528 Proceedings of Royal Society of Edinburgh. [sess. 
of the ascending colon, to which the mesocolon is attached, is 
mesial in position. There are several sacculations on this part of 
the large intestine, but none of them is well marked. 
The hepatic flexure is fairly abrupt, the intestine turning first 
towards the mesial plane, and then ventralwards. The transverse 
colon is a little longer, but somewhat narrower, than the ascending 
colon, its length being 100 mm. as against 80 mm. for the 
initial part of the colon. It is in the form of a U-shaped tube : 
or perhaps it would be better to say that it is Y-shaped, with the 
angle of the Y rounded off and forming the most ventral part of 
this portion of the intestine. The greater curvature being directed 
ventralwards and inclining a little towards the pelvis, the most pro- 
nounced part of the bend is visible, caudal to the liver, as soon as the 
abdomen is opened (PI. III. fig. 6, TC). The concavity of the trans- 
verse colon is in contact with the lesser curvature of the stomach. 
The sacculations on this length of the intestine are only very faint. 
The splenic flexure occupies a position a little more caudal than 
that of the hepatic flexure, and it is not so abrupt as the previous 
bend of the colon. It is lodged in the angle formed by the spleen 
and the stomach. The descending colon is curved in a manner 
similar to that of the ascending colon. It is narrower than the 
part immediately preceding it, especially in its more caudal part ; 
and its sacculations are well marked. In the formation of the 
sigmoid flexure the colon alters its direction in the following 
manner. It first runs ventralwards and to the right. Having 
arrived just to the right of the mesial plane, it turns cephalwards. 
and towards the dorsum of the body. Then there is a sudden 
swerve to the left, leading to the last part of the flexure, which 
runs caudalwards to the entrance to the pelvis, dorsal to the first. 
On the ascending colon there are three, not very distinct, longi- 
tudinal bands. One of these is placed along the greater curvature, 
and, therefore, lies to the right, i.e., it is lateral in position. The 
second is ventral, and the third is dorsal. Hone of these bands 
can be followed on to the caecum ; but they can all be traced for 
variable distances on to the other parts of the colon. Of the three, 
the lateral band passes for the greatest distance. It is continued 
along the transverse and descending colon, and only fails at the 
last turn of the sigmoid flexure. The ventral band can be 
