412 ORGANS OF DIGESTION. 



supply of pure water, received at long intervals in the arid 

 plains they inhabit. The second stomach is more appro- 

 priated to the retention of water than the large paunch, and 

 receives it directly from the mouth, unmixed with the food, 

 pouring over to the cells of the first stomach a quantity of 

 the fluid when its own are filled. The third stomach (130. 

 A. d.) 9 which is here of a lengthened form, is provided both 

 with longitudinal and transverse internal folds of its mucous 

 coat, and the fourth cavity (130. A. e.) is of an elongated 

 narrow form, curved suddenly towards its pyloric end (130. 

 A. /.) and puckered like a colon. The fourth stomach of 

 the ruminantia is the first developed, the largest, and alone 

 employed for digestion, during the earlier periods of exis- 

 tence and during lactation. The milk, in suckling, passes 

 down through the oesophagus to the closed valvular folds, 

 which check its entrance into the first or second stomach, 

 and convey it along the canal which they form, directly to 

 the third or foliated cavity. The third stomach not having 

 been yet distended with solid food so as to separate from 

 each other its numerous contiguous laminae, it merely forms 

 a tube through which the milk passes into the fourth sto- 

 mach; and thus the nutritious fluid of the parent is con- 

 veyed directly into the proper digestive stomach of the 

 suckling ruminant, without being accumulated or retarded 

 in any of the previous cavities. 



The intestinal canal of the ruminantia is of great length, 

 being sometimes more than thirty times the length of the 

 trunk of the body, as in the sheep, and the colon is always 

 long, convoluted, and of great width compared with the small 

 intestine. The long narrow small intestine has generally 

 thin membranous parietes, a villous internal surface, and a 

 short mesentery to suspend its numerous convolutions from 

 the vertebral column. The ccecum-coli is long, wide, and, 

 like the colon itself, has smooth internal parietes. The colon 

 is not here puckered and sacculated by longitudinal bands 

 as it is in many herbivorous quadrupeds, and forms nu- 

 merous long convolutions before it descends on the left side 

 to terminate in the rectum. The liver is more deeply divided 

 into lobes than in the cetacea, but less than in most car- 

 nivorous quadrupeds; many have a large and elongated 

 gall-bladder, while others, as the camels and deers, are des- 

 titute of this reservoir ; the gall-duct, whether from the liver 



