268 THE SALAMANDER 



THE MESENTERIES 



The mesenteries of the Salamander exhibit many interesting 

 features. They have been investigated by Klaatsch (i 893), Mathes 

 (1896), and Brachet (1896). These authors are at some variance — 

 in fact each seeks to correct his immediate predecessor, but the causes 

 of their dissension lie in the mode of origin of the mesenteries 

 rather than in their final relationships, so that it is unnecessary to 

 enter into the long and rather involved discussion here. The following 

 description therefore applies simply to the relations as they may be 

 observed by the dissection of the adult. 



1. The Dorsal Mesentery and its Derivatives (see also Pis. XX, 

 XXI, and XXIII). 



The dorsal mesentery (l.d.) attaches the gut to the dorsal body-wall. 

 It is not quite a continuous sheet of membrane but is interrupted at 

 the pyloric end of the stomach by a large circular hole, the posterior 

 rim of which is bounded by the pancreas. Anteriorly the mesentery 

 extends as far as the base of the lungs, i.e. approximately to the level 

 of the anterior end of the ventricle of the heart. 



The gonads are suspended by a pair of lateral diverticula from the 

 dorsal mesentery which form the mesovaria (l.ms.) in the female and 

 the mesorchia (l.mch.) in the male. 



The kidneys are not suspended by a definite mesentery but lie fairly 

 close to the body-wall ; there is, however, a mesentery attaching the 

 oviduct in the female, and the Wolffian duct in the male, to the outer 

 edges of the kidneys. 



The spleen is suspended from the left side of the stomach also by 

 a reduplication of the dorsal mesentery. This fold is continued from 

 both ends of the spleen as a 'tuck' in the mesentery. The anterior 

 prolongation reaches to the stomach-wall and is the plica gastro- 

 lienalis (Klaatsch), while the posterior extension is much longer and 

 reaches to the rectum, and is the plica recto-Uenalis (Klaatsch). It is 

 important to notice that this latter fold does not follow the convolu- 

 tions of the intestine, but stretches straight across the comparatively 

 short distance between the posterior end of the spleen and the anterior 

 end of the rectum, so that the whole of the convoluted part of the 

 mesentery lies ventral to it. 



2. The Ligamentum Hepato-entericum (l.h-e.). 



Between the ventral side of the stomach and the dorsal surface of 

 the liver there is a mesentery which carries the factors of the anterior 



