SHAPE AND STRUCTURE OF ALIMENTARY VISCERA OF PORPOISE. 325 



nent rugae, and presented a miniature copy of the interior of the second stomach 

 chamber. Its capacity was about equal to that of the third compartment of the 

 stomach. The opening of the bile-duct was situated on a papilla {Papilla voteri) on 

 the dorsal wall of the duodenum, about half an inch (12 mms.) from the termination. 

 This termination was not marked by any valvular constriction, but was merely indicated 

 by a sudden reduction in calibre to the shape and proportions of the intestinal tube. 



From such a distinct and precise disposition of this portion of the canal there can be 

 no reasonable doubt that, so far as this animal is concerned, the duodenum should not be 

 regarded as a section of the intestine, but rather as a separate and special chamber 

 within which the liquid or peptonised food, having left the stomach, is subjected to the 

 action of the biliary and pancreatic secretions. It was a contention of the late Professor 

 Goodsir that the duodenum of man ought to be considered as a separate segment of the 

 bowel, on account of its attachments, structure, and functions. On these points, so far as 

 the porpoise is concerned, this view is quite clearly supported. 



Microscopically, the mucous membrane was remarkable for its negative as well as for 

 its positive characters. Villi were entirely wanting from its surface, and there were no 

 trace of Brunner's glands. 



The rugae already mentioned formed longitudinal ridges of muscularis mucosae 

 covered by the lining mucous membrane, which consisted of tubules similar to those 

 found in the adjoining intestine. 



The surface epithelium was, for the most part, denuded, but on some remaining 

 patches the cells were short and cubical. Each gland was comparatively straight, the 

 duct being lined by short columnar epithelium, while the deeper part of the gland 

 presented a considerable number of chalice cells. 



The intestine, which commenced at the end of the duodenum, extended to the anal 

 aperture as a tube of uniform appearance and supported by a single mesentery. In 

 calibre it appeared to be also fairly uniform, and although some parts were more firmly 

 contracted than others, there was no outward evidence of division into large and small 

 bowel. In its general appearance it resembled small bowel, and its least contracted 

 parts were not larger than the diameter of an average digit. No diverticulum or 

 appendix occurred anywhere. It measured rather more than fifty feet in length — i.e., 

 nearly twelve times the length of the animal. 



When we consider that the length of the human intestine is only from four to five 

 times as long as the individual, we are probably justified in associating the unusual 

 length of the intestine of the porpoise with the provision of an extended absorbing 

 surface in compensation for the absence of villi from its lining mucous membrane. 

 Transverse sections made at intervals along the entire length of the tube revealed the 

 presence of eight or nine longitudinal and projecting folds which occupied the greater 

 part of the lumen. These left very little free lumen, and in those places where the bowel 

 was firmly contracted, the cut face appeared almost solid by reason of the longitudinal 

 projections. In the first half or thereby of the bowel, these projections were fairly 



