324 



ZOOLOGY 



SECT. 



Qd 



The stomach (Fig. 967, M, Fig. 9G8, St) is a cylindrical organ 

 but little wider than the a^sophagus, and with thick muscular walls. 

 At the ])oint where the small intestine joins the large intestine 

 or rectum, the latter is produced into a short nccam (Fig. 9G0, Ccr). 



The liver (Ir) is divided into right 

 and left lobes, and a gall-bladder 

 (Fig.9(37,6;,^.;Fig.9G8,^.A; Fig. 

 909, g.hl) lies at the lower margin 

 of the right lobe. The pancrenji {pii) 

 is situated in the loop between 

 the stomach and first part of the 

 small intestine or duodenum {dv^. 

 The stomach is attached to the 

 body-wall by a fold of peritoneum, 

 the mesogaster, the small intestine 

 by a fold termed the mcsenUry, 

 the rectum by a meso-rcctum. From 

 the dorsal surface of the liver to 

 the stomach extends a thin fold, 

 the ga&tro-hcipatic omentum ; and 

 this is continued backwards as the 

 dnodeno-hepatic omentum, connect- 

 ing the liver with the first portion 

 of the small intestine. 



Vascular System. — The heart 

 is enclosed, like that of the Frog, 

 in a thin transparent membrane, 

 the pericardium. It consists of a 

 simts venosics, right and left auricles, 

 and an incompletely divided ven- 

 tricle. The sinu-s venosiiH (Fig. 968, 

 ■s. v.), into which the large veins 

 open, is thin walled, and has a 

 smooth inaer surface. From it a 

 sinu-auricular aperture, guarded by 

 a two-lipped valve, leads to the 

 right auricle. The auricles have 

 their inner surfaces raised up into 

 a network of muscular ridges, the 

 musculi pcctinati. Both auricles 

 open into the cavity of the ven- 

 tricle, the aperture of communication, or auriculo-vcntricidar aper- 

 ture, being divided into two by the auricular septum, and guarded 

 by the auriculo-ventricular valve, consisting of two semilunar Haps. 

 The ventricle (Fig. 968, v. ; Fig. 969, vent.) has very thick spongy 

 walls and a small cavity, divided into two parts by an incomplete 

 muscular partition. From the part of the ventricular cavity to 



Fig. 9G7.— Lacerta agilis. General 

 view of the viscera in their luitural 

 relations. Bl. urinary bladder ; Ci. post- 

 caval vein ; ED, rectum ; GB. gall- 

 bladder ; H. heart ; Lif. Lif. the lungs ; 

 M, stomach ; MD, small intestine ; Oi:. 

 (esophagus ; Fn. pancreas ; Tr. trachea. 

 (From Wiedersheim's C'ovrpttrative 

 Anatoiivi.) 



