The Comparative Anatomy ClipArt gallery offers 227 images of anatomy comparing numerous parts of humans and animals, showing similarities and differences among species and between different taxonomic orders.

"The origin of the mesonephric tubules is seen. They arise from the upper part of the lateral plate, which is now completely separated from the primitive segment, and curving round the pronephric duct come to open into it.n.c., nerve cord; nch., notochord; pn., pronephros; g., gut; p.s., primitive segment; mes., mesonephric tubule; pn.d., pronephric duct; b.c., body cavity; ao., aorta; siv., sub-intestinal vein, with vessel to the aorta." -Thomson, 1916

Excretory System Stage 3

"The origin of the mesonephric tubules is seen. They arise from the upper part of the lateral plate,…

Eye of the phalaena or butterfly, magnified, consisting of 11,300 square sections. The eye of the mordella is similar, containing 25,088 prisms.

Eye of the Butterfly

Eye of the phalaena or butterfly, magnified, consisting of 11,300 square sections. The eye of the mordella…

Eye of the yellow beetle magnified, composed of 8,820 hexagonal cylinders, the interior of each tube being round.

Eye of the Yellow Beetle

Eye of the yellow beetle magnified, composed of 8,820 hexagonal cylinders, the interior of each tube…

"Diagram of the principal vessels in the circulation of a Fish, lateral view. a, aorta; au., auricle; br.a., afferent branchial arteries; br.e., efferent branchial arteries; bu., bulbus (or conus) arteriosus; c, carotid; c.a., caudal artery; c.v.r., right cardinal vein; c.v.l., left cardinal vein; d.a., dorsal artery; d.c., ductus Cuvieri; g, gills; h.v., hepatic vein; h.p., hepatic portal vein; i, intestine; j, jugular vein; k, kidney; l, liver; r.p., renal portal vein; s.v., sinus venosus; v, ventricle." -Galloway, 1915

Fish Circulation Vessels

"Diagram of the principal vessels in the circulation of a Fish, lateral view. a, aorta; au., auricle;…

This figure shows the mode of respiration in fishes. The gills are seen bent over in the form of a feather. Labels: d, the auricle of the heart; e, the ventricle; f, the bronchial artery; g,g, the gills.

Respiration in Fishes

This figure shows the mode of respiration in fishes. The gills are seen bent over in the form of a feather.…

"Salmo fario, the entire skull, from the left side. art, articular; branchiost, branchiostegal rays; dent, dentary; epiot, epiotic; eth, supra-ethnoid; fr, frontal; hyom, hyomandibular; intop, inter-opercular; pal, palantine; par, parietal; pmx, pre-maxilla; praop, pre-opercular; pt, pterygoid; pter, pterotic; Quad, quadrate; socc, supra-occipital; sphot, sphenotic; subop, sub-opercular; sympl, symplectic; Zunge, basi-hyal." -Parker, 1900

Fish Skull

"Salmo fario, the entire skull, from the left side. art, articular; branchiost, branchiostegal rays;…

"Diagram of vertebrae of a bony fish. A, caudal; B, trunk. c, centrum or body of the vertebra; ch., the notochord; h.a., haemal arch; h.c., haemal canal; h.s., haemal spine; h.z., haemal zygapophysis, or articulating facet; m.b., inter-muscular bone; n.a., neural arch; n.c., neural canal; n.s., neural spine; n.z., neural zygapophysis; r, rib." -Galloway, 1915

Fish Vertebrae

"Diagram of vertebrae of a bony fish. A, caudal; B, trunk. c, centrum or body of the vertebra; ch.,…

Generic development of the horse's foot. A, Foot of Eohippus; B, That of Orohippus; C, That of Hipparion; D, that of horse. The digits are numbered, when present, I. to V.

Evolution of Horse Foot

Generic development of the horse's foot. A, Foot of Eohippus; B, That of Orohippus; C, That of Hipparion;…

Two cross sections through the forebrain. A. Through the forebrain of the early human embryo. B. Through the forebrain and optic vesicles of Lepidosteus embryo of eight days.

Section Through Forebrain of Human and Lepidosteus Embryos

Two cross sections through the forebrain. A. Through the forebrain of the early human embryo. B. Through…

"Diagram of a longitudinal section through the embryo of a fowl, showing formation of amnion and allantois and the relation of these membranes to the embryo. am1, inner or true amnion; am2, outer or false amnion; am.c., amniotic cavity; al., allantois; c.c., central canal of the spinal cord; co., coelom; g, gut; ys., yolk sac." -Galloway, 1915

Fowl Embryo

"Diagram of a longitudinal section through the embryo of a fowl, showing formation of amnion and allantois…

"Diagram of the stomach and esophagus of the fowl. o, esophagus; c, crop; p, proventriculus or glandular stomach; g, gizzard or grinding stomach; i, intestine." -Galloway, 1915

Fowl Stomach

"Diagram of the stomach and esophagus of the fowl. o, esophagus; c, crop; p, proventriculus or glandular…

"Arterial system of frog. l., Lingual; c., carotid; s., systemic; cu., cutaneous; p., pulmonary; v., occipito-vertebral; br., brachial; c.m., coeliaco-mesenteric; r., renal; il., common iliacs; h., haemorrhoidal." -Thomson, 1916

Frog Arterial System

"Arterial system of frog. l., Lingual; c., carotid; s., systemic; cu., cutaneous; p., pulmonary; v.,…

Blood corpuscles of a frog. Highly magnified. The appearance of blood cells in different animals varies in shape and size.

Frog Blood Corpuscles

Blood corpuscles of a frog. Highly magnified. The appearance of blood cells in different animals varies…

"Rana esculenta. The brain. A, from above; B, from below. ch. opt, optic chiasma; HH, cerebellum; Hyp, pituitary body; Inf, infundibulum; L. ol, olfactory lobe; Med, spinal cord; MH, mid-brain; NH, medulla oblongata; Th. opt, optic thalamus; Tr. opt, optic tract; VH, cerebral hemisphere; ZH, diencephalon; I-X, cerebral nerves; XII. (1), hypoglossal (first spinal) nerve." -Parker, 1900

Edible Frog Brain

"Rana esculenta. The brain. A, from above; B, from below. ch. opt, optic chiasma; HH, cerebellum; Hyp,…

"Rana esculenta. Urinogenital organs of the female. N, kidneys; Od, oviduct; Ot, its coelomic aperture; Ov, left ovary (the right is removed); P, cloacal aperture of oviduct; S.S', cloacal apertures of ureters; Ut, uterine dilatation of oviduct." -Parker, 1900

Female Edible Frog Genital Organs

"Rana esculenta. Urinogenital organs of the female. N, kidneys; Od, oviduct; Ot, its coelomic aperture;…

"Rana esculenta. Urinogenital organs of the male. Ao, dorsal aorta; Cl, cloaca; Cv, post-caval vein; FK, fat bodies; HO, testes; N, kidneys; S, apertures of ureters into cloaca; Ur, ureters." -Parker, 1900

Male Edible Frog Genital Organs

"Rana esculenta. Urinogenital organs of the male. Ao, dorsal aorta; Cl, cloaca; Cv, post-caval vein;…

"Diagram of the heart and branchial arches in the Frog. c.g., carotid gland; l., lungs; l.a., left auricle; r.a., right auricle...a, aorta; au., auricle; c, carotid; c.v., cardinal veins (right and left); d.a., dorsal arteries; j, jugular veins; d.c., ductus Cuvieri; s.v., sinus venosus; v, ventricle." -Galloway, 1915

Frog Heart

"Diagram of the heart and branchial arches in the Frog. c.g., carotid gland; l., lungs; l.a., left auricle;…

"Nervous system of frog. 1-10, The cranial nerves; oc., eyes; crb., in front of optic chiasma; to., optic tract; sym., sympathetic system; msp., spinal cord; sp., spinal nerves." -Thomson, 1916

Frog Nervous System

"Nervous system of frog. 1-10, The cranial nerves; oc., eyes; crb., in front of optic chiasma; to.,…

"Pectoral girdle of Rana esculenta. The cartilaginous parts are dotted. Ep., Episternum; om., omosternum; Ep.c., Epicoracoids; st., sternum; x., xiphisternum; cl., clavicle with underlying precoracoid cartilage; co., coracoid; Sc., scapula; S.sc., supra-scapula; Gl., glenoid cavity for humerus." -Thomson, 1916

Frog Pectoral Girdle

"Pectoral girdle of Rana esculenta. The cartilaginous parts are dotted. Ep., Episternum; om., omosternum;…

"Rana esculenta. Pelvic girdle from the right side. G, acetabulum; Il, P, ilium; Is, ischium; Kn, pubis." -Parker, 1900

Edible Frog Pelvic Girdle

"Rana esculenta. Pelvic girdle from the right side. G, acetabulum; Il, P, ilium; Is, ischium; Kn, pubis."…

"Rana esculenta. The shoulder girdle from the ventral aspect. Co, coracoid; Co', epicoracoid; Cl, clavicle; G, glenoid cavity; Ep, episternum; Fe, fenestra between procoracoid and coracoid; KC, cartilage separating scapula and clavicle; Kn, xiphisternum; m, junction of epicoracoids; S, scapula; St, sternum." -Parker, 1900

Edible Frog Shoulder Girdle

"Rana esculenta. The shoulder girdle from the ventral aspect. Co, coracoid; Co', epicoracoid; Cl, clavicle;…

"Skeleton of frog. The half of the pectoral girdle, and fore- and hind-limb of the right side are not shown. pmx., premaxilla; m.x., maxilla; n., nasal; sph., sphenethmoid; p.f., parieto-frontal; P.O., pro-otic; pt., pterygoid; q.j., quadrato-jugal; sq., squamosal; Q., quadrate; c., columella auris; A., atlas; t.p., transverse process; S.V., sacral vertebra; U., urostyle; S.sc., supra scapula; H., humerus; R.U., radio ulna; Cp., carpals; Mc., metacarpals; Il., ilium; Is., ischium; F., femur; T.F., tibio-fibula; Ca., calcaneum; As., astragalus; C., calcar; Mt., metatarsals." -Thomson, 1916

Frog Skeleton

"Skeleton of frog. The half of the pectoral girdle, and fore- and hind-limb of the right side are not…

"Skull of frog. Lower surface-- Pmx., premaxilla; M., maxilla; Q.j., quadrato-jugal; Q., quadrate; Pt., pterygoid; Ps., parasphenoid; P.O., pro-otic; Sp.E., sphenethmoid; Pl., palatine; V., vomer; c., columella." -Thomson, 1916

Lower Surface of Frog Skull

"Skull of frog. Lower surface-- Pmx., premaxilla; M., maxilla; Q.j., quadrato-jugal; Q., quadrate; Pt.,…

"Skull of frog. Upper surface-- Pmx., premaxilla; N., nasal; M., maxilla; Sq., squamosal; Q.j., quadrato-jugal; e.o., ex-occipitals; P.f., parieto-frontals; Sph.E., sphenethmoid; P.O., pro-otic." -Thomson, 1916

Upper Surface of Frog Skull

"Skull of frog. Upper surface-- Pmx., premaxilla; N., nasal; M., maxilla; Sq., squamosal; Q.j., quadrato-jugal;…

"Venous system of frog. m., l., Mandibular and lingual; e.j., external jugular; i.j., internal jugular; scp., subscapular; in., innominate; scl., subclavian; br., brachial; m.c., musculo-cutaneous; h.v., hepatic vein; h.p., hepatic portal; a.a., anterior abdominal; r.p., renal-portal; p.v., pelvic; sc., sciatic; f., femoral; i.v.c., inferior vena cava; c., cardiac vein." -Thomson, 1916

Frog Venous System

"Venous system of frog. m., l., Mandibular and lingual; e.j., external jugular; i.j., internal jugular;…

"General view of the viscera of a male frog, from the right side. a, stomach; b, urinary bladder; c, small intestine; cl, cloacal aperture; d, large intestine; e, liver; f, bile duct; g, gall bladder; h, spleen; i, lung; k, larynx; l, fat body; m, testis; n, ureter; o, kidney; p, pancreas; s, cerebral hemisphere; sp, spinal cord; t, tongue; u, auricle; ur, urostyle; v, ventricle; v.s, vesicula seminalis; w, optic lobe; x, cerebellum; y, Eustachian recess; z, nasal sac." -Parker, 1900

Frog Viscera

"General view of the viscera of a male frog, from the right side. a, stomach; b, urinary bladder; c,…

The circulation of the blood in the web of a frog's foot. A, an artery; B, capillaries crowded with disks, owing to a rupture just above, where the disks are jammed into an adjacent mesh; C, a deeper vein; the black spots are pigments cells.

Circulation of Blood in a Frog's Foot

The circulation of the blood in the web of a frog's foot. A, an artery; B, capillaries crowded with…

"Skeleton of male gorilla. cl., Clavicle; sc., tip of scapula; S., praesternum; H., humerus; r., radius; u., ulna; Il., ilium; C., coccyx; P., pubis; Is., ischium; F., femur; t., tibia; f., fibula." -Thomson, 1916

Gorilla Skeleton

"Skeleton of male gorilla. cl., Clavicle; sc., tip of scapula; S., praesternum; H., humerus; r., radius;…

"Median longitudinal section of anterior region of Myxine. B., Barbule; N., nasal aperture; NT., nasal tube with rings of cartilage; NC., nasal capsule; BR., brain; SC., spinal cord; N., notochord; G., gut; T., cartilage of "tongue"; MU., muscle; NTT., posterior part of nasal sac; TP., a tooth plate; MT., median tooth on roof of mouth (M.)." -Thomson, 1916

Hagfish Anterior

"Median longitudinal section of anterior region of Myxine. B., Barbule; N., nasal aperture; NT., nasal…

"Respiratory system of hag, from ventral surface. b., Barbules; m., mouth opening on ventral surface; g., gullet; g.p'., first gill-pouch, cut open to show internal lamellae; g.p.6, sixth gill-pouch; v., ventricle of heart; ao., aorta; a., common exhalant aperture." -Thomson, 1916

Hagfish Respiratory System

"Respiratory system of hag, from ventral surface. b., Barbules; m., mouth opening on ventral surface;…

A comparison of vertebrate hands. A, hand or anterior foot of the dog; B, that of the hog; C, that of the elk; D, that of the ox. Digits: I, pollex; II, index; III, medius; IV, annukus; V, minimus.

Hands of Vertebrates

A comparison of vertebrate hands. A, hand or anterior foot of the dog; B, that of the hog; C, that of…

In high orders of Mollusca the circulation resembles that of fish. Shown is the heart and arteries of a snail. Labels: 2, The stomach. 3, Intestines. 5, Heart. 6, Aorta. 7, Pulmonary artery.

The Heart and Arteries of a Snail

In high orders of Mollusca the circulation resembles that of fish. Shown is the heart and arteries of…

"Hesperornis. ST., Sternum; CO., coracoid; CL., clavicle; H., rudimentary humerus; SC., scapula; P., pectineal pubic process; IL., ilim; IS., ischium; P.P., post-pubis; C.T., crest of tibia; F. fibula; T.T., base tibio-tarsus; T.M.T., tarso-metatarsus." -Thomson, 1916

Hesperornis Skeleton

"Hesperornis. ST., Sternum; CO., coracoid; CL., clavicle; H., rudimentary humerus; SC., scapula; P.,…

"Feet of horse and its predecessors. 1, Palaeotherium; 2, Anchitherium; 3, Hippotherium; 4, Equus." -Thomson, 1916

Horse Feet

"Feet of horse and its predecessors. 1, Palaeotherium; 2, Anchitherium; 3, Hippotherium; 4, Equus."…

"Side view of horse's skull. P., Parietal; FR., frontal; NA., nasal; PMX., premaxilla; MX., maxilla; J., jugal; L., lachrymal; SQ., squamosal; PP., paroccipital process; CO., condyle CA., canine." -Thomson, 1916

Horse Skull

"Side view of horse's skull. P., Parietal; FR., frontal; NA., nasal; PMX., premaxilla; MX., maxilla;…

A freshwater hydra, magnified. Example of an animal with no skeleton. There are animals without a skeleton that are not able to accomplish very powerful motions. Mot of them live in water where they are partly or wholly held up by the water and have only slow motions. Most are also very small and generally have no muscles.

Freshwater Hydra

A freshwater hydra, magnified. Example of an animal with no skeleton. There are animals without a skeleton…

A magnified view of a small portion of the surface of an insect's compound eye which is composed of little eye-tubes.

Eye of an Insect

A magnified view of a small portion of the surface of an insect's compound eye which is composed of…

Internal ear of different vertebrates. I, fish; II, bird; III, mammal. Labels: U, utriculus with semicircular canals; S, sacculus; US, utriculus and sacculus; C, cochlear duct; L, lagena; Cr, canalis reuniens; R, recessus vestibuli.

Internal Ear of Vertebrates

Internal ear of different vertebrates. I, fish; II, bird; III, mammal. Labels: U, utriculus with semicircular…

"Diagrams showing some of the stages in the increasing complexity of the simple eye in Invertebrates. A, simple pigment spot in epithelium having nerve-endings associated with pigment cells (as in some medusae); B, pigment cells in a pit-like depression (as in Patella); C, with pin-hole opening and vitreous humor in cavity (as in Trochus); D, completely closed pit, with lens and cornea (as in Triton and many other Mollusks); E, pigment area elevated instead of depressed, lens of thickened cuticula (as in the Medusa, Lizzia); F, retinal cells more highly magnified. ep., epidermis; f, nerve fibre; l, lens; op, optic nerve; p, pigment cells; r, retina; v.h., vitreous humor." -Galloway, 1915

Invertebrate Simple Eye

"Diagrams showing some of the stages in the increasing complexity of the simple eye in Invertebrates.…

"Foot of young kangaroo. 2, 3, Small syndactylous toes; 4, large fourth toe; 5, fifth toe." -Thomson, 1916

Kangaroo Foot

"Foot of young kangaroo. 2, 3, Small syndactylous toes; 4, large fourth toe; 5, fifth toe." -Thomson,…

The dissection of a female sea lamprey or Petromyzon marinus. ad, anterior dorsal cartilage; an, annular cartilage; au, auricle; bd, bile-duct; bp', basal plate; br, brain; cd, cardinal vein; d.ao, dorsal aorta; dm, dorsal muscles; ea, external gill aperture; ft, fibrous tissue; gr, groove canal; hp, basal plate to fontanelle; hv, hepatic vein; i, integument; i.ju; inferior jugular vein; int, intestine; ju, jugular; lg, lingual cartilage; lr, liver; m, buccal vavity; mv, median ventral cartilage; my, spinal cord; na, olfactory sac; na', pituitary pouch; na'', nasal aperture; na.c, nasal capsule; nc, notochord; n.ca, spinal canal; oc, cranial roof; oes, gullet; o.f, buccal funnel; ov, ovary; pc, pericardium; pd, posterior dorsal cartilage; pmt, protractor muscle of tongue; rmt; retractor of tongue; rt, respiratory tube; ss, lymph sinus; sv, sinus venosus; t, tongue; v, ventricle; v.ao, ventral aorta; vl, velum; vm, ventral muscles. -Parker, 1900

Lamprey Anatomy

The dissection of a female sea lamprey or Petromyzon marinus. ad, anterior dorsal cartilage; an, annular…

"The central nervous system in a leech. g, dorsal ganglia (brain); g', ventral chain of ganglia; o, mouth." -Galloway, 1915

Leech Nervous System

"The central nervous system in a leech. g, dorsal ganglia (brain); g', ventral chain of ganglia; o,…

A lobule of a pig liver, magnified, showing the hepatic cells radially arranged around the central intralobular vein, and the connective tissue surrounding the lobule.

Liver Lobule of a Pig

A lobule of a pig liver, magnified, showing the hepatic cells radially arranged around the central intralobular…

"Heart of monitor (Varanus) dissected to show the cavity of the ventricle and the vessels leading out from it. A. A', auricles; Ao, dorsal aorta; Ap. Ap', pulmonary arteries; Asc, subclavian artery; Ca. Ca', carotids; RA. RA, roots of dorsal aorta; Trca, innominate trunk; V, ventricle; +, right aortic arch; *, left aortic arch." -Parker, 1900

Monitor Lizard Heart

"Heart of monitor (Varanus) dissected to show the cavity of the ventricle and the vessels leading out…

Nerve ending in muscular fiber of a lizard (Kühne). The end-plate, or motorial ending of the axone, is seen sideways.

Nerve Ending in Muscle Fiber of Lizard

Nerve ending in muscular fiber of a lizard (Kühne). The end-plate, or motorial ending of the axone,…

"Side view of skull of Lacerta. px., Premaxilla; mx., maxilla; l., lachrymal; j., jugal; t.pa., transpalatine; epg., epipterygoid; pg., pterygoid; bpg., basipterygoid; b.o., basioccipital; q., quadrate; oc.c., occipital condyle; sq., squamosal; pr.o., pro-otic; pt.o., postorbital; st.1, st.2, supratemporals; ps., presphenoid (the optic nerve is seen issuing in front of the end of the reference line); p.e., mesethmoid; s.ob., supraorbitals; pf., prefrontal; n., nasal; ar., articular; ag., angular; sag., surangular; cr., coranary; d., dentary." -Thomson, 1916

Lizard Skull

"Side view of skull of Lacerta. px., Premaxilla; mx., maxilla; l., lachrymal; j., jugal; t.pa., transpalatine;…

"Lacerta agilis. General view of the viscera in their naturaal relations. Bl, urinary bladder; Ci, post-caval vein; ED, rectum; GB, gall-bladder; H, heart; Lg, Lg', the lungs; M, stomach; MD, small intestine; Oe, oesophagus; Pn, pancreas; Tr, trachea." -Parker, 1900

Sand Lizard Viscera

"Lacerta agilis. General view of the viscera in their naturaal relations. Bl, urinary bladder; Ci, post-caval…

"Appendages of Norway lobster. Ex., Exopodite: En., endopodite; protopodite dark throughout; Ep., epipodite. 1. Antennule--E., position of ear; 2., antenna--K., opening of kidney; 3. mandible--P., palp; 4. first maxilla; 5. second maxilla--B., baler; 6. first maxillipede; 7. second maxillipede; 8. third maxillipede--the basal joint of the protopodite is called coxopodite, the next basipodite; the five joints of the endopodite are called--ischiopodite (i.); meropodite (m.); carpopodite (c.); propodite (p.); dactylopodite (d.); 9. forceps--(7) coxopodite; (6) basipodite, the joints of the endopodite are numbered; 10-13. walking legs; 14. modified male appendage; 15-18. small swimmerets; 19. large paddles." -Thomson, 1916

Norway Lobster Appendages

"Appendages of Norway lobster. Ex., Exopodite: En., endopodite; protopodite dark throughout; Ep., epipodite.…

"An ommatidium or eye-element from the eye of the Lobster. c, cornea (cuticle); c.h., corneal hypodermis, which secretes the cuticle; co., cone cells; cr., crystalline cone; n, nuclei; n.f., nerve fibres; r.d., distal or outer retinula cells; r.p., proximal or inner retinula cells; rh., rhabdome." -Galloway, 1915

Lobster Ommatidium

"An ommatidium or eye-element from the eye of the Lobster. c, cornea (cuticle); c.h., corneal hypodermis,…

"Longitudinal section of lobster, showing some of the organs. H., Heart; AO., ophthalmic artery; SA., superior abdominal artery; MG., mid-gut; DG., digestive gland; HG., hind-gut; Ex., extensor muscles of he tail; Fl., flexor muscles of the tail; IA., inferior abdominal artery; G., gizzard; C., cerebral ganglia; P., pericardium; T., testes." -Thomson, 1916

Lobster Organs

"Longitudinal section of lobster, showing some of the organs. H., Heart; AO., ophthalmic artery; SA.,…

"Skeleton of Ceratodus fin. a., Central axis; r., radials; h., basal piece." -Thomson, 1916

Queensland Lungfish Fin

"Skeleton of Ceratodus fin. a., Central axis; r., radials; h., basal piece." -Thomson, 1916

"Head region of Protopterus. sn.t., Sensory tubes; l.l., lateral line; e.br., external gills; pc.l., pectoral fin; op., operculum." -Thomson, 1916

African Lungfish Head

"Head region of Protopterus. sn.t., Sensory tubes; l.l., lateral line; e.br., external gills; pc.l.,…

"Diagram of the heart and branchial arches in Protopterus (one of the Dipno). pre.c., precaval vein, made up of right and left jugulairs, subclavians, etc.; post.c., postcaval, made up the cardinals, right and left...a, aorta; au., auricle; c, carotid; c.v., cardinal veins (right and left); d.a., dorsal arteries; j, jugular veins; d.c., ductus Cuvieri; s.v., sinus venosus; v, ventricle." -Galloway, 1915

African Lungfish Heart

"Diagram of the heart and branchial arches in Protopterus (one of the Dipno). pre.c., precaval vein,…

"Diagram of heart and branchial arches in Ceratodus (one of the Dipnoi). a.b., air bladder (lung); p.a., pulmonary artery; p.c., post caval vein (right); p.v., pulmonary vein...a, aorta; au., auricle; c, carotid; c.v., cardinal veins (right and left); d.a., dorsal arteries; j, jugular veins; d.c., ductus Cuvieri; s.v., sinus venosus; v, ventricle." -Galloway, 1915

Queensland Lungfish Heart

"Diagram of heart and branchial arches in Ceratodus (one of the Dipnoi). a.b., air bladder (lung); p.a.,…

"Vertical section through backbone and ribs of Chelonian (I.) and Mammal (II.). N.SP., neural spine; N.SC., neural scute; T., tubercle of rib; C.SC., costal scute over rib (R.); CA., capitulum of rib; T.P., transverse process; CE., centrum; NA., cavity of neural canal. In the Chelonian the tubercle abuts against the flattened neural spine, and the capitulum against the transverse process. In the Mammal, the tubercle articulates with the transverse process and the capitulum with the centrum." -Thomson, 1916

Mammal and Chelonian Backbones

"Vertical section through backbone and ribs of Chelonian (I.) and Mammal (II.). N.SP., neural spine;…

"Diagram of foetal membranes. E., Embryo; H., gut lined by hypoblast, dotted-- the dark is mesoblast; UV., umbilical vesicle or yolk-sac; AC., amniotic cavity; am., amnion proper; sz., subzonal membrane; ALC., allantoic cavity; al., allantois; zp., may be here taken to represent the early epiblastic trophoblast. The figure does not show that the amnion folds consist of both epiblast and mesoblast." -Thomson, 1916

Mammal Fetus

"Diagram of foetal membranes. E., Embryo; H., gut lined by hypoblast, dotted-- the dark is mesoblast;…

"Diagram of the heart and the branchial arches in Mammals. A dotted outline of the arches of the Fish is drawn for ready comparison. The auricles are represented in a posterior position...a, aorta; au., auricle; c, carotid; d.a., dorsal arteries; j, jugular veins; s.v., sinus venosus; v, ventricle." -Galloway, 1915

Mammal Heart

"Diagram of the heart and the branchial arches in Mammals. A dotted outline of the arches of the Fish…

This is a diagram of the skin of mammals, showing the multiple layered condition, together with outgrowths and ingrowths. E, epidermis; D, dermis; a, adipose tissue, -fat deposited amid the connective tissue; b, blood vessels; c.e., columnar epithelial layer of the epidermis; f, hair follicle; g, hair; n, nerve; n.e., nerve ending; p, pore of sweat gland; seb., sebaceous or oil gland of hair; s.g., sweat gland; s.c., horny layer of epidermis; s.m., mucous layer of epidermis.

Mammal Skin

This is a diagram of the skin of mammals, showing the multiple layered condition, together with outgrowths…

This illustration shows the skeletons of Anthropid Apes compared with that of Man.

Man and Ape Skeletons

This illustration shows the skeletons of Anthropid Apes compared with that of Man.

The molar teeth of a human, horse and dog. The first image to the left in a molar tooth of a horse. Labels: 1, The enamel. 2, The ivory. 3, Canals for blood vessels. The center image is a molar tooth of a human. Label: 1, The enamel. 2, The ivory. 3, The cavity containing blood vessels. 4, 5, Artery and nerve. The image on the right is a molar tooth of a dog. Labels: 1, The enamel. 2, The ivory. 3, Cavity for blood-vessels.

Comparison of the Molar Teeth of a Human, Horse, and Dog

The molar teeth of a human, horse and dog. The first image to the left in a molar tooth of a horse.…