266 THE SALAMANDER 



the capillary loops follow the same wavy outline. The network is 

 much richer at the anterior end of the gut. 



7. The Rectum. 



The rectum (rect.), like that of the Frog, is an expanded flask- 

 shaped structure arising quite suddenly from the posterior end of 

 the intestine. It is much thinner walled than the rest of the gut. 

 Crofts (1925) has described 'a small lateral "cul-de-sac" lying to the 

 left side' of the rectum and containing lymphoid tissue, which she 

 considers to be the homologue of the rectal gland of Elasmobranchs. 

 It is supplied by the haemorrhoidal artery. It is often difficult to 

 determine the exact location of this gland by direct observation, but 

 is more easily seen when the rectum is full than when it is empty, as 

 then it shows up against the dark faecal matter. The internal surface of 

 the rectum is also traversed by longitudinal ridges, set fairly close 

 together and thicker than in the intestine, but not so wide as in the 

 stomach. It differs from the latter also in that the vascular network 

 extends into the ridges. The rectum and urino-genital organs dis- 

 charge their contents into a common cloacal chamber, but since 

 the cloaca has a closer functional association with the latter organs it 

 is described together with them (see p. 286). 



THE GLANDS ASSOCIATED WITH THE 

 ALIMENTARY TRACT 



The glands associated with the gut, in addition to those already 

 mentioned, are the liver^ the pancreas, and the spleen. The association 

 of the last-named with the stomach is topographical only, since it has 

 neither functional nor developmental connexion with the gut. 



I. The Liver. 



The liver (liv.) is large, and only very slightly lobed. It lies ventral 

 and to the right of the stomach, and, in the fresh condition, is dark 

 red in colour. The lejt side of the gland is prolonged posteriorly into 

 a thin leaf-like lobe. The backward extension of the right side is not 

 so well defined nor so thin, but from this side of the liver there is a 

 pronounced dorsal extension which encircles the post-caval vein, and 

 which may hence be termed the post-caval lobe. It extends dorsally 

 right to the point where the post-caval separates from the post- 

 cardinal veins. The liver is completely suspended by mesenteries 



