UC-NRLF C E 7bS D1S QGICAL.4 WITH TEXT I'R'ICK SKVEN sniLIJX'J.-- ' >J) SIX Zooh dwot BIOLOGY LIBRARY BIOLOGICAL ATLAS A GUIDE TO THE PRACTICAL STUDY OF PLANTS AND ANIMALS Stoapteti to tfje requirements of tfje ILonion JSnibersitg, Science ano Slrt department, anb for use in Scfjools anfc Colleges WITH ACCOMPANYING TEXT CONTAINING ARRANGEMENT AND EXPLANATION, EQUIVALENT TERMS, GLOSSARY AND CLASSIFICATION 423 COLOURED FIGURES AND DIAGRAMS D. M'ALPINE, F.C.S. LECTURER ON BIOLOGY AND BOTANY, EDINBURGH, AND HONOURMAN OF THE SCIENCE AND ART DEPARTMENT; AUTHOR OF "SHORT NOTES FOR BIOLOGICAL STUDENTS," AND "A ZOOLOGICAL ATLAS " AND A. N. M'ALPINE, B.Sc. (Honours) LOND. LECTURER ON BOTANY, SCHOOL OF MEDICINE, EDINBURGH ; PROFESSOR OF BOTANY AND NATURAL HISTORY, NJSW VETERINARY COLLEGE, EDINBURGH, AND ASSOCIATE OF THE ROYAL COLLEGE OF SCIENCE FOR IRELAND FIFTH THOUSAND W. & A. K. JOHNSTON EDINBUEGH AND LONDON 1IDCCCLXXXI Q//3/7 BIOLOGY LIBRARY G L> PREFACE. IT is now generally recognised that a certain acquaintance with actual specimens is necessary for the proper understanding of Plants and Animals. By the practical study of representative forms, exemplifying the leading modifications of plant and animal life, the student obtains a basis of distinctly observed fact with which to compare other forms, and round which to cluster the infor- mation derived from books. The University of London has given practical shape to this idea by selecting a series of common types which " each candidate must be prepared to examine microscopically, to dissect and to describe." In this Atlas, which is intended to serve as a guide to, and not as a substitute for, practical work, drawings are given of the various points of importance exemplified by each of these types, to enable the student to make out the points for himself on the actual specimens. Experience both as students and teachers has taught us, that in this constant appeal to the object itself, the student is greatly assisted by clear and accurate drawings. In the triple alliance, as it may be called, of description, drawing, and object, is found the easiest, safest, and surest means of successful study. Not only is the Atlas a guide to practical work, but since it contains the results of that work in a permanent form, a glance at the drawings with their accompanying description will serve as a valuable refresher to the memory before going up for examination. Further, the Atlas may be used with any of the Text-books of Zoology or Botany in common use, such as those of Huxley, Nicholson, Macalister, Sachs, M'Nab, etc., because equivalent terms are noted in the text, and thus the language of the science is translated as it were into the different dialects. The drawings belonging to each form represent the leading features in the history of its life. The structure as a whole is first shown, then the details of the various parts by means of separate drawings, and finally so much of the history of its development as is likely to be required. In every case the types represented have been practically examined, and drawings made from nature. A number of the drawings are taken from dissections and microscopic preparations made in the Biological Laboratory of the Royal School of Mines, London. Others are copied from reliable sources whenever they give clearly and correctly the most instructive view of the object. In the development special care has been taken to give only such representations as were drawn by practised observers, e.g. the development of the Amoeba is taken from Haeckel, and that of the Cray- fish from Eathke. Drawings after nature are headed Figures, and Diagrams are occasionally introduced for explanatory purposes. The explanatory text arranges the information obtained from the drawing in a convenient form, explains briefly the nature of the object seen, states equivalent terms when the same thing is differently named by standard authors, gives the derivation of names when that throws light on their meaning, and accents them where there is any danger of wrong pronunciation, and finally sums up the distinctive characters in the form of a classification. 324887 iv PREFACE. A few general practical directions are given to enable the student to adopt those expedients in the examination of specimens which experience has shown to be the best. These instructions are necessarily brief, but a detailed account is less necessary since the methods to be pursued are given clearly and at length in Huxley and Martin's Elementary Biology, to which the student is referred. The following features of the Atlas may be specially mentioned : — The names of the various parts are placed on the drawing. The description faces the Plate. Colour is used to distinguish the different organs, and as a rule, corresponding parts have the same colour throughout in order to render comparison easy. The size of a microscopic object is generally given, or shown by means of squares, to prevent misconception. The comparative Histology of Frog and Man shows that a close correspondence exists between the structure of the Frog and that of higher animals, and thus justifies its detailed study as a representative form. The complete life-history is usually given. Separate drawings are freely used for the different systems of the Plant or Animal body, and thus all the evils and confusion arising from overcrowding are prevented. Equivalent terms allow of its being used with any standard text-book. No apology is needed for issuing a work of this kind. While there are large and well-executed wall-diagrams which the student may admire at a distance, there is no set of drawings at a convenient price and in a handy form which he can use as a map to show him the various regions of the Plant or Animal, and guide him in his attempts to explore them. It is hoped that the cheap and con- venient form of the Atlas may favour its introduction even into higher-class schools. There the study of Biology might be made a powerful instrument, both of information and training, and a valuable preliminary to the study of Physiology. We are much indebted to Mr. S. P. Eastick for valuable aid received while the work was in progress. No pains have been spared to ensure accuracy, yet doubtless some mistakes have escaped notice. EDINBURGH, January 1880. PEEFACE TO THE SECOND EDITION. THE attempt to encournge practical work in Biology by means of clear figures briefly explained, and accompanied by instructions for the examination of specimens, has evidently been received with favour, since a second edition of the " Biological Atlas " has been called for within a year of publication. Both Text and Plates have been carefully revised, and such alterations and improvements made as will tend to render it still more serviceable. However, few changes have been found necessary. The colouring of the Animal portion of the work has been somewhat altered, in order to bring it into harmony with that of the " Zoological Atlas," to which the present work may be regarded as an introduction. D. M'A. EDINBURGH, April 1881. LIST OF PLATES. PLATE / L II. III. IV. PLANTS . . . V. VI. VII. V VIII. IX. X. XI. XII. INVERTEBRATE * XIII. ANIMALS . . XIV. XV. XVI. ^ XVII. f XVIII. ] XIX. VERTEBRATE XX. J ANIMALS . . ' XXI. XXII. XXIII. ^ XXIV. YEAST AND BACTERIA .... BROWN MOULD AND GREEN MOULD .... PROTOCOCCUS AND CHARA ' • • I CHARA (completed) AND BKACKEN FERN BRACKEN FERN (completed) FLOWERING PLANT ..... „ ,, (continued) i! „ HISTOLOGY ...... PROTEUS ANIMALCULE AND BELL ANIMALCULE . FRESH-WATER POLYPE AND EARTH-WORM EARTH-WORM (completed) . .. LOBSTER AND CRAYFISH .... , „ (continued) ...... , „ (continued) . . . . . 4 „ (completed) ...... FRESH- WATER MUSSEL .... SNAIL ...... FROG — EXTERNAL CHARACTERS AND GENERAL ARRANGEMENT OF INTERNAL ORGANS ...... SKELETON • • • • • CIRCULATION AND RESPIRATION . . . . NERVOUS AND MUSCULAR SYSTEMS . SENSE-ORGANS, RENAL AND REPRODUCTIVE ORGANS, AND TADPOLE DEVELOPMENT AND COMPARATIVE HISTOLOGY COMPARATIVE HISTOLOGY OF FROG AND MAN Facing page 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 45 47 49 GENERAL DIRECTIONS FOR PRACTICAL WORK. FOR the examination and dissection of the various specimens the following apparatus will be required : — Dissecting Instruments. — Sharp knife or scalpel; forceps; dissecting needles; scissors; and dissecting dish. Dissecting needles may be readily made by fastening ordinary needles in penholders. To fasten the needle, hold it in a pair of pliers and push the sharp end into the wood ; withdraw the needle again and insert the blunt end. These needles may be made to cut by grinding edges on them. The needle is readily bent by heating in a gas flame and bending with the pliers. Such needles are very useful in dissecting flowers. Dissecting Dish. — A shallow vessel may be used, with a plate of wax, gutta-percha, or black paraffin (prepared by melting down solid paraffin and lampblack) covering the bottom, on which to cut up or pin down the specimen. A tight-fitting lid with a layer of cork fastened to the inside can be used as a dissecting board. Optical Instruments. — Microscope ; pocket lens, which may be used also as a dissecting microscope by having a fixed rod on which it can be moved up or down, leaving the hands free for teasing, etc. ; watch- maker's magnifying-glass, which may be used in dissecting out nerves, blood-vessels, or any minute structures. Small apertures are best made out by taking a glass tube drawn out to a fine point and blowing through it to enlarge the opening. Bristles can then be readily inserted. Reagents, etc.. — Distilled water; weak spirit; solutions of magenta, carmine, iodine, salt, potash, and chromic acid ; glycerine; acetic acid. A weak solution of bichromate of potash may be used instead of spirit for preserving. A good plan for dropping reagents is to fix glass rods in the corks of the bottles. YEAST. Mounting. — Get some Yeast at the brewer's or the baker's, and place a small drop on a glass slide. Cover with a cover-glass for examination under a high power of the microscope. Staining. — Place a little of the staining solution beside the cover-glass, and arrange a slip of blotting- paper at the opposite side, so as to cause a current of the staining material. Crushing. — -By gentle pressure of the finger or some blunt instrument the wall will burst and the contents flow out. To prevent breaking and dimming of the cover-class it is protected by a tiny pad of blotting-paper. BACTERIA. Mince some lean meat and soak in cold water for an hour ; filter, and keep in a warm place for several days ; examiue the liquid and the scum which forms on the surface with the highest power of the microscope. MOULDS. Teasing. — Take a very small portion of the mould and lay it on a slide with a little water, then tease out by means of two dissecting needles. PROTOCOCCUS. Mounting. — Take a bit of the bark of any tree with green scum upon it, brush off the Protococci and mount in water. Mount a drop of water from a water-butt containing Protococci, stain with iodine, which kills the Protococci and renders the cilia visible. CHARA. Hardening. — A weak solution of chromic acid is used. The chromic acid, in addition to its hardening action, acts also as a solvent, dissolving any limy incrustation. Embedding the slender Stem.- — Soak a piece with gum, which will fill up any cavities ; then harden the gum by dipping in alcohol, which removes water, leaving the stem surrounded by a coat of hardened gum. Place a Till little bit thus prepared in a hole scooped out in solid paraffin. Melt a little paraffin in a small spoon and pour around the specimen. Section-cutting. — Wet razor with alcohol by means of a brush. Cut a number of slices and transfer them with the brush to a watch-glass. Add water, the gum dissolves, and the sections become detached from the paraffin. PERN. Sections. — The rhizome cuts better after steeping for some time. Staining. — A transverse section of nbro-vascular bundle, for instance, consisting of hard and close-set cells, may be stained by soaking with magenta for some time in a watch-glass, then washing with water from a pipette before mounting. FLOWERING PLANT. Leaf. — Cut a small piece out of blade of leaf. Dip it into gum and then into alcohol. Imbed in paraffin and cut transverse sections. Peel off a small bit of epidermis from the lower surface, say, of a geranium leaf, and examine in water. Anther. — Take anther from a flower befpre it opens. Dip in gum and alcohol before imbedding and cutting sections. Ovule.— One of the Speedwells may be used, e.g. Buxbaum's Speedwell. Dissect out ovules from ovary of flower from which corolla has just fallen, then tease them asunder under dissecting microscope in a drop of potash solution and add a little glycerine when mounting. Embryo. — The common Shepherd's Purse may be used. Dissect out the mature ovules or seeds from fruit. Commence with youngest fruit nearest the top, afterwards going to older, to get different stages. Mount in potash solution, press gently with cover-glass, and the embryo will be forced out through the micropyle. Seeds. — Beans or Peas are readily examined after steeping for a night in water. Germination. — Wheat and Indian Corn can be readily germinated by placing in moist tow, surrounded by flannel, and kept in a warm place. The root hairs and root cap can be readily seen on these young roots. AMCBBA. Examination. — The readiest place to find some form or other of Amreba is in the slimy matter taken from decaying leaves in stagnant water. Mount in a drop of water and examine like Yeast. COLOURLESS BLOOD-CORPUSCLES. Examination. — Lay a drop of your own blood on a slide, then cover quickly with cover-glass. By means of a camel-hair brush surround with oil to prevent evaporation. VORTICELLA. Examination. — On minute Water-plants, such as Duck-weed, groups are usually found. The operation of feeding may be observed by introducing particles of indigo or carmine into the water. HYDRA. Examination. — Found in stagnant pools and ditches. To examine alive, mount in plenty of water under a large cover-glass. Sections. — Kill by adding boiling water. Harden, prepare, and imbed as in Chara. Sea-anemones treated in the same way might be used instead. EARTH-WORM. Dissection. — Kill with vapour of chloroform by placing in a stoppered bottle, with a few drops of chloro form. It then becomes stretched, and may be dissected under spirit. Fasten out in a dissecting dish, and with a fine pair of scissors slit it up longitudinally a little to one side of the middle line and pin out the two flaps. Needles with borax beads for heads are best for pinning out. IX FRESH-WATER MUSSEL. Dissection. — Cut through adductor muscles of one side and remove the valve. Note the beating of the heart. Kill with hot water. Harden in spirit before following the course of the alimentary canal LOBSTER OR CRAYFISH. Dissection. — Eemove lateral portion of carapace by passing a knife under its free edge from the posterior end to cervical suture. This part of the carapace is the gill-cover or branchio'stegite (Gr. stego, I cover). Notice scaphognathite working. Turn out the gills with the knife. Dissect from the left side, as in PL XIII. figs. 2 and 3. Place another specimen under water in dissecting dish and it soon dies. Eemove dorsal portion of carapace and of abdominal somites with scissors, in order to make out the chief organs, as in PL XIII. fig. 1. Preparation of Skeleton. — Boil in strong potash solution, which dissolves everything but the chitiu or horny substance composing the shelL The parts of the exoskeleton may be disarticulated and laid out in their natural order. SNAIL. The Edible Snail is the largest of all the Snails, hence its convenience for study ; but the Common Snail may be taken. Snails can be kept alive for a considerable time, and warm water generally makes them protrude from their shell. Boiling water kills them. Dissection. — Remove shell bit by bit with strong forceps, and pin the animal out in spirit, dissecting from the dorsal surface. Lay open pulmonary chamber, then expose the viscera by laying open the dorsal integu- ment of foot along middle line and removing the mantle. The viscera may next bo laid out to display them to advantage. FROG. The Edible Frog is chosen on account of its larger size, but the Common Frog will also show the various points. Kill with chloroform. Dissection. — A dissection from the ventral surface may be made under water in the dissecting dish by cutting through the skin in the middle line from the syinphysis of lower jaw to symphysis of pubis ; then pin out the skin on both sides, and various muscles, veins, etc., are brought into view. Next open abdomen a little to one side of anterior abdominal vein, cut through shoulder-girdle, and remove its central portion. The various viscera are then seen as in PL XVIII. fig. 2. Turn over viscera to right side, cut away parts mentioned in PL XVIII. fig. 3 (text), and pin out with left side upwards so as to get the sectional view. Prepare a specimen in spirit and nitric acid for the dissection of the nervous system. Dissect from dorsal surface, and remove the dorsal wall of the cerebro-spinal cavity by nipping it away with scissors, beginning at the junction of the skull and spinal column. Dissect out cranial nerves and the nerves of the limbs for a short distance. Remove brain and spinal cord and preserve in spirit for future use. Take a similarly prepared specimen and dissect from ventral surface. Remove the bodies of the vertebras and the floor of the skull. Along each side of the spinal column dissect out the sympathetic system, and trace its connection with the cranial and spinal nerves as in PL XX. diag. 1. The principal cranial nerves may be dissected from the left side, as in PL XXI. fig. 5, after distending the gullet with a piece of glass tubing. Place in chromic acid, with a little nitric acid to hasten the softening of the bone and the hardening of the nerves. Section of Spinal Cord. — Take a piece hardened in spirit, prepare and imbed in paraffin as before, and mount transverse sections in glycerine. Circulation in Web. — In a thin piece of wood or cork make a notch to fit the web between two of the toes. Stretch the web over the notch by thread attached to the ends of the two toes. Keep the skin moist with wet blotting-paper, and after placing a small drop of water on the web, cover with triangular cover-glass for exam- ination under high power. Preparation of Skeleton. — After cleaning the bones roughly, steep for about a week in sufficient water to cover them, then place them for a few days in fresh water, which should be frequently renewed. They may be cleaned with a brush and then laid out in the sun to bleach. Any grease may be extracted from the bones by benzoL YEAST PLANT (SACCHAROMYCES CEREVISI/E). PLATE I. Fig.2 Yca*t Cell meh Fig. 3. Cell with. Old- Scud & Tm> T Fig. 4- Colony of Cells' Fig. 5. R.7 Crnthftl Potash* WaU/ ui p Fig. 8. / of' Square* * ^0 Air (0. XT/ Diagram I . 6 PHYSIOLOGY OF YEAST Water t O.S.I Sugar- /C. O. f./ ^mrrutnutnt. Tartrate fC.O.'H.NJ fotassium Hun photo fKP. tj ; Calcium fhalphaK, fCa.P.O/ Sulphale f'Mg.S. Carbonic Acid. 1C. O.I noo o oo o oo O 00 O O 00 o o O O O O O OO OOO O O O oo oo o o oo Water Jlcahol I C O. If. I fflyca-int. I c. O S./ Su£ciitif Add. fC. 0.H./ BACTERIA O Fi«. I. O Q 83 Fi.2. Fig. 5. Spu-iUim* Fig. 6. W IcAK John *i on Ea.nlnirjfli i- I'LATE 1. THE YEAST PLANT. Fio. 1. Showing — f Cell-wall or sac. A CELL J Protoplasm (Gr. protos, first; plasma, from plasso, to mould). ( Vacuole filled with cell-sap (L. vacuum, an empty space). FIGS. 2, 3, and 4. Showing — MULTIPLICATION BY BUDDING OB GEMMATION (L. gemma, a bud). The commencement of the process is seen in fig. 2. A bit of protoplasm is pushed out, stretching the cell-wall and making it thin. Fig. 4 shows a cell aggregate or colony produced by a repetition of the process of budding. Fio. 5. Showing — MULTIPLICATION BY ENDOGENOUS DIVISION (Gr. eiulon, within ; gennao, I produce). The protoplasm collects usually into four round masses, each of which takes on a cell-wall. Cells produced in that way are called Ascospores (Gr. askos, a bag; spora, a seed) or Endo- conidia (Gr. endon, within; konis, dust). Fio. 6. Showing — AS'COSPOKES set free by rupture of the cell-wall of parent, and multiplying by gemmation. FIG. 7. Effect of— Magenta — Stains protoplasm, leaving cell-wall comparatively unstained. Crushing — Ruptures the cell-wall, and shows that the cell-wall is tough and resisting, while the protoplasm is semi-fluid. Potasli (KHO) — Dissolves out the protoplasm. Iodine — Stains protoplasm. Fio. 8. Measurement by eyepiece micrometer. DIAGRAM I. PHYSIOLOGY — - a. Shows the composition of a fluid fit to nourish yeast (Pasteur's fluid). Elements which make cell-wall (C.O.H.). Elements which make protoplasm (C.O.H.N.). Elements which make ash (P.S.K.Mg.Ca.). I. Shows the composition of the fluid when acted upon by yeast. Process of fermentation (ferveo, I boil). i Carbonic acid (C02). Sugar becomes J. Alcohol. ' Small quantities of succinic acid and glycerine. About two per cent, of sugar is unaccounted for. Ammonium tartrate, etc., used up by the yeast. Total result / Manufacture of alcohol and carbonic acid. ( Manufacture of cell-wall and protoplasm. CLASSIFICATION OF YEAST. Kingdom — Plant®, because it possesses a cell-wall made of cellulose, and can manufacture protoplasm. Sub-Kingdom — Thallophyta, because it possesses neither root, stem, nor leaf. CJfisa — Protophyta, because it has no sexual process of multiplication (Gr. proton, first; pJiyton, plant). A COMMON BROWN MOULD (MUCOR MUCEDO). PLATE IL Fig. I Macar 4- &crmir toting Ctrrnxnaiing Carpogortium Fi g. 4- . Development of Carpoganixarv frit Cortical cfUs of - the Leaf FJ*. I. Parts of a Fern, a THE BRACKEN FERN (PTERIS AQUILINAj Fig. 3. Partj in* t Portion of Rht g lateral Pinnule farm btlt>\v &? A A. B. \ TWketL Venation 7. f)f*tl*ivmeru tf~ Spore W ItA K Joim»ton.J>auiWfh & London PLATE IV. O-tl.jCX-tvr.QL continued. FIG. 1. PORTION OF LEAF. Showing — Autheridium, male organ, or globule. Carpogonium, female organ, nucule, sporangium, or spore-fruit (Gr. spora, a seed ; cmgeion, a vessel). FIG. 2. THE ANTHEEIDIUM DISSECTED. Showing — a. Shield. Manu'brium (L. a handle). Capitulum (L. a little head) (blue). Secondary capitula (blue). Not named on drawing. Filaments. I. Portion of filament, with a spermatozoid in each of its cells. c. A liberated spermatozoid, with two long cilia. FIG. 3. THE CAEPOGONIUM OB NUCULE — Central cell. Twisted filaments, quite different from the filaments of the antheridium. The one-celled corona in Chara, and the two-celled corona in Nitella. FIG. 4. DEVELOPMENT OF THE CAEPOGONIUM OR SPOEE-FRUIT. Sectional view. FIG. 5 and DIAGRAM I. Showing DEVELOPMENT OF THE SPORE, enclosed in sporocarp — Proembryo. Pseudo-whorl of leaves, with the Chara in its axil. CLASSIFICATION OF CHARACE^. Kingdom — Plantsc. Sub-Kingdom — Thallophjta (exceptional in having axis and appendages). Class — Carposporeoe, because it has a spore fruit. Group— Algos. Order — Characese. Genera — Chara and Nitella. THE BRACKEN FERN. FIG. 1. Showing— ( lludimentary leaf. LEAVES -f leaf. I Cut leaf. Old leaf. Underground stern or rhizome (Gr. rJu'za, a root ; omos, the same as) with its growing point. lioots. 8 Fia. 2. LATERAL LINES OF RHIZOME. FIG. 3. Showing — i Rachis (Gr. rachis, a spine, ridge). a. PART OF LEAF OR FROND . . . . < Pinna (L. a feather). I Pinnule (L. pinnula, a little feather). . m TI f Indusiuni (L. induere, to clothe) covering spore-cases. I. Two PINNULES VIEWED FROM BELOW { * ( Sorus (Gr. soros, a heap), a cluster oi spore-cases. FIG. 4. Showing FORKED VENATION AND INDUSIUM. FIG. 5. SPORE-CASE OR SPORANGIUM. Showing — Stalk. Case. Anmilus (L. a ring). In c, a small part below the spores is inadvertently uncoloured. Spores. FIG. C. SPORE. Showing — Exosporium (Gr. exo, outside ; spora, a seed). Endosporium (Gr. endun, within ; spora, a seed). Protoplasm with oil-globules. Nucleus. FIG. 7. DEVELOPMENT OF SPORE. Showing— a. Endosporium protruded. 6. Divided to form a young prothallus, with root-hairs. c. Old prothallus with root-hairs, male organs or antheridia, and female organs or archegonia (Gr. archos, chief; gone, seed). FIG. 8. PROTHALLUS UNDER HIGH POWER. Showing — C Cell-wall. CELLS . . J Prot°Plasm- ' | Chlorophyll granules. L. Largo vacuolcs filled with cell-sap. ^ (CoN-rr>-) PLATE V. Fig. 2. j&rckeffOratulL of Royal fern idj of' Utiyai Fern Elevation. F1J.4-. Cmlnil <•<•// furthr Archttfonium alter ferlUiratwrt / .Central all itiifidtd Jrc/toti. of' -»«/< TioJci-ei c Fid. 7. Trust* &• Ijttrul" ,tffti€Hi ttfw fitirtimi •>!' thri RJli\innr under Itm pawrr. Rhizome - Trari*. Long*: Section* Fi^.9. ObtiiflH- Action ul'tftilk iit'Lraj' a Tranrrrraf't^ Forlian of' Pitrv Vascular Hltlldle llndtrhiyh ptnfei \ // IV? 0 v • si " ' / / ' • ' ' ' ' ' ' ' ' ' y- ^jf. StaOarifai-m. ivtfOf n -. / lIlilllilM' Wood, or K John- ton. Edinburgh 4 Londo: PLATE V. FB.LV.N continued. FIG. 1. THE ANTHERIDIUM AND ANTHEROZOIDS OF THE ROYAL FERN (Osmunda Regalis), under surface ol prothallus (green). FIG, 2. THE ARCHEGONIUM WITH ITS CENTRAL CELL OR GERM-CELL. FIG. 3. DIVISION OF CENTRAL CELL INTO FOUR IN THE BRACKEN. FIG. 4. CONNECTION OF YOUNG BRACKEN FERN WITH ITS PROTHALLUS BY MEANS OF THE FOOT. FIGS. 5, 6. TRANSVERSE AND LONGITUDINAL SECTIONS OF THE KHIZOME. Showing — Sc.i. Outer scleren'chyma (Gr. skleros, hard; enchuma, tissue). G. T. Ground tissue or paren'chyma (Gr. para, together ; enchuma, tissue). F.-V. B. Fibre- vascular bundles — outer. Sc.2. Inner sclerenchy ma. G. T. Ground tissue. F.- V. B. Fibro-vascular bundles — inner. FIG. 7. TRANSVERSE AND LONGITUDINAL SECTIONS OF RHIZOME. Showing — Epidermis, sub-epidermis, and parenchyma loaded with starch granules. Fibro-vascular bundle with scalariform and spiral vessels. Parenchyma with starch. Sclerenchyma very thick walled (Gr. skleros, hard). FIG. 8. PORTION OF FIBRO-VASCULAR BUNDLE. Showing — Cells of fibro-vascular bundle sheath. Cells of bast sheath with starch granules. f Bast fibres or hard bast. BAST OR PHLCEM < Bast vessels. "j ( Bast parenchyma or proeambium. j ( Scalariform vessels. WOOD OR XYLEM -I Spiral vessels. ( Wood parenchyma. Note. — In the complete bundle the bast forms a ring surrounding the wood. FIG. 9. PART OF AN OBLIQUE SECTION OF A LEAF-STALK. Showing the scalariform vessels (L. scala, a ladder* of the bundle. CLASSIFICATION OF FERN. Kingdom — Plantae. Sub-Kingdom — Vascular Cryptogams (Gr. kruptos, hidden ; gamos, a marriage). Vascular, because they possess fibro-vascular bundles ; cryptogams, because the sexual organs are hidden on an inconspicuous prothallus. Class — Filicinas. Order — Filices. Genus — Pteris (Gr. pteron, a wing). Species — Aquilina (L. aquila, an eagle). Common Name — Bracken Fern. B THE FLOWERING PLANT PLATE VI. Diagram I TkfLtat'y Fig 2 3efti0n of Onion KuitL* vf Leaxt* Grmpotirtd pinnate Tea/ with Tmdrila, & 2 free. Lateral stipule* ton. Edinburgh I London- 11 I PLATE VI. THE FLOWERING- PLANT, DIAGEAMI. Showing— o,, ( Nodes, bearing leaves (L. nodus, a knot). I Internodes, bearing no leaves (L. inter, between ; nodus, a knot). ( Leaf. APPENDAGES OF STEM < Bud, a shortened stem with crowded leaves. ( Branch, an expanded bud. p „ f Axillary, in the angle between the leaf and stem (L. axilla, the armpit). 1. OSITION OF ijTJDS . } ... . , I Terminal. FIG. 1 (a). THE HOESE CHESTNUT. Showing — Intemodes. Nodes with leaf-scars. Two axillary buds. Terminal bud. FIG. 1 (b). THE SAME. Showing the scars left by the falling off of the bud-scales. These scars mark the commencement of a year's growth. FIG. 2. BULB OF ONION. Showing — Stem, short. Leaves, crowded, and stored with nutriment. Buds (1) terminal and (2) axillary. Roots, fibrous. The peculiarity of the Onion is this : it remains permanently in the bud condition. A permanent bud of that kind is called a bulb. FIG. 3. Showing KINDS OF LEAVES — Scale leaves. Foliage leaves — the green leaves which manufacture starch (L. folium, the leaf). Bracts — leaves near flowers (L. bractea, a thin plate). Floral leaves (L. flos, a flower). (Red.) FIGS. 4, 5. EXAMPLES OF LEAVES — Pinnate leaf, with elongated midrib (Pea). Palmate leaf, with extremely short midrib (Horse Chestnut). Compound leaf. The incisions extending into the midrib, and subdividing one leaf into a number of leaflets. Stipules — appendages originating from the base of leaf-stalk, not from the stem. FIG. 6. Showing FOLIAGE LEAVES united or connate (L. con, together ; natus, born). FIG. 7. FLOWEE OF PEA. Showing — Sepal leaves united below (gamosepalous calyx). Petal leaves of unequal size (irregular corolla indicated in formula by V). FIG. 8. Showing GENEEAL STEUCTUBE OF THE FLOWEE — Calyx (Gr. kalyx, a cup). Corolla (L. corolla, a little crown). Stamens or Androecium \ _,.. ,.~, i -7 ( Filament (L. filum, a thread). (Gr. aner, malejoi&w, > : '. , \ / i \ I Anther containing pollen-erams. house) (male organs) ) Pistil or Gynoecium (Gr. j Ovary containing ovules. gune, female ; oikos, > Style. house (female organs) i Stigma (Gr. stigma, a brand). FIG. 9. PLAN OF PEA FLOWEE. Showing — Calyx = five sepal leaves united. Corolla = five petal leaves separate. Androecium = ten stamen leaves, nine united and one free. Gyncecium=one carpel leaf. Formula V Ca. (5), Co. 5, An. (9) + 1 Gn. 1. THE FLOWERING PLANT PLATE VI I. Diag. I . Section- of Flow tr Fid. 3. Traiuvfrte tfectwn-- tff' Anihfr of' Tulip 2 ~Niux. Yomit-a teed, with ons. kail* remove 2 6'ectif^i' of Almond 3 3*ta,- LcaxL open & Teata remar^d 4- Thf Sean, S JTuJJe-in H-ufi TtJtti & ant. cotyledon. Ter c Cptyltdan p Flumulf r Radicle Fid. 4-. o Young Bfan Plant Oiag 4. ?t7rnta£ton -each mother- cilL forms + ffoUfrt- graxne W t A.K Johttiwn, Jidinbutgk 1 Lon 13 t PLATE VIL THE FLOWERING PLANT. DIAGRAM I. Showing— RECEPTACLE OR THALAMUS TO WHICH THE FLORAL LEAVES ARE ATTACHED. /'Calyx, hypogynous or inferior (Gr. Jiupo, under; gune, the female INSERTIONS OF FLORAL \ Corolla, hypogynous or inferior. .LEAVES I „. , I Stamens, hypogynous. ^ Ovary, superior or free, containing an erect ovule. DIAGRAM II. Showing— f Stigma, for receiving pollen. PISTIL OR GYNOICIUM . . •< Style. (. Ovary, containing one ovule. IMPREGNATION OF OVULE Pollen-grains attached to stigma and throwing out pollen-tubes, which make their way down the style, enter the micropyle of the ovule, and fertilize the germ-cell in the embryo-sac. DIAGRAM III. Showing— f Primine or outer coat (L. primus, first), formed after inner coat. OVULE •< Secundine or inner coat (L. secundus, second). ( Nucleus, with a giant cell — the embryo-sac. C Wall of sac. EMBRYO-SAC FERTILIZED -< Embryo. (. Endosperm. FIG. 1. Showing the RIPE PISTIL OF PEA — PERICARP — Ripe wall of ovary, dry and splitting into two valves. SEED — Ripe ovule. FIG. 2. Showing SEEDS — f Testa or seed-skins (L. testa, a shell). A -< Endosperm, the so-called albumen (Gr. endon, within; sperma, a seed; (Albuminous Seed) (^ Embry0) with two cotyle'donS) or seed-leaves. 0 ALMOND f Testa. ,. -< Endosperm absorbed into embryo. (Exalbummous Seed) J -n , .., , . , ,, ' v Embryo, with two eotyle dons. 3. PEA (Exalbummous Seed). j K T, ( Testa, 4 and 5. BEAN I .„ , . /T, ,, c, ,, •{ Endosperm absorbed. (Exalbummous Seed) j ,-, , ... ... ' I, Embryo, witli two cotyledons. C Cotyledons. EMBRYO J Plumule. ( Radick. FIG. 3. ANTHER OF TULIP, showing libro-vascular bundle in centre corresponding to the midrib of the leaf. Right anther-lobe with two pollen-sacs. Left anther-lobe with two pollen-sacs. DIAGRAM IV. FORMATION OF POLLEN-GRAINS BY ENDOGENOUS DIVISION. FIG. 4. YOUNG BEAN PLANT, showing — Axis j '£ap-r°ot ( Stem with terminal bud. I Rootlets. APPENDAGES J 2 Cotyledons. V. Foliage leaves. HISTOLOGY OF FLOWERING PLANT PLATE VI I L Oiig. I ection- of young stem/ of Rons & chestnut. talk afHursr. cA&rt nut Fid.5 Long*. Seeiijun at' Rttot diameter) FicS.2. Amoeba cut s&en, a^JjitervaLs of a few second* Fig. 3. Z tfe- history of Atruoebcu I, fi-uds fro O>. entyvteeL -form. Fig. +. Colourless Corpuscles of Bwnani~bloo. Section- ofjrastndas .Endoderm' -with, EARTH-WORM (LUMBRICUS TERRESTRIS) Fig 2._Thefi'f\een Anterior Segments -Ventral aspect •• - Fig I. _ Sarthwornv "W iA.K.JolinsToji. Edinburgh t Londoi 19 PLATE X. FRESH- WATER POLYPE. GENERAL CHARACTERS — FIGS. 1, 2. Foot or liydrorhiza (Gr. rJiiza, root) attached to some floating body. Mouth at free end. Tentacles or feelers (L. tentare, to feel) surrounding the mouth. ( Testis, the male organ. Reproductive organs j Oyary> the female orgM_ Multiplication by budding or gemmation (fig. 2). GENERAL STRUCTURE — DIAG. 1. Ectoderm (Gr. ektos, outside; derma, skin) (red). Endoderm (Gr. endon, within). Body-cavity, serving also as a digestive cavity, and continued into the tentacles. MINUTE STRUCTURE OR HISTOLOGY — FIG. 3. Ectoderm-cells with contractile prolongations — neuro-muscular cell-layer. Nuclei and nematocysts in the cells. FIG. 4. Endoderm-cell with cilium on its inner surface. FIGS. 5, 6. Thread-cells or nematocysts (Gr. nema, thread ; htsfos, a bag), consisting of capsule, filament, and three recurved spines at base of thread. REPRODUCTION OR SEXUAL PROCESS — FIG. 7, «. Spermatozoon (Gr. sperma, seed ; zoon, an animal) with oval head and vibralile cilinm. b. Ripe ovum, consisting of vitellus or yolk, germinal vesicle or nucleus, and germinal spot or nucleolus. e. Impregnated ovum divided into a number of cells, surrounded by a capsule — burst to-show the contents. MULTIPLICATION OR ASEXUAL PROCESS — Process of gemmation shown in fig. 2. DEVELOPMENT OF HYDROZOA — DIAG. 2. The impregnated ovum by division becomes a mulberry-like mass or morula, the morula becomes hollow by the accumulation of fluid in its interior, forming a planula, and the planula by gradual thinning opens at one end, becoming the so-called gastrula, which passes into the mature form. ffoie. — In the Hydra itself there is no proper planula stage, as the two-layered form represented in c has no cilia. CLASSIFICATION — Sub-Kingdom — Cffilenterata (Gr. koilos, hollow ; enteron, an intestine), because it is composed of two cell-layers — ectoderm and endoderm — and has no cavity separate from the body- cavity. Natural Order — Hydrozoa, because a digestive sac is not marked off from the body-cavity, and the reproductive organs are external. Genus — Hydra. Common Name — Fresh-water Polype (Gr. polus, many ; pous, a foot). THE EARTH-WORM. EXTERNAL CHARACTERS — FIG. 1. The segmented body with a mouth at one end, an anus at the other, and a swollen portion called the ciugulum (L. a girdle) or clitellum (L. clitellee, a saddle). FIG. 2. Mouth situated on the 2nd segment. External and internal pair of setae (L. seta, bristle). Openings of segmental organs, one on each side of all the segments except the two first. Openings of spermathe'cte or receptacles of the spermatozoa (Gr. ttperma, seed; thr.ke, a repository). Openings of vasa defcrentia (L. excretory ducts) on ventral face of loth segment. Openings of oviduct on ventral face of 14th segment. EARTH WORM. (LUMBRICUS TERRESTRIS)-(CoNTD-) PLATE XI. Fig. I Laici open, fhorrv I)v inch Ventral yangUonit, chum natraZ. t A.K Jobumott. Edinburgh Jc Londun 21 PLATE XI. THE EARTH-WORM— continued. DISPOSITION OP INTERNAL ORGANS — FIG. 1 and DIAGRAM — ALIMENTARY SYSTEM. BLOOD SYSTEM — CIRCULATORY AND EESPIRATORY . . / Mouth. Cut end of muscular pharynx. Gullet, Crop, a dilated portion of gullet. Gizzard, whitish, thick, and muscular. Intestine leading straight to anus, and covered with a brownish mass supposed to be the liver. Colourless corpuscles in perivisceral cavity — two shown. Pseud-haemal vessels contractile, and therefore circulatory — Supra-intestinal vessel (L. supra, above). Sub-intestinal vessel (L. sub, under). Sub-neural vessel. Commissural vessels connecting supra-intestinal and sub- intestinal vessels. REPRODUCTIVE SYSTEM . . J Dilated commissural vessels in the region of the reproduc- tive organs, the so-called hearts. ' Coloured fluid without corpuscles contained in pseud-haemal vessels acts as an oxygen-carrier, and is therefore respira- tory in function. RENAL SYSTEM Segmental organs in pairs in each segment. /Cerebral or prae-oral ganglia connected by commissural cords embracing the pharynx with the NERVOUS SYSTEM . . . . J Sub-cesophageal or post-oral ganglia which form the anterior extremity of a V Chain of ganglia extending to end of body. Ovaries and oviducts. Testes and vasa deferentia shown in fig. 2. FIGS. 2, 3, 4. RENAL AND REPRODUCTIVE SYSTEMS — Segmental organs with internal ciliated opening and external pore (tig. 3). ( Anterior pair of spermathecae. ( Posterior pair of spermathecas. ( Anterior pair of bilobed testes. ( Posterior pair of testes. l Anterior reservoir of testes with duct. \ Posterior reservoir of testes with duct. Common vasa deferentia. Capsulo-genous glands for secreting egg-capsules. Ovaries. Oviducts with wide ciliated internal opening and external opening (fig. 4). FIG. 5. Ovary with ova. When laid the eggs are enclosed in clusters within a chitinous case, each egg consisting of — Vitelline membrane. Vitellus. Germinal vesicle. Germinal spot. Spermatozoa from Spermatheca. CLASSIFICATION — Sub-Kingdom — Annelida (L. annulus, a ring), because the body is segmented ; without jointed limbs ; nervous system forms a ring round gullet, followed by a ventral chain of ganglia. Natural Order — Oligochse'ta (Gr. oligos, few ; chaite, hair), because the bristles are in rows, not tufted. Genus — Lumbricus. Common Name — Earth-worm. LOBSTER (HOMARUS VULGARIS) PLATE XI I- Fi g. I Side view CephaZo omite, -n-M Kltan. dmiat . (rayflsfi Pf vtopoctite I i ['..x-ffjiut.li Eiulopodiutt, I I £pipodit& W it A K. Johnswn. Edia>iiirgh 3c Undo 23 PLATE XII. LOBSTER AND CRAYFISH. EXTERNAL CHAEACTEES — FIG. 1. ENTIEE SPECIMEN — ,-,,,,,, /r, , . , , , ,, , , ( Cervi'cal suture between head and thorax. Co phalo-thorax (Gr. kephale. head ; thorax, a breast- I i , \ \ , A < Frontal spine or rostrum (L. the beak), a plate) covered by Carapace . J " V prolongation in iront. Abdo'men — six segments and a backward prolongation, the telson (Gr. a limit). C Cephalic. APPENDAGES -J Thoracic, including great claws or chelse and ambulatory limbs. V. Abdominal, including the swimmerets. FIG. 2. THIED ABDOMINAL SOMITE — ( Tergum (L. the back) or dorsal portion. BODY-SEGMENT -j Pleuron (Gr. a side). t Sternum (Gr. sternon, the breast) or ventral portion. f Proto'podite or basal portion (red). APPENDAGES J. Exo'podite or outer terminal portion (blue). (, Endo'podite or inner terminal portion (yellow). Fio. 3. SIXTH ABDOMINAL SO'MITE AND TELSON : a, Lobster ; b, Crayfish — Exopodite divided transversely into two pieces. Telson divided transversely in Crayfish, undivided in Lobster. FIGS. 4, 5. APPENDAGES OF FIEST AND SECOND ABDOMINAL SOMITES IN THE MALE — FIG. 4. Endopodite, bearing a small inner process. FIG. 5. Exopodite gone. Endopodites grooved inwardly, so that the two scooped portions brought together form a kind of channel. FIG. 6. APPENDAGES IN OEDEE — 1. Ophthalmites or eye-stalks (Gr. ophthalmos, the eye). 2. Anten'nules with opening of auditory sac. 3. Anten'nse or feelers with opening of green gland. HEAD — six pair 4. Mandibles (L. mando, I chew). 5. Maxillae, first pair. 6. Maxillae, second pair with boat-shaped scaphognathite (Gr. slcaphe, a boat j gnathos, a jaw) for baling out and drawing in water (blue and green). Maxillipedes or foot-jaws — 7. First pair, epipodite (green) without a gill. 8. Second pair, epipodite gill-bearing. -eight 9 Third pai]-j epipodite Chelse or pincers (Gr. chele, a claw), epipodite gill-bearing (fig. 1). 10. Ambulatory limb (L. ambulare, to walk), epipodite gill-bearing. The four pair are seen in fig. 1. ABDOMEN — six pair (see figs. 1-5). NOTE. — Seven joints of chelse and ambulatory limbs are named in order as follows (see No. 10) — 1. Coxo'podite (L. coxa, the hip) or proximal joint. 2. Basi'podite . . . . \ . o T I,-' Ti /n • !• it. i • \ c fused together in chela. 3. Ischio podite (Gr. ischwn, the hip) ) 4. Mero'podite (Gr. meros, the thigh). 5. Carpo'podite (Gr. Jcarpos, wrist). 6. Pro'podite (Gr. pro, in front of). 7. Dactylo'podite (Gr. ddktulos, a finger) or terminal joint. Six joints of antenna in order (see No. 3) — Coxo'cerite (Gr. keras, a horn). Basi'cerite articulated with an outer llat plate, scaphocerite. Ischio'cerite. Mero'cerite. Carpo'cerite. Pro'cerite, the long many-jointed feeler. LOBSTER (HOMARUS VULGARIS)— CONT"- PLATE XIII. Longitudinal Horizontal Section iFemale/ y Fig. 2. Longitudinal Vertical Sectipn i Ma Fig.3. FRESH-WATER CRAYFISH ( A S T A C U S FLUVIATIUIS , (Female | K Jobsaton Edinburgt feLoi 25 PLATE XIII. LOBSTER AND CRAYFISH— continued. GENERAL ARRANGEMENT OF INTERNAL ORGANS — FIGS. 1, 2, 3. BODY IN SECTIONAL PLAN AND ELEVATION — Mouth. Gullet. ALIMENTARY SYSTEM Stomach, with its cardiac or anterior end (Gr. Mrdia, the heart), and its pyloric or posterior end (Gr. puloros, a gatekeeper) leading into Intestine ending in Anus. Liver made up of two symmetrical halves. CIRCULATORY SYSTEM j , ( Arteries — Sternal, superior abdominal, and inferior abdominal. RESPIRATORY SYSTEM — Branchiae (Gr. gills), twenty on each side in Lobster, eighteen in Crayfish. HENAL SYSTEM — Green glands situated at the base of antennae. ( Supra-cesophageal ganglia. NERVOUS SYSTEM . \ Circum-cesophageal commissures. i buD-ffisopnageal ganglia. V Chain of eleven ganglia. ' Testes with their vasa deferentia opening on the base of last thoracic REPRODUCTIVE SYSTEM I appendages (fig. 2). Ovaries with their oviducts opening on the base of last thoracic appen- dages but two (fig. 3). LOBSTER (HOMARUS VULGARIS)— CONTD- PLATE XIV. Fi*. 1 £l.ei'a/tiiti- & Plate <>t' Xtoinach Diag.2 FJevution &, Plan of Mfart Fig. 4-. Gauftric sictLclan.~nvdf, uics osgtfd^ 7\-terifs osridt ur Anterior pi&e& 'OrocarduiC' or Po Diag. I. Circulatory- & Jtefpiralor\- Systems ~FtJbroiL& Diag .3. OvtiJYi-after'pci.ssiJUj 8 loea* of luAittr -juft left the e>"> i».8 .Mature Craj-~l'i. Cornea/ to Optic' ganglion/ flimmtt of the* Mctinn of Vertebrate, EY& ranular layo tt&ncn, CorntcuA-, Cone Fig. 12 Striped All c curpuscfarofthe blood trvt-cett fram.(/aiujlion. primary him- attatfad- to watt, of StLC' '•Secondary fiairs r ItAK Jolm.lan.Eamt-or^h ILtndon 29 PLATE XV. I_i O -D S T B R continued. NERVOUS SYSTEM- FIG. 1. VENTRAL CHAIN of 13 GANGLIA united by commissures — Cerebral or supra-ossophageal ganglia anterior to gullet, giving off optic nerves. Circum-cesophageal commissures round gullet. Sub-cesophageal ganglia posterior to gullet. 5 Remaining thoracic ganglia, united to one another by double nerve-cords. 6 Abdominal ganglia, united to one another by single nerve-cords. Note. — The numbers attached to ganglia denote the cephalic, thoracic, or abdominal segments to which they belong. FIG. 2. VISCERAL NERVES in Elevation and Plan- Nerves arising from — Cerebral ganglia — -A'zygos — median, and branching posteriorly to form lateral azygos. f Mandibular. COHMBMUBAI GANGLIA 3 Anterc-kteral. 1 Medio-lateral. V, Postero-lateral. Hepatic formed by the union of postero-latural and lateral azygos. SENSOKY ORGANS — FIGS. 3, 4. GENERAL STRUCTURE OF EYE — Cor'nea, the transparent cuticle divided into a number of four-sided areas or facets (fig. 4). Radiating fibres (two are coloured red). Optic nerve expanding into optic ganglion. Flexible stalk. FIG. 5. MINUTE STRUCTURE of one of the elements of the COMPOUND EYE — Cornea. / Cone. NERVOUS ELEMENTS J ° ' ^ Spindle. ' Nerve-fibril continuous with ganglion. ( Investing nervous elements and ganglion. SHEATH J Outer end continuous with cornea. I Inner end continuous with adjacent sheaths. V Oval nuclei and pigment layers. I)IAG. 2. FORMATION OF THE VERTEBRATE EYE — a. Optic vesicle, a hollow process of the- brain, involution of integument meeting it and pushing it in. b. Crystalline lens, a detached portion of thickened integument. c. Pietina, the wall of the doubled-up optic vesicle nearest the lens (red). Choroid, the wall nearest the brain (blue). Rod and cone layer of retina embedded in the choroid by obliteration of the cavity between. DIAG. 1. NERVOUS ELEMENTS OF RETINA compared with nervous elements of fig. 5 — Rod, cone, and outer granular layers = cone, rod, and spindle. Nerve-fibrils continuous with optic ganglion in both. FIG. 6. Base of antennule cut open to show auditory sac. FIG. 7. SECTION THROUGH AUDITORY SAC — Auditory opening. Sac, an involution of the integument lined by hairlikc filaments and containing fluid and grains of sand. Auditory nerve from cerebral ganglia. FIG. 8. Hairlike filaments magnified. EXOSKELETON FIG. 9. Vertical section of shell or exoskeleton. The epidermis thrusts off successive layers of its substance, which form a number of delicate laminae superimposed upon one another, and this is impregnated with salts of lime. The exoskeleton thus formed is cuticular, to be distinguished from cornified epidermis, as nails, composed of modified cells, a cellular exoskeleton. CLASSIFICATION — Sub-Kingdom — Arthro'poda (Gr. arthron, a joint; pous, a foot). The body is segmented; limbs jointed ; nervous system forms a ring round gullet, followed by a ventral chain of ganglia. Natural Order — Crustacea (L. erusta, a crust), because it breathes by gills ; has two pair of antennse (lesser and greater) ; walking legs borne by thorax and abdomen. Genera — Homarus, Astacus. Common Names — Lobster, Crayfish. FRESH WATER MUSSEL (ANODONTA CYNEA). PLATE Fi £. 1 . a Sid& view - Iffy mantle 10b& b Dorsal **r- fjj.5 Organ ofjanaf &• Heart, - side, via, 31 PLATE XVI. THE FRESH- WATER MUSSEL. GENERAL STRUCTURE OF BODY — FIG. 1, «. SIDE VIEW OF ANIMAL when left valve and left mantle-lobe are removed — Mouth, anterior. Anus, posterior. Heart, dorsal. Foot, ventral. Gills, lateral, inner and outer. Labial palps, two on each side of month. Adductor muscles, anterior and posterior, for closing the shell Right lobe of mantle, lateral. FIG. 1, b. DORSAL VIEW OF ANIMAL, partly dissected — Heart. Pericardium. Vena cava in floor of pericardium. Organ of Bojanus beneath pericardium. Intestine entering pericardium. DIAG. 1. TRANSVERSE SECTION OF ANIMAL — • Mantle-lobes, right and left, lateral extensions of the dorsal integument. Outer gill made up of two lamellae. Inner gill made up of two lamellae. Foot, median. Pericardium. f Ventricle. Heart •> T, . , ( Iwo auricles. Intestine piercing ventricle. Vena cava. Organ of Bojanus, beneath pericardium. ALIMENTARY AND NERVOUS SYSTEMS — FIG. 2, a. ALIMENTARY SYSTEM — Mantle and gills removed on left side, and coiled intestine dissected out in foot. Mouth, below anterior adductor. Gullet. Stomach. Intestine, with neural flexure. Anus, above posterior adductor. FIG. 2, a and b. NERVOUS SYSTEM DISSECTED OUT — Cerebral or cephalic ganglia, two at base of labial palps. Pedal ganglia, two united and embedded in foot. , Pari'eto-splancliuic ganglia (L. parietes, walls ; Gr. ftplanclma, the entrails), beneath posterior adductor. Commissures uniting pedal and parieto-splanehnic with cerebral ganglia. SENSE ORGANS — • FIG. 3. Cyclas cornea, a fresh-water form belonging to the same natural order as Anodon, in the foot of which the auditory organ can be conveniently examined under the microscope. FIG. 4. AUDITORY ORGAN OF CYCLAS — Auditory sac lined with ciliated cells and containing fluid and an otolith in the centre. Auditory nerve from pedal ganglion (not shown). CIRCULATORY AND RENAL SYSTEMS — FIG. 5. THE ORGAN OF BOJANUS dissected from left side, left auricle turned up — J Auricles receiving blood from gills. Ventricle with anterior aorta aud posterior aorta distributing blood to the body. 32 Vena cava receiving the blood of the body which passes through the organ of Bojanus to the gills. ( Transparent non glandular portion or vestibule communicating with ORGAN OF exterior and with the BOJANUS ) Brownish glandular portion communicating with pericardium by two (. oval openings (see fig. 1, b). RESPIRATORY SYSTEM — FIG. G, a. GENERAL STRUCTURE OP GILL, section through line ab in diagram 1 — Inner and outer lamellae. Partitions between lamellae — interlamellar partitions. Pairs of chitinous rods in the parallel and vertical gill-filaments, indicated by pairs of dots. FIG. 6, l>. MINUTE STRUCTURE OF GILL, section of lamella parallel to surface in region of chitinous rods — Gill-filament strengthened by pair of chitinous rods. Openings between filaments furnished with ciliated epithelium. Partitions between filaments, interfilamentar, consisting of horizontal and obliquely crossed fibres. MUSCULAR SYSTEM — FIG. 7. MUSCLES — Anterior and posterior adductors, adducting or bringing together the valves. Protractor of foot. Anterior retractor of foot. Posterior retractor of foot. Smaller retractors arising near umbo, impressions only shown (fig. 8, a). EXOSKELETON — FIG. 8, b. EXTERIOR or SHELL — Rounded anterior end, tapering posterior end. Umbo or beak on dorsal surface of each valve towards anterior end. Concentric lines of growth. Elastic ligament behind umbones, binding the two valves together, and tending to open the valves. The hinge-line is without interlocking processes or teeth, hence the name Auodon (Gr. a, without ; odous, odontos, a tooth). FIG. 8, a. INTERIOR OF SHELL — Pallial impression indicating attachment of muscular ventral edge of mantle to shell. Anterior and posterior adductor impressions. Successive adductor impressions, extending from cavity of umbo to each adductor muscle, and indicating the travelling downwards of adductor muscles. HISTOLOGY — FIG. 9, a. Liver invests stomach, and consists of blind tubes lined with epithelial cells. b. Muscle composed of elongated nucleated cells resembling those of smooth muscle in form (PI. XXIV. fig. 7), but having the structure of striped muscle. c. Blood-corpuscles, colourless, nucleated, and amo3boid. DEVELOPMENT — FIG. 10, a. Eipe ovum with its vitelline membrane forming a short tube at one point with an opening or micropyle. I, c. Embryo when hatched or Glochidium — b enclosed in vitelline membrane, c escaped from it. f Valves of shell triangular (see fig. 6), united at base and incurved at DIFFERENCES \ apex. FROM ADULT 1 Singie adductor muscle. v Byssus or beard coming off from foot. CLASSIFICATION — Sub-Kingdom — Mollusca (L. mollis, soft). The body is soft and unsegmented ; possesses a shell, and three pair of nervous ganglia. Natural Order — Lafnellibranchiata (L. lamella, a plate ; Gr. branchia, a gill), because it has a bivalve shell ; a two-lobed mantle ; plate-like gills ; and no distinct head. Genus — Anodon'ta (Gr. a, without ; odous, odontos, a tooth). Common Name — Fresh-water Mussel. EDIBLE SNAIL (HELEX POMATIA). PLATE XVII. Ffcr.5. BuccaL mtus /a// suit, view i^. I . Setix ptmiatia Ffo.3. Xmiqiiudinal Vertical Jeetwn. .' of Rectum F 1 6 . 6 . 0' . Horny upper jaw Qiatf. !.£*>/«/* Kv*. Srction portion of (ttionlopho b Laru/^ Vertical- rft-cfion. -Poster ior&id of Radula+ . ^^ ^ Oiatf.2. Circulatory Centres >- L Fig". 4 DorfoL vtew vvitJi' the surface ofmanik -Portion; of foot -Anterior lordsr ofAfantlc -CffUor Conjunctiva/ -•''" Corneas'' ' thf> Uning of Fatiial chamber- Fig. 7. Generative. % ot&tr organs nf FiJ.IJ HUnd^ut ofPaVidt a/'(h-otcftis i'imt. forming \ Fully form f ft Jptrrnatmoi cancLb probably communicating -with, exterior W. VA.K Jolin PLATE XVII. THE EDIBLE SNAIL. EXTERNAL CHARACTERS — FIG. 1. THE SNAIL protruded from its shell — TT , f Pair of tentacles or eye-stalks with eyes. HEAD bearing < J ( Pair of tentacles without eyes. Foot flattened out ventrally, hence the name Gasteropod (Gr. yaster, the belly ; pous, a foot). Shell univalve and spiral. FIG. 2. SHELL — Body-whorl, the last and largest whorl with the mouth. Spire, the rest of the whorls. Five brown bands running in the direction of the spire. Lines of growth running in a longitudinal direction from apex (shown in fig. 1). GENERAL STRUCTURE OF BODY — FIG. 3. SECTION OF BODY, shell and viscera removed — Parts of body — foot, mantle, visceral sac, pulmonary chamber. BUCCAL CAVITY / Eoof with horny ->aw- I Floor with odontophore (Gr. odmis, odontos, a tooth ; plioreo, I bear). CEsophagus. Rectum seen in section. Nervous ganglia seen in section above and below gullet. Columellar muscle attaching body to shell. FJC. 4. COMMON SNAIL with shell removed and covering of pulmonary chamber turned back — Heart consisting of auricle and ventricle. Blood-vessels ramifying in wall of pulmonary chamber. Renal organ or kidney for getting rid of nitrogenous waste. Pulmonary aperture leading into the modified mantle-cavity or pulmonary chamber, with anu« beside it. ALIMENTARY SYSTEM — FIG. 5 a. BUCCAL MASS removed from body — Protractor and retractor muscles. CEsophagus and duct of salivary gland leading from it. FIG. 5 b, and DIAG. 1. ODON'TOPHORE IN SECTION — Skeleton formed of cartilage (blue). Sub-radular membrane with its muscles (yellow). Radula (L. a scraper), the surface of sub-radular membrane beset with cuticular teeth (red). FIG. G— a. Horny upper jaw detached. 6. Teeth of radula arranged in transverse rows. Fio. 7. DISSECTION FROM DORSAL SURFACE, with organs gently separated and laid out — Buccal mass. Gullet dilating into crop. ALIMENTARY SYSTEM Salivary gland embracing crop. Stomach, with a pyloric cajcuni near liver. Liver, with coiled intestine embedded in it. CIRCULATORY SYSTEM / Ventricle (auricle not shown). | Aorta. RESPIRATORY SYSTEM . Pulmonary chamber, with blood-vessels on wall. RENAL ORGAN , . . Nephridium (Gr. nephroi, kidneys) or kidney for getting rid of nitrogenous waste. 34 Ovo-testis or hermaphrodite gland embedded in liver, consisting of tubes in which ova and spermatozoa are developed. The blind end of one of the tubes with its contained ova and sper- matozoa shown in fig. 12. Duct of ovo-testis. Albumen-gland forming an albuminous secretion. Vas deferens or duct for conveying spermatozoa, opening into penis. REPRODUCTIVE ORGANS \ ~ .-, , , . ,.. i Oviduct for conveying ova, ending in vagina. Spermatheca or receptaculum seminis (L. receptacle of the semen) opening into vagina. Penis with long flagellum (L. a whip), an eversible involution of the integument. Dart-sac eversible, with pointed dart ) ,. c, ., „ ., V peculiar to Snail family. Mucous glands J CIRCULATORY SYSTEM — DIAG. 2. COMPARATIVE VIEW OF CENTRES OF CIRCULATION in — a. Worm — Dorsal trunk with transverse vessels discharging into it. b. Anodon — Dorsal trunk dilated =the ventricle, and transverse vessels reduced to a pair forming the two auricles. c. Snail — Dorsal trunk bent upon itself =the ventricle sending blood to anterior end of body by cephalic artery, and to posterior end by abdominal artery. Transverse vessels reduced to one, the right, forming the auricle. FIG. 8. COLOURLESS CORPUSCLES OF THE BLOOD. NERVOUS SYSTEM AND SENSE ORGANS — FIG. 9. NERVOUS SYSTEM forming a ring round gullet — Cerebral or supra-oesophageal ganglia. „ , , T v f Pedal, anterior and united with cerebral by commissures. Sub-cesophageal ganglia {„.',,. .. , .., , , J ( Paneto-splanchnic united with cerebral by commissures. FIG. 10. EYES, a pair, placed at end of tentacles— Sclerot'ic (Gr. skleros, hard) passing into a cuticular cornea, Choroid, the pigmented layer. Optic nerve expanding into an outer retina, the fibres of which pass through the choroid to form an inner retina with rods and cones nearest the light. Vitreous humour (not shown). Lens. Cornea with a conjunctiva on its outer surface. FIG. 11. ORGANS OF HEARING, a pair close to pedal ganglia- Auditory canal. Sac containing fluid and otoliths. Auditory nerve from cerebral ganglia (not shown). DEVELOPMENT — DIAG. 3. EARLY STAGES OF DEVELOPMENT OF A VELIGEROUS GASTEROPOD, no evident velum in Snail- Ciliated velum, an expansion of the integument about the head. Foot developing, with operculum (L. a lid) upon it. Shell external. CLASSIFICATION — Sub-Kingdom — Mollusca. Natural Order — Odonto'phora, because it has a distinct head ; and an Odontophore. Genus — Helix (Gr. a spiral), from the spiral form of the univalve shell. Common Name — SnaiL EDIBLE FROG(RANA ESCULENTA) PLATE XVIII. Fig. I. E.-rf&tded' Frog dnrsai, aspect 2. Dissection/ from tfve^ ventral fuie. operusig {posterior surfiuie-J Diagram 2. Transverse Section of Verte brate & Inverte brate a. "Vertebrate, ~b Inverted rate- fywq Thnermost digit, \ * -t dorsal surface, l?& - Cerebro spinal, nervous system. Fi'6. 3. LorKjituxLaial, vertjucaL section,, with- *7ie part* laitL au&. (Female*! Bristle- Dossed, into Anterior Sb out' erf Posterior nosTriL „, \ BriffSje. pc^se&througJvTyrnpajuv cavity & !^ . 4-. AUmentcuy ituiul i Froy . W!tA-K.John«U.n. Edinburgh It Londo- 35 PLATE XVIII. THE FKOGK EXTERNAL CHARACTERS — FIG. 1. FROG with Limbs extended — Anterior nares or external nares (L. nares, the nostrils). Eye. Tympan'ic membrane or membrana tym'pani (L. tympanum, a drum). Cutaneous pouch (L. cutis, the skin). Clo'acal aperture (L. cloaca, a sewer). f Brachium (L. the arm). \ Antebrachium (L. ante, before). FORE-LIMB < Manug (L the hand). (_ Four digits (L. digitus, the finger or toe). f Femur (L. the thigh). HIND-LIMB \ C™ (L the leg). I Pes (L. the foot). V Five digits. GENERAL DISPOSITION OP INTERNAL ORGANS — FIG. 2. DISSECTION from the Ventral Surface to show VISCERA, Thoracic and Abdominal — w ( Ventricle. ' I Two auricles. Lungs, right and left. Stomach and intestine. Liver with gall-bladder, pancreas, and spleen. Urinary bladder. Corpus adiposum (L. fatty body), finger-like yellow processes, Testis, only one shown. DIAG. 1. TRANSVERSE SECTION THROUGH ABDOMEN — NEURAL CANAL containing Spinal cord. Lining membrane or pleuroperitoneal membrane (Gr. pleuron, a rib ; peri, around ; teino, I stretch). Alimentary canal suspended by two layers of the membrane coming together in the middle line — the PLEUROPERITONE'AL CAVITY = THORACIC CAVITY lined by the pleura, . and ABDOMINAL CAVITY lined by the \ peritoneum in Man. mes'entery (Gr. mesos, middle; enteron, intestine). Testes suspended in the same way by the mesorchium (Gr. orchis, a testicle). Kidneys held in place by the membrane covering their ventral faces. Sympathetic nervous system, two gangliated cords con- tained in triangular space formed by the layers of membrane converging to form mesentery. Dorsal aorta. DIAG. 2. COMPARISON OF A TRANSVERSE SECTION OF A VERTEBRATE (FROG) AND AN INVERTEBRATE (LOBSTER) — Invertebrate — Vertebrate — Visceral tube only. Visceral tuba Neural tube. Notochord (Gr. notos, the back ; chorde, a string), the primitive axial column, separating the two tubes. Limbs on neural or nerve side of body. Limbs on hasmal or heart side of body. 36 FIG. 3. TIIE LIMBS on the left side are removed, together with the left walls of the cerebro-spinal, thoraco-abdominal, and buccal cavities. The alimentary canal is laid out to display it to advantage — Mouth with posterior nostril, and Eustachian recess con- tinuous with tympanic cavity. Tongue turned forward to show its attachment. Teeth in upper jaw and on palate. Stomach. ALIMENTARY SYSTEM ( ?maU !ntestine 8ucceedinS stomach- Large intestine terminating in cloaca. Liver lobed. Pancreas or "sweetbread," pale coloured, near pyloric portion of stomach. Spleen, red, near the commencement of twisted portion of intestine. -. ( Dorsal aorta. ClKCULATOEY SYSTEM .... < T , . ( Inferior vena cava. EESPIRATORY SYSTEM I Glottis> a slit in floor of Phai7nx leadinS into lunga- ( Left lung. • I Eight ovary. I Oviduct, anterior coiled portion of right and terminal RENAL AND EEPEODUCTIVE SYSTEMS ( dilated portion of left (see PL XXII. fig. 8). j Left kidney with ureter. I Urinary bladder, bilobed. NERVOUS SYSTEM Brain and spinal cord. SKELETON Vert'ebral column enclosing spinal cord, and Skull enclosing brain. FIG. 4. ALIMENTARY CANAL removed from body — CEsopHAGDS or gullet communicating with pharynx. STOMACH / Cardiac or anterior portion. \ Pyloric portion leading into intestine. SMALL INTESTINE . j Duode'num forming a loop with the stomach. ( Ileum, the twisted portion (Gr. eilein, to twist). LAKGE INTESTINE f Colon, the dilated portion into which the ileum opens. ( Eectum (L. the seat) opening into cloaca. EDIBLE FROG (RANA ESCULENTA)— CONT"- PLATE XIX. Fi£. 3 StcuZl- lala-aL- viexv frort Fig S - Pro o&& - - — -~ skull- dorsal view sl&ntL - ventral- -»i»v. R}>i.n.al> process nasal process Vertebral cdww &: 13 Fare,~2irrib or O Diagram of Typical Vertebrate Limb Jffl>ia. & Fibula. flisuL toyeOur If. Hoid- harm, or Fig, 12. Jterraun Sc Shoulder -yi - Ventrai vi&v 1 Kbalnrt, Tanau >-- L , _l C W.S A.K JohoBion. Zdurtnirgh V L 37 PLATE XIX. THE "FROG— continued. SKELETON. %* The colours in left-hand corner of Plate refer only to Skull THE BONY SKULL — FIG. 1. DORSAL VIEW — Exoccipitals (L. ex, out ; occiput, the back of the head). Pro-otics (Gr. pro, in front of ; ous, otos, the ear). Parietals (L. paries, a wall) . . ) „ , /T ' , - , ,, >• united in adult. 1( rentals (L. frons, the forehead) ) Nasals. Premaxillae (L. prce, before ; maxilla, the upper jaw). FIG. 2. VENTRAL VIEW, lower jaw removed — Parasphen'oid (Gr. sphen, a wedge). Sphenethmoid or girdle-bone. Vomers with teeth. Premaxilke with teeth. Pterygoids (Gr. pteron, a wing). Palatines, slender palate bones. FIG. 3. SIDE VIEW — Squamosals. Quadrato-jugals. Maxillae with teeth. Premaxillae with teeth. Mandible or lower jaw, consisting of two rami (L. ramus, a branch) without teeth. ( Meckel's cartilage forming the core. RAMUS \ Anarulo-splenial . . ) . i Dentary without teeth j mvestlnS Meckels cartllaSc- V Mento-Meckelian bone (L. mentum, the chin), the ossified tip of Meckel's cartilage. Fro. 4. POSTERIOR VIEW — Exoccipitals with condyles (Gr. kondulos, a knuckle) for articulation with vertebral column. Foramen magnum (L. great opening), through which spinal cord passes into brain. THE CARTILAGINOUS SKULL — FIG. 5. DORSAL VIEW — Sphenethmoid bone, replacing cartilage and partly covered by the f rentals (see fig. 1). Nasal roof covered by nasals. Fontanelles, membranous portions. FIG. 6. VENTRAL VIEW — Sphenethmoid bone. Nasal floor anterior to Sphenethmoid covered by vomers. Floor posterior to Sphenethmoid from the exoccipitals covered by the parasphenoid, which partly overlaps Sphenethmoid. Pterygoid bar, replaced by pterygoid and palatine bones (see fig. 2). FIGS. 5, 6. MANDIBULAR SUSPENSORIUM, connecting lower jaw with skull- Posterior end articulating with Meckel's cartilage. Anterior end dividing J Dorsal process or eras attached to outer wall of skull into ( Ventral process or crus continuous with pterygoid bar. Note. — Two kinds of bone are distinguished in the skull according to their mode ol origin — 1. Cartilage bones (red), as the nunic denotes, are first modelled in cartilage. 2. Membrane or splint bones (blue) are those not so preformed in cartilage. 38 FIGS. 7, 8, 9. THE VERTEBRAL COLUMN or BACKBONE =9 bony segments or vertebrae and a bony prolongation or urostyle (Gr. oura, a tail) — ( Body or centrum. VERTEBRA . . . . < C Neural spine or spinous process. V. Neural arch •< Transverse processes. (. Zygapo'physes (Gr. zugos, an articulation). ATLAS or 1st vertebra with which the two occipital condyles of the skull articulate. SACRUM or 9th vertebra with which the pelvic girdle articulates. f Thickened anterior end with two concavities into which the two con- J vexities of the sacrum fit (fig. 9, a). UROSTYLE or COCCYX < gciatic nerve) the nerye of ^ ieg) passing out from neural canal by a (. small opening (red). FIG. 10. PELVIC AECH, side view — 'Acetab'ulum, the socket into which the head of the thigh-bone or femur fits. PELVIC ARCH or HIP- GIRDLE .... Ilium or haunch-bone articulating with sacrum. Ischium, a posterior rounded bone. Pubis, a ventral wedge between ilium and ischium. ^Triradiate junction of the three bones in the acetabulum. FIG. 11. HYOID — BODY. f Anterior attached to skull (see fig. 2). PROCESSES OK CORNUA J Lateral (L. horns) ... 1 Posterior. V Thyro-hyals, sometimes called posterior cornua. Fia. 12. STERNUM and SHOULDER-GIRDLE — STERNUM or BREAST- f Anterior piece— Omc-sternum (Gr. o»no», the shoulder), -j Median piece — Sternum proper. (. Posterior piece — Xiphi-sternum (Gr. xiphos, a sword). / Glenoidal cavity, the socket into which the head of the humerus fits. PECTORAL ARCH or \ Dorsal portion — Scapula or shoulder-blade, and Supra-scapula. SHOULDER-GIRDLE j „ ( Coracoids. f Ventral portions •< ™ . , ,, , V (. Clavicle or collar-bone. FIG. 13. RIGHT FORE-LIMB, dorsal surface — Humerus. Radius and ulna united. Carpals or wrist-bones. Five digits consisting of inetacarpals and phalanges (first digit rudimentary =Pollex, L. thumb). Fid. 14. LEFT HIND-LIMB, dorsal surface — Femur or thigh-bone. Tibia and fibula united. Tarsals with elongated astragalus and calcaneum. Five digits consisting of metatarsals and phalanges. Calcar (L. a spur), a horny projection at base of first digit or hallux (L. hallex, the big toe). DIAGRAM. THE CORRESPONDING BONES IN THE FORE AND HIND LIMBS WITH THEIR RESPECTIVE ARCHES — The axis (an imaginary line passing through the middle of the limb to the end of the third digit) divides the limb into a preaxial and a postaxial portion. Carpus or tarsus consists of two rows of bones with a centrale between, and the following are thus named in human anatomy : — Radiale = Scaphoid. Tibiale 1 , Intermedium = Lunar. Intermedium j = Ulnare =Cu'neiform. Fibulare =Calca'neum. Centrale, not represented. Centrale =Navicula're. EDIBLE FROG(RANA ESCULENTA)— PLATE XX. Fig. I. Arltrita vtntral Carotid/ trunk. al' Jugular to Btnal Reproductive' Organs &c Dia^. 2 TnaiCLut artenosus laid- opa -Ffsnoral Fjjg. 3 . Wet of foot, slujhtly enlaraed Arterie.-; -Lingual- artery ~ 'Carotid, Pubn&nary „ ~atvt in/ nght> .ride bit pariilzan. ,courye' of Cu*f illation. 6. Interior of Lung Cartilages of Laryn,-& . fc A K.Jdm-iott Eaonbutgh I London, 39 PLATE XX. THE — continued. CIRCULATORY SYSTEM — FIG. 1. ARTERIES — f Lingual artery (L. lingua, the tongue) to tongue. CAROT'ID TRUNK OR AN- J Carotid gland. TERIOE AORTIC ARCH ] Carotid artery to head by way of ear (Gr. kara, the head ; mis, the V ear). / Vertebral artery to vertebral column. Sub-clavian artery (L. sub, under; clavicula, collar-bone) to forelimb. (Esophageal artery to gullet. Cceliac artery ( Hepatic to liver. (Gr. Tcoilia, the belly) \ Gastric to stomach. ( Splenic to spleen. ( Haemal to intestine (not named). Dorsal aorta, giving off branches to various organs. Common iliac arteries formed by the forking of the aorta in the neighbourhood of the ilium, and giving off hypogastric branches to the bladder and lower parts of the belly. Femoral and sciatic arteries, a continuation of the common iliac down the thigh. AORTIC TRUNK OK MIDDLE AOETIO ARCH Mesenteric artery PULMO-CUTANEOUS TRUNK OR POS- TERIOR AORTIC AECH FIG. 2. VEINS — SUPERIOR VENA CAVA, FORMED BY INFERIOR VENA CAVA, FORMED BY J Pul'monary artery to lung (L. pulmo, a lung). } Cutaneous artery to the skin of the back (L. cutis, the skin). C Innominate, formed by / *nternal **&***• ( Sub-scapular. } Sub-clavian, formed by / Musculo-cutaneous. ( Brachial. ^ External jugular. f Eenal. •< Genital (not shown). (. Hepat'ic. COMMON ILIAC or EENAL AFFERENT VEIN formed by the dorsal ends of the pelvic vein, which is formed by the femoral and sciatic veins. Dorso-lumbar vein opens into common iliac. ANTERIOR ABDOMINAL VEIN formed by the ventral ends of the pelvic vein. f Gastric. PORTAL VEIN or VENA PORT.E (L. the vein of the gate — of the liver) formed by -| Lieno-intestinal (L. V lienis, the spleen). COMMON PULMONARY VEIN formed by the veins of the right and left lungs. DIAGRAM I. THE HEART, with the principal vessels distributing and returning the blood — f Sinus venosus (L. venous sinus) receiving superior and inferior venae cavae. HEART -^ Eight auricle with sinus venosus opening into it. I Left auricle receiving common pulmonary vein. L Ventricle leading into truncus arteriosus (L. arterial trunk). 40 f Carotid supplying the parts about the head, including the brain. PRINCIPAL AKTEEIAL TRUNKS j Pulmo-cutaneous supplying the lungs and dorsal integument. V. Aortic supplying the rest of the body. ^Superior cava returning blood from the head, forelimbs, and dorsal integument chiefly. Pulmonary veins returning blood from the lungs. Vena portse returning blood from the stomach, intestine, spleen PRINCIPAL VENOUS TRUNKS -^ and pancreas to liver. Anterior abdominal returning blood from the urinary bladder and belly-walls to liver. Inferior cava returning blood from the hind-limbs, kidneys, and liver chiefly. DIAGRAM II. TRUNCUS ARTEEIOSUS laid open to show action of heart Pylangium (Gr. pule, gate ; angeion, a vessel), or receiving part, contains a median longitudinal valve or movable partition attached to the dorsal surface, and a small transverse valve on the right side. Synangium (Gr. sun, together), or distributing terminal part, gives rise to Pulmo-cutaneous, Aortic, and Carotid trunks. FIGS. 3, 4. CIRCULATION OP THE BLOOD IN THE WEB — Arteries with flow of blood towards the smaller branches. Capillaries arising from the ultimate branches of the arteries and giving rise to the veins. Veins with flow of blood from smaller to larger vessels. Oval blood-corpuscles coursing through the vessels. Pigment-cells on the surface RESPIRATORY SYSTEM — FIGS. 5, 6. STRUCTURE AND FRAMEWORK of the Respiratory Organs — FIG. 5. Glottis (Gr. glotta, the tongue), a longitudinal slit opening into the floor of the back part of the mouth or pharynx (PL XVIII. Fig. 3). Arytenoid cartilages, one on each side of the glottis, movable inwards and outwards. Laryngo-tracheal cartilage, a ring forming the very short tube common to the two lungs. FIG. 6. The Lung is a thin-walled, elastic, and transparent bag, the inner surface of which shows shallow depressions produced by infoldings of the wall, and corresponding to the air- cells of higher animals. FIG. 7. MUSCLES of the throat for depressing and raising the floor of the mouth — inspiratory muscles. MUSCLES HAVING THEIR ( Mjlobyoid (Gr. mule, a mill), insertion in rami of mandible. "ORIGIN" IN ANTERIOR J Gemo-hyoid, insertion in symphysis of mandible or chin. PORTION OF HYOID / Hy°-gloss_lls (Gr- 9h** °"Sln ln SCaPula" PORTION OP HYOID . . j Stern°-hy°id> origin in sternum. NOTE.— The point of attachment comparatively fixed is called the Origin of the Muscle, while the attachment to the part to bo moved is called its Insertion. EDIBLE FROG(RANA ESCULENTA)— CONT»- PLATE Ft 4 . 1 . Bra Diag.l. 2ffrvmt* sysiem Crrtbrospuu vaibnl Fig.2. Jjong! vsrtiml nuiftan section Fig 4, Rrain & tptnal cord offirain roitraJ (,\v/ ~jf /--*"* raarielt- W 1 VJii \-Medalla. 0blongaiiL_ Principal' franial nervt* thf left, side, & err removed Foramen nt'llunrr, - Corrun — Central, ranal Oia4 2. Tnxntvtrst SetJion, at' Spinal Card * Neural ( Postrrun- arDorsal fLtflU'f maiir tirtiTia cavity ixjniinvu- inventing JjffutaJ- Card trunk' _^_ cfntrahf wifft epithelial Uning maltir ia^ 3 Ntrvea goinq fo Muse/or ar'tht Jltpertor Obuqut. J) of Thi'i/h &L Lea Suid Limb ^- ^*~j -Jfub™ ^~* ** '"-*^ J Antsrior'iw-l'rvnt .mrtut-f II Optic / .6. Ntrve* rf JKnd Ltntl 00, Ihl batt of tilt Hnq/l W 4.A.K JoTin.wn, EdAVur^h. ILondor 41 PLATE XXI. Jb JlxiOCjr — continued. NERVOUS SYSTEM — FIGS. 1, 2. THE BSAIN or ENCEPII'ALON (Gr. en, in ; kephale, the head) — /"Olfactory lobes or Khinenceph'alon (Gr. rhis, rhinos, the nose) giving off olfactory nerves. J Cerebral hemispheres or Prosenceph'alon (Gr. pros, before) completely 1 separated by the great fissure (fig. 3). I Optic thalami (Gr. thalamos, a bed), one on each side bounding the third ventricle with pineal gland on roof.=Tlialamenceph'alon. MID-BRAIN ( Optic lobes above and crura cerebri (L. legs of the cerebrum) below. = (Yellow) ( Mesenceph'alon (Gr. mews, middle). /"Cerebellum (L. the little brain), very small =Metenceph'aloii (Gr. me(a, J behind). I Medulla oblongata (L. elongated marrow) with the fourth ventricle. = V Myelonceph'alon (Gr. muelos, marrow). Lamina terminalis (L. terminal plate), the anterior wall of the thalameucephalon ter- minating the axial portion of the brain, the hemispheres being lateral expansions. FIG. 3. THE CAVITIES OF THE BRAIN, so-called Ventricles — 1. Olfactory. 2. Lateral . ) 3 Third vent ' •! (" Aperture °* communication, foramen of Munro. Iter a tertio ad quartum veiitriculurn (L. passage from third to fourth ventricle), with ventricles of optic lobes entering it. 4. Fourth ventricle, continuous with central canal of spinal cord. FIG. 4. GENERAL VIEW OF THE BRAIN AND SPINAL CORD, cerebro-spinal axis- Brain showing chiasma (Gr. a crossing) of the optic nerves, and optic tracts leading from optic lobes. Spinal cord or myelon, tapering away to the filuni terminate (L. terminal thread). DIAG. 1. Ten pair of CRANIAL NERVES, ten pair of SPINAL NERVES, and ten pair of SYMPATHETIC GANGLIA — CRANIAL NERVES, 1 to 10 (yellow). Spinal 1, hypoglossal (Gr. hupo, under ; glossa, a tongue), distributed to tongue. ,, 2 and 3, forming a brachial plexus (L. brackium, an arm; plexus, a junction), and distributed to fore-limbs. SPINAL NERVES (Blue) / „ 4, 5, and 6, distributed to the body-walls. „ 7, 8, and 9, forming a lumbo-sacral plexus (L. lumbiis, the loin). and distributed to posterior portion of body and hind-limbs ; crural to front of limb and sciatic (contraction for ischiatic) to back of it. 10, distributed to parts about coccyx. SYMPATHETIC GANGLIA (S. 1 to S. 10), with connecting commissures (red). DIAG. 2. CONTENTS OF NEURAL CANAL, as seen in a transverse section — rGrey matter, a central square with its four corners passing into the posterior (dorsal) and anterior (ventral) roots of the nerve-trunk. SPINAL CORD •{ Central canal lined with epithelium. I White matter outside grey matter { Posterior fiarare (dorsal) L ( Anterior hssure (ventral). 9 42 fPia mater, a vascular membrane investing cord and continuous with MEMBRANES USING I Dura mater Hning canal ^ L.ANAI, ANI IN-S Arachnoid superficial to pia mater and dura mater, and secreting arachnoid VESTING CORD L fluid (blue). FIG. 5 and DIAG. 3. CRANIAL NERVES, and their distribution — I. Olfactory (L. oleo, I smell) distributed to olfactory sac, as shown in Diag. 1. II. Optic distributed to eye (Diag. 3). III. Oculo-motor (L. oculus, eye ; motor, mover) distributed to four muscles of eye (Diag. 3). IV. Pathetic distributed to superior oblique muscle (Diag. 3). V. Trigeminal dilates into Gasserian ganglion giving off — V1. Orbito-nasal or ophthalmic distributed chiefly to the nasal chamber. Vs. Superior maxillary distributed to upper jaw. V3. Inferior maxillary or mandibular distributed to lower jaw or mandible. VI. Abducens (L. abduco, I draw away) distributed to external rectus muscle (Diag. 3). VII. Facial or portio dura (blue) dividing at Gasserian ganglion into — VII". Or anterior distributed chiefly to the palate. VIP. Or posterior dividing into a branch to the hyoid and a branch to mandible by way of tympanic cavity = chorda tympani (L. cord of the drum). VIII. Auditory or portio mollis distributed to the auditory capsule (Diag. 1). IX. Glossopharynge'al (Gr. glossa, the tongue ; pluirunx, the throat) distributed to tongue and pharynx (yellow). X. Pueuinogastric (Gr. pneumon, the lungs; gaster, the stomach) or Vagus (L. wandering) (red) — X1. Cutaneous branch distributed to dorsal integument. X2. Cardiac branch distributed to heart. X3. Laryngeal branch distributed to larynx. X*. Pulmouic branch distributed to lungs. X5. Gastric branch distributed to gullet and stomach. FIG. 6. NERVES OF HIND-LIMB, bones displaced to show nerves of dorsal surface — SCIATIC / Perone'al (Gr. perone, the fibula) running beside peroneus muscle. I Posterior tibial running beside tibialis posticus muscle. MUSCULAR SYSTEM— DIAG. 3. MUSCLES OF EYE. FIG. 7. SUPERFICIAL MUSCLES OF HIND-LIMB. Frog dissected when laid on back, with dorsal surface of foot uppermost. Name. Origin. Insertion. Adductores — brevis, maguus, and Pelvis. Femur. longus. Sartorius. TIIIGH LEG Rectus interims major. Rectus internus minor. Vastus internus. ( Gastrocnemius, the bulk of the calf of the leg (Gr. yaster, the belly; kneme, the leg). Tibialis posticus (L. posterior tibial). Perone'us, Tibialis anticus (L. anterior tibial). Extensor cruris bre?is (L. short extender of the leg). Flexor tarsi anterior (L. anterior bender of the tarsus). Pubis. Pubis. Pelvis. Pelvis, near to hip-joint. Partly fomur, partly cms. Cms. Femur. Femur. Femur. Femur. Crus, inner side of knee-joint. Do. Do. Do. Ending in tendo Achillis. Astragalus, Calcaneum. Astragalus and calcaneum. Crus. Astragalus. 43 Name. Origin. Fi». 8. DKEP MUSCLES on front or ventral surface of thigh — Pectin'eus. Pelvis. Adductor brevis, also seen on surface. Semitendinosus. Pelvis. Vastus internns, also seen on surface. FIG. 9. MUSCLES on back of thigh — for dissection lay out as in PL XVIII. fig. 1-- { Vastus internus. ~~| Itectus femoris , anticus (not /• Pelvis. v I shown). Vastus externus. J Glutse'us (Gr. (/loutos, the buttock). Pelvis. Pyriformis. Urostyle. Biceps femoris (L. biceps, having two heads). Pelvis. Semimembranosus. Pelvis. Rectus internus, seen also on front. Insertion. Femur. Crus. Crus. Femur. Femur. Femur. Crus and femur, round knee-joint. EDIBLE FROG (RANA ESCULENTA)— PLATE XX1L F14.2 Atfaary region si J ~ Fit. 4. Essential farts at* Hitman Ear Fi*.8 Jtenal & Reproductive organs &, Reprodu£tixes organs (Male*} Ftfc.lO Section -of UrinJf'fTdus Tubule. Fifc.lZ Ovum of ROTLOJ ttmpoj-aria; K RJI3 TaJpoU.si farther advanced; — SucJws -j Rudiment, &f- JKndf- larib ~\-n Tadpole* fftad; enlarged' sid& 1 ^Pp-w fy> ---. £&vm*i*£>