. 36 THE MUCOUS MEMBRANE ELEVATION. In the vicinity of the capillaries and larger blood vessels, which are enormously dilated and in some places ruptured, we find many red blood corpuscles lying between the decidual cells. In this way the somewhat exaggerated histologic picture of hyperemia and actual suffusion of the mucous membrane (com- pare Fig. 25. Section 142) is formed, not unlike that described as occurring during menstruation, by the author1, later by.Geb- hard2, and recently by Sellheim.3 Between the blood vessels and glands the decidual tissue is distributed partly in fine and coarse bands, partly in form of an outstretched network and there is as yet no distinction possible between a decidua compacta and decidua spongiosa, since we find thick compact layers and broad bands of decidual tissue in the superficial as well as the deeper layers of the mucosa. Noteworthy is the wealth of glands and their course. In the sections on either side of the ovum (Sections 1 to 30 and 120 to 160) some of the glands can be followed in their entire length up to their entrance into the uterine cavity (Fig. 3, Section 4. Fig 25, Section 142). At the opening and in the middle they are often greatly dilated. Here their walls are folded, forming larger and smaller waves which like papillae protrude into glan- dular lumen and suggest the picture of a beginning adenoma In the deeper portions the glands are lined with a perfectly pre- served cylindrical epithelium which however becomes more dis- tinctly cuboidal the closer the glands approach the base of the peripheral wall of the ovular chamber. Since the latter is made up of blood spaces, as will be dem- onstrated later, the surrounding decidual tissue also is 'infiltrated with blood, as can be seen in Fig. 25, Section 142 (Plate XV bl.). As a result of this mucosa hemorrhage the glands in the imme- diate vicinity of the ovum also are filled with red blood cells and are in a state of partial dissolution exactly like during menstrua- tion.* The epithelium loosens from the glandular walls and disappears among the blood corpuscles. The delicate connec- tive tissue of the gland wall becomes loosened -and is dissolved; the further the ovular envelope moves toward the periphery, the more the glands become displaced. Their outer walls are flat- tened, their inner walls dissolved. Certain sections (37 to 105) show this process very plainly. It is best observed by following the three longest. The one in shape of an arch, reaches the ovum and partly encircles it, the second passes to the right, the 1 Leopold, Studien ueber die LTterus Schleimhaut (Archiv. f. Gynaek Bd. XI). 2 Gebhard. — Pathol. der Weibl. Geschlechtsorgane. 3. Sellheim-Nagel. Handbuch der Phy«iol. des Menschen, II 1, pages 96 to 98. Figs. 38-41. 4. Nagel. 1. o. Fig. 41. THE MUCOUS MEMBRANE ELEVATION. 37 middle one ends blindly near the ovum and as its cavity expands, gradually disappears. The Figs. 14 (Plate VIII) and 23 (Plate XIII) show espe- cially the arches formed by the left and right glands. In Fig. 22 (Plate XII) we see only a trace of the end of the middle gland, whereas in Fig. 24 (Plate XIV) the section 165, which lies further away from the ovum proper, again shows the end of the middle gland, which is dilated and filled with blood, (dr.) From this can be seen that the glands are considerably dilated and hypertrophied. The "Eianlage" acts as a foreign body and presses the glands toward the wall. The "Eianlage" furthermore, together with the free extravasated red blood, destroys and dis- solves glands and thus helps to form the intercommunicating blood spaces of which we will presently speak. None of the sec- tions furnished any proof for the assumption that the glands open directly into the ovular chamber, or that the ovum entered the mucosa through the mouth of a dilated gland. No signs were found of any well preserved glandular epithelium or even rests of such lining this cavity. This is furthermore made improbable since, as we have seen before, the glands in their entirety, includ- ing the walls and epithelium in the immediate vicinity of the . ovum, are dissolved as the result of its growth. The mucous membrane elevation and all the adjoining tissue down to the muscularis, is very vascular. The structure and course of the blood vessels during the first weeks of pregnancy have been carefully described in a number of excellent works and we refer to them for further information. Here only those facts shall be emphasized which seem most important in connec- tion with the very earliest stage of pregnancy. Since they are dealt with only in the work of Peters, a confirmation or further elaboration of his contribution would seem very desirable. In the deeper portions of the mucosa, especially in the thicker layer of the decidual trabeculae, one still meets with little arteries twisted like cork screws. As a rule they are found cut either transversely or lengthwise, the latter often accompanying the glands for a long distance. On cross section the capillaries show around their endothelial lining a second and sometimes a third delicate ring of endothelium. The closer the ovum is approached, the greater becomes the number of capillaries and the greater is their distention and the extravasation of red blood cells into the surrounding tissue. .If the delicate wavy walls of these distended capillaries are carefully examined, it will be seen that at certain places there are defective areas or even tears, through which the 38 THE MUCOUS MEMBRANE ELEVATION. erythrocytes escape into the adjoining tissue. They loosen the glands and detach the swoolen epithelium which now lies crumbled in the gland duct. In this way a coalescence of glands and capillaries is effected which in the neighborhood of the ovum results in the continuous formation of new inter- communicating blood spaces. If Figs. 7 and 8 ('Plate IV) marked "c," are carefully studied, this process can be better understood than describing the same. Figure 14 (Plate VIII) is still better, in which c and c± indicate the adjoining cavities filled with blood. The confluent blood spaces are best seen in Fig. 22 (Plate XII) where "c" shows fine septa as the remains of the tissue which at first separated the glands from the capillaries. As the "Eianlage" grows these septa become still thinner and are finally completely dissolved, so that at "c" the blood spaces are in direct communication with their neighbors cl and c2, and the latter again with the ovular chamber and its blood spaces. Attention is here called to the fact (which later on will be dealt with in detail), that the trophoblast processes have anchored themselves to the walls of these spaces at cx and c2. Thus it is self-evident that in the entire periphery of the ovum these trophablast pro- cesses are surrounded and nourished by connecting blood spaces. These conditions are seen more distinctly in section 94 (Fig. 23, Plate XIII). At "c" a broad blood space runs almost parallel with the glands to the ovular chamber. At cl another one passes from the left inward and breaks up into several blood spaces which communicate with the ovular chamber. It is best seen at c2, where a dilated capillary, running to the left and upwards, like through a slit, appears in the cavity. A striking similary is obvious, if we compare these pictures with those in my atlas ("Uterus und Kind" plate VI) illustrat- ing injected intervillous spaces in the fifth month of pregnancy, which communicate with vessels of the serotina. It seems justifiable to deduce from Figs. 22 and 23, that al- ready in the first days of pregnancy, as described by Peters and myself, the capillaries, through their dilatation, their breaking up into the surrounding tissue and their dissolution into enor- mous blood spaces which communicate with the ovular chamber, form the first rudiments of the intervillous spaces. How do these statements compare with those of Peters, Graf von Spec (1. c. pg. 2.) and the various researches made on ani- mals, as compiled by Pfannenstiel1? In this early stage Peters has also observed decidual cells. He could not find a sharp di- vision in the mucosa between a compacta and spongiosa. 1 Winckel. Handbuch der Geburtshilfe. Bd. I. 1, pg. 194. THE MUCOUS MEMBRANE ELEVATION. 39 The mucous membrane elevation in which his ovum lies, pro- trudes but slightly and still has a superficial epithelium covering its margin. The glands are greatly dilated, lie around the ovum meridionally and also have no communication with the ovular chamber, the latter pressing them aside. In his sections also vari- ous uterine glands (Plate I) are seen filled with blood, the sur- rounding of the ovum containing an enormous wealth of greatly dilated capillaries which in part are changed .into wide blood spaces exactly as in my specimen. In his Plate I, a large blood space is seen to the right and below, like an extravasation sur- rounding almost half the periphery of the ovum, communicating freely with those blood lacunae in which the trophoblastic pro- cesses are directly immersed. Although the similarity between Peters' and my specimen is striking, still attention must be called to certain apparently ex- isting differences. In Peters' specimen the trophoblast every- where lies in direct contact with the inner wall of the envelope of the ovum and an embryonic rudiment is plainly visible. In my specimen, on the other hand, the trophoblast has not as yet everywhere reached the inner wall. It still partly floats, in the blood which fills the ovular chamber. In spite of repeated and careful examinations no trace of an embryonic formation could be detected. Whether this floating of the trophoblast in the blood of the ovular chamber and the absence of an embryonic "Anlage" is pos- sibly only due to a pathological extravasation of blood between the ectoblast and mesoderm, is still a question which, must be decided later. This difference, which in this connection is simply registered, is striking and might warrant the question, whether the ovum in my specimen is not possibly a few hours younger than that of Peters, and, whether within the next one-half day the junction between the trophoblast and the inner wall of the ovular envelope would not have been completed. This, however, must 'remain a mere assumption until other specimens of such an early stage have been found. At any rate the same vascularity which is observed in our two specimens, is also found in the uteri of animals. "The changes in the maternal mucosa surrounding the ovum, in the various mammalia, are differently described. A formation of new ves- sels in the immediate neighborhood of the chorion, often to a great extent, is regularly found. In advanced stages noticeable vascular changes also occur in the deeper layers of the mucous membrane1." "Very important are the results of researches made on animals 1 Pfannenstiel in Winekel 1. c. pg. 198. 40 THE MUCOUS MEMBRANE ELEVATION. regarding the first relation between the surface of the ovum and the vascular system of the maternal mucosa. This relation is established very early, both in the insectivora and the rodents. The ectoblast thickens at the placental site by the formation of numerous layers and lacunae soon form which become filled with maternal blood. The manner in which the blood gains access to these spaces is not sufficiently understood, but it is certain that the new formation of maternal blood vessels near the ectoblast is enormous and that from them the ectoblast lacunae receive their blood supply." "The maternal blood from the very beginning remains in a closed channel and in regular circulation. Frommel has demon- stated the same conditions in the bat. In the carnivora, e. g., the cat, these maternal vessel walls are also preserved in the pla- centa. The significance of this fact for human placentation is evident. In animals the "intervillous" spaces appear very early; they are filled with blood from the very beginning and are in con- stant and lasting communication with the maternal blood vessels. These same conditions no doubt also prevail in the human." From the above description this presumption is proved a cer- tainty, even for the earlier stages of the human ovum. ' The vascularity of the mucosa in my specimen, in its relation to menstrual conditions, is still another subject worthy of consideration in this chaper .Peters estimates the age of his ovum as from 3 to 4 days by assuming a relation between it and the menstruation which for the first time had just failed to appear. He bases his assump- tion on the history of the case and on the histological condition of the decidua, which, "in every respect resembles the description given of decidua menstrualis immediately preceding menstrua- tion." 2 From the history Peters endeavors to show that on the day of her suicide (October 1st) the pregnant woman was about to menstruate. From the state of development of the Eianlage and the entire ovum itself, no other conclusion could be drawn, save that this represented the impregnated ovum of the expected men- struation. Based on these facts he estimated the age of the ovum as possibly three to four days. Although I agree with Peters in regard to the manstruation- like appearance of the mucosa, I cannot coincide with him in his calculations from the history of the case. We read' on page 3 of Peters' work that the woman had her last normal menstruation on September 1st, 1895. At the end of September (on September 28th, according to the normal type, 1 Pfannenstiel 1. c. pg. 200. 2 Peters 1. c. pg. 16. ' THE .MUCOUS MEMBRANE ELEVATION. 41 and no statement to the contrary is made) the menses should have reappeared. They did not, however, return at the ex- pected time, and the woman, fearing pregnancy, committed sui- cide on October 1st. This would be 3 to 4 days after the ex- pected appearance of the menses. Or, if we assume from certain observations that the ovule escapes from the matured follicle about two days before menstruation, the suicide was committed five to six days after the expulsion of the ovum from the follicle and the impregnated ovule presumably would then be five to six days old. Probably it is only a lapsus calami when Peters on page 16 states, that the woman was about to menstruate on the day of the suicide ; he should have said that her death oc- curred about three to four days after the expected menstruation, which for the first time had failed to appear. Whether or not this ovum be four or six days old does, how- ever, not in the least diminish the value of this specimen, for by its examination Peters has certainly succeeded in throwing new light on the embedding theory of the human ovum. An accurate idea of the respective age of such ova we shall have only after more such small ova have been described, of cases in which absolutely reliable histories have been obtained. At present one seems justified in associating his specimen with the first missing menstruation. The same surely holds true of my specimen, even without a history, since there is not even a suggestion of a embryonic rudiment, of an amnion, etc., present, as was found .in 'Peters' ovum. I am, however, willing to refrain from making any estimate of the age of my ovum. Later investigators who may have the good fortune to work with reliable specimens of cases in which accurate histories are obtainable, may then determine the age of my specimen. Of a very similar character is also the ovum demonstrated by Graf von Spec in Kiel in 1905. It also comes from a woman who committed suicide by taking oxalic acid. "The mucosa of the uterine body, as is characteristic for pregnancy, was divided into irregular areas by deep furrows. One field immediately in front of the right tubal opening, on the anterior wall, was more prominent and had an umbilication with a marked discoloration. This aroused the suspicion of being the nidus of the ovum. His- tologic sections made of this portion of the mucosa proved to be very satisfactory for examination and on demonstration through the epidiascope showed the following condition : Taking up about two-thirds of the free surface of this prom- 42 THE EMBEDDING OF THE OVUM. inent mucosa area, in a cavity of the interglandular connective tissue of the mucosa, an ovum 1.5 x 2.5 mm. was situated. It had but few villi and contained an embryo in a very rudimentary stage. Between the surfaces of the chorion and uterine tissue, here and there, small quantities of blood could be seen which es- caped from ruptured vessels. The walls of the ovular chamber •were entirely made up of elements of the interglandular connec- tive tissue. All the glands opened into the uterine cavity, none into the ovum chamber. Like the ovum of Peters, the serotina, i. e., the mucosa, between the ovum and uterine muscularis, con- tained, within greatly dilated endothelial tubes, large blood clots apparently formed still during life. This blood served a double purpose, furnishing nutriment to the ovum and protecting the deeper portions of the mucosa against the corrosive action of the ovum. That portion of the envelope of the ovum which separ- ates the cavum of the uterus from that of the ovum, consisted of a thicker or thinner layer of interglandular connective tissue cov- ered towards the uterine lumen by a single stratum of epi- thelium." Thus it can be seen that also in this specimen the ovular en- velope is formed by decidual tissue, none of the uterine glands open into it, and near the ovum, especially in the serotina, large blood masses lie in immensely dilated endothelial tubes. II. THE EMBEDDING OF THE OVUM. THE CAPSULARIS. THE FIBRIN COVER ("GEWEBSPILZ OF PETERS"). Since it has been established by Graf von Spec for the guinea pig and by Peters for the human being, that the ovule bores its way through the surface of the mucosa, it has become the duty of the later investigators to determine whether this is the only mode of nidation or whether not occasionally a circumvallation occurs arising from the mucosa surrounding the ovum. Pfannenstiel 1. c. page 194, is correct in saying: "The ovum de- scribed by Peters is already completely or almost completely en- veloped by the mucous membrane. In spite of the great value of this specimen, in spite of the fact that it has revolutionized our views concerning ovular nidation, we should not forget that this is the only specimen extant of this early stage of development and it would seem advisable not to go too far in its interpretation." THE EMBEDDING OF THE OVUM. 43 Which, then, are the similarities and which the differences be- tween mine and 'Peters' specimen ? First of all, it is to be noted that the mucosa elevation on the sides of the ovule almost up to the fibrin cover, is still covered with a surface epithelium (Fig. 3. e. Plate II). Close to the fibrin cover the epithelium becomes irregular, is partly swollen and partly detached. In some, sections (Figs. 7 & 9, e,e, 'Plates IV & V) it extends like in Peters' specimen (Plate I U.E.) under the fibrin cover, as a narrow band. At the^ slope towards the furrow (F) it is practically absent. Special stress is to be laid on the fact that under the center of the fibrin cover where it lies closest to the summit of the ovum, no more regular surface epithelium is met with. Like- wise nowhere within the ovular chamber can even a trace of epithelial lining be found which connects with the surface epi- thelium. One peculiar condition which appears only in the sections 15-19 (Figs. 5 & 6 Plate III) must be described. in detail. To the right, below the center of the fibrin cover, a depression (e. s.) is noticed which is lined by a few cuboidal cells (Fig. 5) whose resemblance to epithelial cells cannot be denied. Among them, however, are a few broader cell bodies with large nuclei which are not unlike syncytial cells. This supposition is strengthened by the fact that with high magnification one can see a few large syncytial cells extending from the nearest trophoblast plugs to- wards the depression e. s. (More details will be given in a later description of the trophoblast, Fig. 10.) This funnel shaped depression is still distinctly visible in Fig. 6 at e. s. Here, however, it is filled with red blood cells which have escaped from the ovum chamber and in their- further course cannot be differentiated from the blood cells which infiltrate the structureless fibrin mass. (Fi.) This funnel shaped depression seems worthy of special note and probably deserves to be particularly considered in all fu-" ture investigations. It is certainly the only visible and partly preserved connection between the ovular chamber and the uter- ine cavity. What will be its significance? It might be regarded as the remains of a glandular orifice, yet much speaks against this. First of all there is no gland opening anywhere within a wide area of this spot, especially outside of the fibrin cover. Naturally so, since the glands have been displaced by the ovum and lie more meridionally. We have already shown that the glands do not take any direct part in the formation of that cavity which 44 THE EMBEDDING OF THE OVUM. harbors the ovum and that this chamber nowhere in its interior carries a lining of uterine epithelium. If this funnel was ac- tually a gland orifice the good preservation of its cells would be striking in contrast to the glandular openings still visible to the sides of the ovum, since their epithelial cover consists almost only of swollen, detached and liquified cells. The question suggests' itself, however, whether this funnel shaped depression does not indicate the site where the ovum has entered the mucosa. My ovum does not show any "Anlage" of an embryo and therefore must be younger than that of Peters, in which an amniotic cavity with an exocoelum is distinctly vis- ible. The assumption may be justified that my ovum has just ac- complished its nidation and is about to become sufficiently an- chored to the ovular envelope by sending out trophoblastic pro- cesses. The fact that this place at e. s. represents the only visible connection, obviously leads to the question, whether or not the ovum has possibly here entered the mucosa. This place is certainly about to become obliterated by the encroachment of decidual cells from both sides, but there is still a relation extant between the interior and exterior. At a place within the blood filled space of the ovular chamber lying closest to the depression e. s. (in Fig. 6), an escape of red blood cells can be followed, one sees how they collect at e. s. and from here permeate the fibrinous cover. Thus one seems justified in assuming that also the fibrin- ous cover has originated here, that it serves more or less as a lid and that it is supplied with red blood cells until the envelope completely surrounds the ovum. Before the structure and development of this fibrinous cover is considered in detail, the process of embedding of the ovum, and the ovular chamber must be considered. In all sections (Figs. 14, 22 & 23, Plate VIII, XII & XIII) the decidua com- pletely surrounding the ovum, shows the indentical histological structure. Although varying in thickness at different places, especially at the summit of the ovum and at both sides of the mucosa elevation, the decidua everywhere consists of thin wavy fibres containing larger and smaller decidua cells, numerous cap- illaries and a large number of extravasated red blood cells. One can therefore not say that the mucosa has reflected itself from the two sides over the ovum, lying in its chamber, nor can as- sert, that a scar can be seen on the summit of the ovular ele- vation. Everything points rather to the fact, which has been proved by Peters, that the ovum has burrowed its way into the mucosa, in our specimen somewhat asymmetrically in a mucosa eleva- THE EMBEDDING OF THE OVUM. 45 tion. The point of entrance in our case has become almost com- pletely obliterated, but there still persists a narrow channel from which some blood oozes, the latter accumulates at the summit of the ovum and becomes transformed into the fibrinous cover. It Peters' specimen the connective tissue does not as yet form so complete an envelope as in mine, in which the ovum has possibly already penetrated to a greater depth. In his case, there- fore, the opening still existing in the decidual envelope is covered by a broad layer of fibrin partially organized. It is called by him the "Gewebspilz." The trophoblastic processes with their syn- cytial excrescences are directly attached to it Concerning the clos.ure of the defect through which the ovum has penetrated, 'Pfannenstiel (1. c. page 220) has expressed him- self very carefully. Since at that time Peters' specimen was the only one known, he considered the process of closure as uncer- tain. Descriptions of very young ova as given by Peters, Graf von Spec, Heukelom, Leopold and Keibel had stated "that at the point of closure not a distinct decidual tissue but a scar tissue is found, consisting chiefly of fibrin and showing an absence of blood ves- sels, also he himself was able to confirm the presence of this fibrinous scar tissue, he would not consider this question defin- itely settled since the formation of fibrin within the decidual envelope of the ovum is very common and often can be traced to an entirely different cause. It would seem possible that the final closure of the decidual capsule around the ovum is accom- plished by a firm coalescence of the vascular connective tissue which proliferates from opposite sides. At this place, which is the most poorly nourished portion of the reflexa, soon after- wards signs of degeneration would appear especially so in ova which are more superficially embedded. The blood plug of Peters thus might possibly be considered an abnormal condition.'' The assumption of Pfannenstiel that the ovum has an entirely decidual envelope is confirmed by my case, with the exception of that narrow opening at e. s. As mentioned before, it is caused by a deeper implantation of the ovum. Nevertheless, there is in our case, like in that of Peters, a large and very broad fibrinous cover lying over the top of the ovum, so that such a cover must form even in case of complete decidual inclusion. In any explanation, however, of the origin of this fibrinous cover one must consider this narrow opening through which the ovum sank (e. s. Fig. 5 & 6) and whence that tiny amount of blood has oozed to the surface and there coagulated. In order to obtain a clear conception of this fibrinous lid one must first of all gain a precise idea of its form, length, width and 46 THE EMBEDDING OF THE OVUM. structure. It can be seen in the microscopic sections from 10 to 70, then again from 75 to 103 and a trace of it finally in section 119. The entire 160 microscopic sections are embedded so that the slope of the mucosa elevation with the furrow (F) lies to the right of the specimen and all illustrations follow the same rule. It will thus be perfectly plain, if in describing this fibrinous cover the term "left," applies to the direction toward the uterine fundus, the term "right," toward the slope of the mucosa ele- vation and the furrow (F). If for the purpose of reconstruction, the various sections are placed together, one receives the impression, in a view from above, that two minute drops of coagulated blood lie on the mu- cosa elevation near its slope. The larger drop lies more towards the right edge of the uterus, the smaller and flatter one to the left. Still farther to the left in section 119 a trace of a coagu- lated mass can be seen. All sections through the larger drop show its right half con- siderably thicker and more voluminous than the left. On the sec- tions through the center, the fibrin appears in rolled up waves like a congealing substance. (Figs. 7, 9, 11, 14, 15. Plates IV, V, VII. VIII. IX.) In explaining this condition one must con- sider that this thicker portion is situated exactly over the fine fissure (e. s.) through which blood is still oozing from the ovular chamber. On the other hand one must keep in mind that the escaping drop, both in the lying or standing position of the woman, must gravitate downwards, i. e., in the direction of the slope of the mucosa elevation. The size and structure of the fibrinous cover as well as its re- lation to the ovular chamber can be best understood from a study of some of the illustrations. In section 10 (Fig. 4, Plate II) the cover suddenly appears. It has the shape of an oblong cylinder, somewhat thicker to the right, whose left lower edge is intimately connected with the decidual envelope of the ovum. From the left some surface epithelial cells, already irregular, penetrate under the edge of the cover (e). On its surface lies a band varying in thickness that possibly consists of surface epi- thelia of the mucosa, which, however, are not discernable as such. The cover itself consists of a mass of fibrin in which here and there white and red blood corpuscles are met with. Almost identical conditions are found in sections 15 and 19 (Figs. 5 and 6 Plate III), only that in Fig. 5, in the band on the surface, a few cuboidal epithelia can be seen, whose origin T failed to determine. THE EMBEDDING OF' THE OVUM. 47 In sections 22 (Fig. 7) and 27 (Fig. 8 'Plate IV) the fibrinous cover appears in a considerably changed form. Like a catter- pillar with a large head, it lies on the ovular envelope, which has become thinner. Under its right and left edge (Fig. 7) traces of surface epithelium are seen. Its superficial portion contains a few white blood cells, in its interior a delicate network of fibres. Most conspicuous, however, is the folded appearance of the coagulated .mass to the right (Fig. 8 fi) which depresses the ovular envelope. These conditions are most plainly visible in Fig. 9 (Plate V) and Fig. 11 (Plate VII). In the latter, representing section 30, at fi., fibrinous masses, like frozen waves, are heaped one upon the other, causing a deep indentation of the walls of the ovular chamber. In Fig. 13 the fibrinous masses contain a large amount of white blood cells, still more of them in Figs. 16 and 17, while in Fig. 15 the clubbed end of the cover is the thickest. Here over the depressed portion of the ovular envelope the fibrinous masses are arranged exactly like in a corpus luteum in the stage of organization. Gradually the arrangement and signs of an organization make their appearance in the fibrin cover in form of connective tissue fibrils. Thus a sort of new formed protective layer develops over a portion of the ovular envelope. This portion in itself is very thin, but is further weakened by trophoblastic processes which, as will be described later, for the purpose of fixing the Eianlage, have penetrated into the summit of the ovular cham- ber. (Compare Peters.) The formation of a protective cover for which the escaping blood droplets have been utilized, must be regarded, as has al- ready been emphasized by Peters, an exceedingly important process and a wise provision of nature. If Figs. 18 and 19 (sections 68-69) are compared it will be seen that the left portion of the fibrinous band has undergone a certain organization and reenforces the ovular envelope. The right clubbed shaped end is a mass of twisted fibrils which has gradually decreased in size and like a button (Fig. 19 kn) lies in a depression. Since with section 70 the larger of the coagulated drops disap- pears, it must be assumed that the surface between sections 70 and 75 (Figs. 19 and 20 Plate XI) is free of any fresh deposit of fibrin, carries, however, the continuation of the organized portion. In section 75 (Fig. 20) suddenly a new fibrinous layer ap- pears. To the left of the mass, which is in a state of organiza- 48 THE EMBEDDING OF THE OVUM. tion, lies a band varying in thickness which resembles the rests of surface epithelia and extends upwards along the edge of this new fibrinous cover, thus the observation described above is prac- tically repeated. Again the cover becomes oblong but in this instance is thicker in the middle portion, but in general does not attain the length or thickness of the fibrinous cover previously described. There are a few white blood cells in its middle part. With section 105 this fibrin band has again disappeared, here (Fig. 24 Plate XIV) the ovular chamber being cut more later- ally shows a thicker wall while in the preceding sections the fibrinous cover seemed to play the role of a reenforcement for the ovular chamber and of a protective layer, as was clearly shown in the pictures of the first mentioned larger fibrinous mass. Concerning a fibrinous cover (Gewebspilz) in the ovules of Graf v. Spec (Kiel 1905) and of Beneke, we find the following references : Van Spec says on pg. 422 : "At the site of the fun- nel shaped depression the uterine tissue shows a defect which must be regarded the gate through which the ovum entered the endometrium during the process of implantation. This open- ing is sealed by a flat blood coagulum (fibrin, containing leuco- cytes and red blood cells). Thus the conditions are very sim- ilar to those described by Peters. The opening which appears with a diameter of not more than 0.8 mm., possibly is larger than at first produced by the ovum. This increase may be due to the stretching and* growth, possibly also to a histolytic action of the ovular wall." Beneke reports on page 772: "The tissue plug (Gewebs- pfropf) which closes and fills the defect in the reflexa in general corresponds in its histologic structure to that described by Peters. It contains blood, fibrin, leucocytes, etc." After this description one's attention obviously is again drawn to the question of the similarities and discrepancies between mine and Peters' ovum. Up to this point both specimens are identical in all essential features. In both we see the decidua vera in a condition of edematous infiltration. In both the ovule lies in a swollen mucosa near a furrow, in both instances the ovule has penetrated into the mu- cosa at a place deprived of epithelium and has pushed aside the tissue and the glands so that the latter follow a meridional, curved course. Over the top of the ovum the edges of the mu- cosa have approached each other in an attempt to close the ovular chamber completely. This process has progressed further in mine than in 'Peters' specimen. In both cases on the top of THE EMBEDDING OF THE OVUM. 49 the arch, where the ovum has entered, a blood coagulum is found serving as a protective covering, which in Peters' specimen re- sembles a mushroom, in mine a caterpillar with a large head. This variation in shape so well pronounced in all my sections, calls for a more appropriate name. Peters' term "Gewebspilz" certainly cannot be applied to my specimen. With the idea that such an expression should be applicable to all later cases it seemed most natural to select the term "fibrinous cover" (Fibrin decke). Whatever its name may be, however, the fact remains that in these two youngest human ova it was present, large and well developed. This explains the peculiar rests of fibrin found on the top of the ovum in older specimens, as, e. g., described in my atlas (Uterus und Kind, Plate I). As first shown by Peters, our specimen also proves that the old circumvallation theory of the formation of the reflexa is in- correct, but still a reflexa is present. If one drops a stone into the water the latter closes over it and if an earth worm bur- rows itself into the ground, the hole made by it will again grad- ually be filled with the loosened soil. 'The rapidity with which it becomes closed will depend upon the character and structure of the soil. It seems permissible to call rcflc.va in Peters' and my speci- men, those decidual arches which approach each other approxi- mately over the center of the ovum. One must, however, keep in mind that these arches have not newly formed and closed over the ovum, but that as a matter of fact, they have existed from the first beginning and that through them the minute ovule has burrowed its way. The arches become higher the more the ovum grows. It is obvious that the opening between the arches, i. e., the passageway of the ovum, finally again becomes closed by either a fibrinous plug or a fibrinous band. In the following it will be shown that the great similarity ex- isting between the microscopic pictures of Peters' and my speci- men, leads to a like interpretation of the findings. Peters (pg. 28) emphasizes that his ovum has become im- planted in the swollen mucosa near a furrow, the same has oc- curred in my case. Since the uterine mucosa prepared to receive the ovum is traversed by numerous deep furrows, he thinks it might possibly happen "that the minute human ovule could be caught in such a groove and then actually could become em- bedded (exactly like the ovum of the erinaceus) if the edges of the furrow coalesced and finally closed." "In such an in- stance, however, the ovum would be completely encircled by a 50 THE EMBEDDING OF THE OVUM. uterine epithelium and surely one or the other gland would be found opening into the ovum." I agree, that an ovule in this way might enter such a furrow and be caught, but still it could there sink into the mucosa, but even if it should further develop while wedged in this groove, I cannot see the necessity that it should remain surrounded by uterine epithelium and that as Peters explains this protecting maternal layer should then be secondarily destroyed by the pro- liferation of the fetal trophoblast. In the premenstrual stage the epithelium of the uterine mu- cosa is loosened, swollen and rendered detachable by small sub- epithelial hemorrhages to such an extent that an intact, firmly adherent and continuous epithelial covering in such a furrow could not be expected and hardly ever is found. Therefore, from an anatomic histologic point of view, I cannot object against the possibility of ovular implantation in a furrow and would not regard it as surprising if a gland would run up to the ovular chamber (compare Fig. 24 drt Plate XIV) and appar- ently open into it. Such facts do not alter my present assump- tion that the ovum passing through the superficial epithelium and pushing the glands aside, burrows itself into the mucosa. In my opinion, it matters not where the ovum has become attached and where embedded, whether on the summit of a cotyledon (as in 'Peters' case) or near the slope of an elevation, as in my specimen, or in a furrow, the ovule will everywhere be the source of considerable irritation and a pronounced reaction in the adjoining tissues. This reaction has been so well described by Peters that I give my own opinion by simply citing his own words (pg. 29) : "One seems justified in assuming that at the site of implantation, either through mechanical irritation or by a provision of nature, the tissues become highly congested, plasma (edema) and corpuscular elements of the blood extravasate, the preformed endothelial tubules dilate, the mucosa swells and thickens. It still remains undecided in which manner the blood elements are set free, whether as a result of an increased pres- sure within the vessel or through rhexis or a free diapedesis, or possibly the capillary vessels have been opened by the epiblast, which has begun to proliferate as soon as it came in contact with the maternal tissues. The fact that the fibrinous plug which lies on the summit of the ovum pointing into the uterine lumen, con- sists of blood elements, almost forces us to assume that during the process of the embedding of the ovum into the edematous connective tissue stroma, the ovum, and its free surface towards the uterine cavity, is surmounted by a blood coagulum which pro- THE EIANLAGE AND THE OVULAR CHAMBER (EIKAMMER.) 51 tects it and possibly furnishes nutrition for that portion of the ovular surface which as yet has not established its connection with the maternal tissue." If we compare the histologic pictures of our specimen- with this description, the sections 15 to 19 call for special attention, because they plainly prove the minimal but quite noticeable es- cape of blood from the ovular chamber into the fibrinous cover. We have also seen how the left half of the fibrinous lid has be- come more and more organized and in this way reenforced the decidual envelope and how to the right the large head of the fibrinous band, which lies in an indentation of the ovular cham- ber, closes the opening of entrance. Still other similaraties can be detected. In Peters' ovum (Plate III, Fig. 4) there is also a lateral and central depression in the fibrin plug, so that the fetal ectoblast almost immediately touches it. On the other hand in his specimen the trophoblast processes also penetrate into the decidual layers over the sum- mit of the ovum, so that in some places they become extremely thin and appear worm eaten. Finally, it shall here be mentioned (Peters, pg. 44) that the envelope of the embryo of Graf v. Spec was surmounted by a flat blood coagulum. III. THE EIANLAGE AND THE OVULAR CHAMBER (EIKAMMER). \Vc have seen that the o.vule has burrowed itself, gradually pushing aside the decidual tissue. Some of the glands were dis- solved, others displaced. The blood vessels were in a state of ^narked congestion, multiplication and coalescence. This shows clearly how the ovular chamber, especially its summit, consists >/. 2. b. It Section, SO Section 700. Plate H. . 3. '• .•••• Fig. 4*. fi. - .- . -,. - - .:* /''if/. '). \ e» • I « • • * . <'-•. v • * ^^.;-- '•_ -.- • v \: , .i,V.. ,r»i :'••': \ *. |, / _ w W-3*. K*~ W1 '^^1H - 1~— I v; ' • • M* I Male V. ' V> " »•*.' »*;* ,• ' *. I ?.»»TV'«^ • * ',;• -„ ^•Kv'i'V - > .. -%.A ' . ; •/ ' • ' , ' • ' • ;: •; */' ».; B I Fi0.11. IMalc M. Fig.13. n .::-'• -••••; :: dr. s.b. Plate Vlll. x * ft. "• . • • • i '^.^•: v,:='" lith .Anst . Julius Kir, ! i IX. •* • -.>»' \ ,-''.' * •«/ : ' . *•• Y Fir]. Hi. • ~~' '~:> •*>>! .*'-'.fr- W«?^1PIPW '"""" \ ^^'M F19. Ekl... Plait- X. Fig. 19. Fig. 20. krv. s.b... Plate XI. . •Cj dr late Ml Fig 22 % */ J £•*'• •*•*. , '*, .»..-• /A- -'v \Jf»~* " : ( '"f/" i^; /*• "/ Fig $'• w ihJtfiC- dr "-'<\-. : . Plalr XIII. . «• , .• v •« !* ' 'f " i ^ %ufi£:""?^H l«'?%:'- " ;| " ^^'\;^V' :•; . ' 47 :x . '. ' -I'f V."v":: '>v: : '., ; ..••*.-- m;.y /••• • -'- litii -Anst. Juhus Klmkhardt.Leipag. tr. I-*'' ''/"' '-• >'.»• x ( PlaU- XVI /•>//. 27. « a *• sy. v». .• UNIVERSITY OF CALIFORNIA Medical Center Library THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW Books not returned on time are subject to fines according to the Library Lending Code. Books not in demand may be renewed if application is made before expiration of loan period. 10m-12,'54(9093s4)4128 1 oi ?r