208 



RODENTIA. 



it makes two or three loose turns : in all this course it is loose, only 

 connected to the lower and right edge of the mesentery : it has three 

 ligaments, as in the porcupine, which begin at the apex of the caecum, 

 and run through its whole length ; when two of them unite into one, 

 and then the two, now formed out of the three, run along the colon. 



This large gut becomes small almost at once, about 1| inch from 

 the termination of the ileum : this small part, which is about 1| inch in 

 diameter, is bent back upon the caecum, adhering to it by a thin 

 membrane about an inch broad, for nearly two thirds of the length of 

 the caecum, and becoming smaller and smaller. The colon then leaves 

 the caecum, comes a little higher, and is attached to the right edge of 

 the mesentery near the root where the duodenum is attached. It then 

 makes a double fold upon itself, whence it crosses the root of the 

 mesentery on the anterior surface to the left side, adhering pretty 

 closely to the mesentery. Then it becomes a loose intestine and passes 

 down, having a pretty broad mesocolon and mesorectum ; and, as it is 

 much longer than the distance between the root of the mesentery and 

 anus, it is by that means thrown into convolutions at the upper part, 

 but is straight below. It seems to be in this last part that the faeces 

 become divided. 



The length of the small intestines is seven times the length of the 

 body of the animal : the caecum is more than two-thirds that length : 

 the colon and rectum are four times the length of the body 1 . 



The liver is divided into four lobes besides the lobulus Spigelii : these 

 four are just like those of the squirrel or rat. The lobulus Spigelii is 

 wholly behind the mesogaster. The gall-bladder is a round cavity, 

 very thin, attached to the second lobe from the left side, and is attached 

 to the right half of that lobe upon the right side of the sulcus for the 

 ligamentum rotundum and falx ; this attachment is by a thin doubling 

 of peritoneum, about a quarter of an inch broad, so that if there were 

 any cyst-hepatic ducts here, I think we might see them. The cystic 

 duct passes along to the porta, is pretty long, wide, and straight, not 

 contorted, and is attached to the liver only by a thin membrane. At 

 the porta it is joined by the hepatic ducts, which are two or three in 

 number, and are very short. The ductus communis passes, as common, 

 to the gut upon the left of the vena porta and artery, some way ; it is 

 very superficial, as the ' capsule of Glisson ' is only peritoneum, and 



1 [Home, in abstracting the above description (Comp. Anat. i. p. 447), accidentally 

 omits to give the name of the animal, and makes it follow the intestinal anatomy of 

 the marmot. Hunter's expressions of doubt are omitted. " Perhaps this appear- 

 ance is owing to the contraction," is " This appearance is produced by the contrac- 

 tion." " It seems to be in this last part," is " In this last part the fa?ces are divided."] 



