ALIMENTARY CANAL 



253 



and the appearance of gastric glands in the wall of the latter 

 cavity afford the only distinction between the two regions. The 



, ^ 3 Fig. 1.53.— Dissection of a 



male Dog -Pish (Scyl- 

 lium). The left side of 

 the body is cut away 

 to the median plane so 

 as to e.vpose tlie ab- 

 dominal and pericardial 

 cavities and the neural 

 canal in their whole 

 length. The alimentary 

 canal and the liver have 

 heen drawn downwards, 

 and the oral cavity, the 

 pharynx, part of the 

 intestine, and the cloaca 

 have been opened. The 

 cartilaginou.s paitsof the 

 skeleton are dotted, and 

 the calcified portions of 

 the vertebral centra are 

 black, aid.cav, Abdo- 

 minal cavity ; au, au- 

 ricle ; b.br, basi- bran- 

 chial ; b.hy, basi-hyal ; 

 cart, conns arteriosus ; 

 cd.a, caudal artery ; 

 cd. si, cardiac part of the 

 stomach ; cd.v, caudal 

 vein ; d, cloaca ; cv, 

 centrum ; cr, cranium ; 

 crb, cerebellum ; d.ao, 

 dorsal aorta ; dien, tha- 

 laraencephalon ; epid, 

 epididymis ; /ore, fonta- 

 nelle ; gid, oesophagus ; 

 h.a, haemal arch ; 

 i.br. a^ — i.br.a,^ internal 

 gill -clefts ; int, intes- 

 tine ; kd, kidney ; l.j, 

 lower jaw ; Z.fr, left lobe 

 of liver ; med.obl, me- 

 dulla oblongata ; ones, 

 mesentery ; n.a, neural 

 arch ; nxav, neural 

 canal ; ol/d, olfactory 

 lobes ; opt. I, optic lobes ; 

 pan, pancreas ; pcd.cav, 

 pericardial cavity ;^JC^.«, 

 pectoral arch ; -pjh, 

 phaiynx ; jjui, pineal 

 body ; p.n.d, ^'estigial 

 Mlillerian duct ; prs, 

 prosencephalon ; pty, 

 pituitary body ; pv.a, pelvic arch ; pyLst, pyloric portion of the stomach ; r, rostrum ; r.lr, right 

 lobe of liver ; rct.gl, rectal gland ; sp, spiracle ; sp.cd, spinal cord ; spil, spleen ; sp.s, sperm 

 sac ; sp.vl, spiral valve ; s.v, sinus venosus ; tng, tongue ; ts, testis ; ii.g.s, urino-genital sinus ; 

 w./, upper jaw ; ur, metanephric duct ; v, ventricle ; v.ao, ventral aorta ; v.def, vas deferens 

 or mesonephric duct ; vs.sem, vesicula seminalis. (From "Wiedersheim, after T. J. Parker.) 



