SHAPE AND STRUCTURE OF ALIMENTARY VISCERA OF PORPOISE. 317 



behind the lesser sac, with its head in the concavity of the duodenum, was found be- 

 tween the duodenum and the liver projecting to the left side, so as to be related to the 

 first and second chambers of the stomach within the folds of the lesser omentum. The 

 alteration in the peritoneal relations is best realised by supposing the pancreas to have 

 moved to the right and forwards (ventrally), and then upwards (anteriorly) between 

 the upper border of the duodenum and the liver, thereby separating the layers of the 

 gastro-hepatic omentum, and pressing its posterior or dorsal layer into contact with the 

 peritoneum covering the dorsal wall of the abdomen, until these two opposite walls of 

 the lesser sac have fused together. That there has been an alteration of this kind is 

 shown by the fact that the bile-duct has no free course, but from the under surface of 

 the liver enters the head of the pancreas and remains in it, until it pierces the wall of 

 the duodenum, and by the further fact that there is a reflection of peritoneum from the 

 under surface of the liver to the back of the head of the pancreas, completely occluding 

 any communication between the sac which lies on the dorsal aspect of the stomach and 

 the general or great peritoneal cavity. Furthermore, that part of the liver bounded by 

 the obliterated ductus venosus and the inferior vena cava (Lobulus spigelii), was 

 situated on the dorsal aspect of the liver, and was entirely devoid of peritoneal covering. 

 On the other hand, the Lobulus caudatus, situated on the dorsal aspect of the hilum of 

 the liver, was associated with a blind digital process of peritoneum. 



Between the layers forming the ventral part of the omentum, there was a curious 

 arrangement of lymphoid tissue. There wss a large number of bloodvessels in the 

 peritoneal membrane, and these vessels passed through small nodules of lymphoid 

 tissue, so that they produced the appearance of a bunch of grapes on a stalk, and the 

 arrangement closely resembled the condition present in the human spleen when the 

 vessels are isolated from the spleen tissue. A similar condition was not found in the 

 other parts of the peritoneum. 



Stomach. — As is well known, the stomach of this animal has been the subject of 

 much debate. Observers have agreed that it presented four compartments, but they 

 have differed as to the homologies and the sequence of these chambers, and, therefore, 

 their special interest in the present instance is due to the fact of their having been fixed 

 in a normal position so that they show their natural shapes, and consequently their 

 homologies can readily be understood. 



The different chambers composing the complex stomach had the following positions 

 and relations : — 1. The first and second chambers lay side by side, the first being 

 situated on the dorsal aspect of the other compartments, and somewhat to the right side 

 of the second compartment. The first compartment received the oesophagus at its 

 anterior end, and formed a somewhat conical bag, not unlike a cardiac ventricle, measur- 

 ing about five and a half inches (14 cms.) in the antero-posterior or long diameter, 

 and three and a half inches (9 cms.) in the dorso-ventral direction. The axis of the 

 chamber was a direct continuation of that of the oesophagus. It had two borders and 

 two surfaces. The one border was dorsal in position, straight in character, and carried, 



