SCHULTE, SEI WHALE. 457 



men is closed and the peritoneum of the greater sac passes uninterruptedly over the cava from 

 the portal vein, so that the gastro-duodenal ligament receives an extension to the right and 

 dorsad, and one can follow the anterior layer of the gastro-hepatic omentum continuously from 

 portal vein over postcava to adrenal and abdominal wall, passing in a horizontal direction from 

 left to right. From above downwards the reflection is from portal vein, caudate lobe and cava 

 to the ampulla duodeni. Thus the free edge of the gastro-hepatic omentum is lost and the site 

 of the primitive foramen is marked only by a shallow preduodenal recess. 



The remainder of the anterior layer of the gastro-hepatic omentum follows the usual line 

 of reflection from the transverse fissure and that of the ductus venosus; it is peculiar only in 

 its angular extension upon the proximal portion of the umbilical fissure, occasioned by the 

 extensive adherence of the pancreas to the liver in this region. This has been accomplished 

 by the extension of the pancreas into the gastro-hepatic omentum, with the consequence of 

 first separating its layers, secondarily of effecting adhesions in the reduplicature of the ental 

 layer interposed between liver and pancreas, and ultimately entailing obliteration of much 

 of the retrogastric space. As a consequence of this process only the ectal layer of the omentum 

 is retained in its transverse segment, and this is reduced to a mere reflection of peritoneum from 

 the liver to the lesser curvature of the fourth and third gastric compartments, which are 

 closely attached to the undersurface of the gland. Only beside the papillary process does 

 the vertical segment retain its two layered condition, and only here has the gastro-hepatic 

 omentum an appreciable length, spreading out from its attachment upon the liver to the lesser 

 curvature of the second stomach. Above the papillary process the omentum becomes reduced 

 again to a single layer the consequence of the obliteration in large part of the Spigelian 

 recess and here again it is a mere reflection from liver to first stomach. 



Arrived at the lesser curvature the ectal layer of the gastro-hepatic omentum passes over 

 the ventral surface of the stomach to the greater curvature of the second, third and fourth com- 

 partments and thence descends as the ectal layer of the great omentum. Turning at its margin 

 it ascends to the margin of the pancreas that intervenes between its colic and gastro-hepatic 

 surfaces and is there reflected caudad upon the colon, whence it may be traced to the right leaf 

 of the mesentery. Upon the first compartment of the stomach it passes to the fundus and there 

 is reflected over the spleen as the gastro-splenic omentum, for here again the lesser sac is lack- 

 ing and the region of the hilus is not in peritoneal contact with the stomach but is adherent 

 to it. Beyond the spleen the line of this reflection ascends on the one hand to the angle between 

 the first and second compartments, and on the other skirts the colic area of the fundus to the 

 transverse division of the pancreas, at both of these points joining the lines of omental reflection 

 that have already been described. 



The lesser sac, it has already been pointed out, is peculiar in the loss of the foramen of 

 Winslow, the obliteration of the splenic, and the reduction of the Spigelian recesses. These 

 changes are undoubtedly secondary and associated with the collocation of viscera in the pre- 

 umbilical region. The lesser sac as a result is reduced to a relatively simple retrogastric space 

 and the cavity of the great omentum. Their mutual boundary is given by the attachment 

 of the great omentum, which has already been traced in the description of its ectal layer. It 

 is shown in Plate LIT, Fig. 1. 



The great omentum was crumpled into a mass which lay at the greater curvature of the 

 stomach, to the left of the falciform ligament and above the coils of the small intestine. It 



