1902 - 3 .] Abdominal Viscera o/Cercocebus fuliginosus, etc. 537 
vicinity of the hepatic flexure of the colon. That is to say, the 
dorsal and ventral layers of the omentum separate at this point. 
The ventral layer has its line of attachment crossing the duodenum 
obliquely to gain the greater curvature of the stomach, along which 
it is continued as far as the notch separating the saccular fundus 
from the tubular body. Then, as stated in an early part of this 
paper, it forsakes the curvature and crosses the caudal surface of 
the fundus obliquely, to ultimately reach the spleen. The dorsal 
layer of the omentum soon becomes confounded with the meso- 
colon, as will be explained later. 
There is nothing remarkable about the gastro-hepatic omentum. 
The duodenum has no trace of mesentery, its fixation being very 
complete. The mesentery has a narrow root on a level with the 
termination of the duodenum. When it is traced to the termina- 
tion of the ileum, it is found to become attached along the lesser 
curvature of the ascending colon as far as the hepatic flexure, 
|where it is continuous with the mesocolon. Except for a small 
triangular fold of peritoneum which joins its lesser curvature to 
the ileum, the caecum is entirely surrounded by peritoneum. The 
ascending colon has no mesocolon ; its dorsal surface being nearly 
entirely devoid of peritoneal investment, as it is in man. The 
arrangement of the peritoneum with regard to this part of the 
colon will perhaps be best understood from an examination of the 
diagram given in fig. 6. All the other parts of the colon have a 
very well developed mesocolon ; this being especially the case in 
connection with those parts which have been earlier referred to as 
A and B. It is easier to trace the parietal line of attachment of the 
mesocolon from the point where it is continuous with the meso- 
rectum. If this is done, the line is found to be at first in the 
mesial plane. Then, passing cephalwards, it deviates to the left, 
and so comes to cross the ventral surface of the left kidney. Then 
it turns over towards the right, and a union of the mesocolon and 
the dorsal layer of the great omentum begins. This union is very 
slight on the left side of the abdomen ; but it becomes gradually 
greater as the two structures are followed to the right. At the 
hepatic flexure the two abruptly separate; the mesocolon to 
become continuous with the mesentery which is attached to 
the lesser curvature of the ascending colon; the dorsal layer 
PROC. ROY. SOC. EDIN. — YOL. XXIV. 35 
