OF PERIPATUS CAPENSIS. 883 



what folded and fairly thick walls, and lies freely in the central 

 division of the body-cavity without any mesenteric support. Its 

 walls are formed of five layers, viz. from without inwards. 



(1) A peritoneal investment. 



(2) A layer of longitudinal fibres. 



(3) A layer of circular fibres, amongst which are numerous 

 nuclei. 



(4) A connective-tissue layer supporting (5) a layer of fairly 

 columnar hyaline epithelium, bounded on its inner aspect by 

 a cuticle continued from that of the pharynx. In front it passes 

 insensibly into the pharynx, and beyond the region where the 

 dorsal walls of the pharynx have clearly commenced, the ventral 

 walls still retain the characters of the cesophageal walls. The 

 oesophagus is vertically oval in front, but more nearly circular 

 behind. Characteristic of the oesophagus is the junction of the 

 two sympathetic nerves on its dorsal wall (fig. 16). These 

 nerves cannot be traced far beyond their point of junction. 



The Stomach. The next section of the alimentary tract is 

 the stomach or rnesenteron (fig. 6). It is by far the largest 

 part of the alimentary tract, commencing at about the second 

 pair of legs and extending nearly to the hind end of the body. 

 It tapers both in front and behind, and is narrowest in the 

 middle, and is marked off sharply both from the oesophagus in 

 front and the rectum behind, and is distinguished from both of 

 these by its somewhat pinker hue. In the retracted condition 

 of the animal it is, as pointed out by Moseley, folded in a single 

 short dorsal loop, at about the junction of its first with its second 

 third, and also, according to my observations, at its junction 

 with the rectum ; but in the extended condition it is nearly 

 straight, though usually the posterior fold at the junction of the 

 rectum is not completely removed. Its walls are always marked 

 by plications which, as both Moseley and Grube have stated, do 

 not in any way correspond with the segmentation of the body. 

 In its interior I have frequently found the chitinous remains of 

 the skins of insects, so that we are not justified in considering 

 that the diet is purely vegetable. It lies free, and is, like the 

 remainder of the alimentary tract, without a mesentery. The 

 structure of the walls of the stomach has not hitherto been very 

 satisfactorily described. 



