4 26 



ANATOMY OF VERTEBRATES. 



321 



terminates at the base of the sacculate caecum, n\ the slender ter- 

 mination, <7, simulates a vermiform appendage: the colon begins 

 by a pair of large sacculi, r, but quickly contracts to the calibre 



shown at .9. Two oval 

 patches are here, as usual, 

 situated on either side of 

 the ileo-ca3cal valve. In 

 the LeporidcR they are 

 lodged in a .special pouch, 

 fig. 322, f: the vascular 

 mucous membrane of the 

 caecum, in these herbivo- 

 rous rodents, is augmented 

 by being produced into a 

 broad fold, disposed spi- 

 rally to near the slender 

 termination of the caecum, 

 d, b, which is glandular, 

 like the vermiform ap- 

 pendage in Man. Three longitudinal bands extend upon the 

 colon ; but two of these become blended together as that gut con- 



322 



Ci-ecum of the Arvicola amphibius. cxxu'. 



of the Hare. cxxu'. 



tracts, and the sacculi project from one side only, in which the 

 faecal contents begin to be moulded into the pellet-shaped excre- 

 ment. After the colon has completed its first long fold, returning 

 to near its commencement, the sacculi disappear. 



Besides the analogy already noted between the orifices of the 

 cascum and those of the stomach, that of the different diameters of 

 the entering and out-going tubes may be observed. Comparative 

 anatomy concurs with results of undesigned experiments, as in 

 cases where artificial openings have been established in the 



