SCHfLTE, SKI WHALE. 449 



the lines of the postcava on the right and the ascending duodenum and angle of the colic arch 

 on the left of the primitive mesenteric root. As a result the descending duodenum, more than 

 half of the transverse, and a considerable area of the pancreas are free on the right of the post- 

 cava, while the ascending colon covers and is adherent to the vertical portion of the pancreas, 

 ventrally concealing it from view. On the other hand the duodenum is wholly excluded from 

 the lesser sac, the usual peritoneal surface on the left of its first portion, here ampulla, is occu- 

 pied by the horizontal portion of the pancreas, which from its high position and adherence to 

 the liver must be considered to have invaded the gastro-hepatic omentum near its primitively 

 free margin, following the line of the bile duct and portal vein ventrally, in the position occasion- 

 ally taken by the development, as a variant, of the left ventral pancreatic anlage. The peri- 

 toneal covering of this region is still further reduced by the obliteration of the foramen of Winslow 

 (vide infra p. 452). 



In its interior the duodenum is smooth save for the presence of finger-shaped and conical 

 villi. I did not lay it open in its full length, but only to the beginning of its transverse portion. 

 In this portion there were no valvulse conniventes and the only definite longitudinal ridge was 

 related to the intramural portion of the bile duct. This elevation began at the angle between 

 the ampulla and the second portion and continued through about half the length of the descend- 

 ing duodenum. At its distal extremity was a small punctate orifice. The several portions 

 of the duodenum had the following lengths irrespective of their curvature: ampulla 7 mm.; 

 descending 11 mm.; transverse 10 mm.; ascending 14 mm. 



Jejuno-ileum. The remainder of the small intestine forms a closely coiled mass which 

 occupies an oblique position in the abdomen, extending from the first compartment of the 

 stomach and the diaphragm on the left, caudad and dextrad to the interval between the extrem- 

 ity of the liver and the right kidney. The intestine is all but wholly confined to the preum- 

 bilical portion of the abdomen, only a few small coils project beyond the umbilicus into the 

 space between the kidneys. The mesentery has a short attachment to the right of the ascending 

 duodenum occupying the interval between it and the ascending limb of the colon loop. At the 

 cephalic margin of the transverse duodenum the colon becomes free and here the mesentery is 

 continuous with the mesocolon. As the ileo-colic junction is just caudad of the duodenum, the 

 extent of free mesocolon at this point is but small, yet to this degree the mesenterium com- 

 mune has been retained. The coils of the small intestine are closely packed and very numerous. 

 They may be described in Gadow's terms as plagiocoelous with a very considerable degree of tel- 

 ogyry. While perhaps the majority of the coils showed a tendency to form a double spiral, 

 in few did it much exceed a half turn and in none was a complete turn accomplished. On the 

 other hand some of the coils were quite irregular. On further analysis the mass of small coils 

 can be resolved into six major loops, each of which crosses the line of the mesentery transversely, 

 from right to left or vice versa and having done so turns caudad to be continuous with the suc- 

 ceeding loop, which returns to the opposite side reversing the general direction of its predecessor. 

 The first of these is directed from left to right, and its mass of coils of moderate size, is accumu- 

 lated at the cephalic extremity of the mesentery. The second loop reverses this general direc- 

 tion, and so on, the odd numbered loops being directed from left to right, the even from right 

 to left. The third and fifth are large, the intervening fourth is very short, while the sixth arch- 

 ing round the caudal extremity of the mesentery far exceeds any of the others in extent. At the 

 ileo-colic junction the terminal ileum passes cephalad and somewhat ventrad and to the right, 



