80 EVERS'S COMPARATIVE ANATOMY. 



the third stomach, termed mam/plies, or omasum, aid from thence 

 into the fourth stomach called abo?nasum, or rennet bag-. Of these 

 cavities, the first is the largest, and the third the smallest. The three 

 first are lined with cuticle, and the fourth, which is next in capacity 

 to the paunch is lined with a soft mucous coat folded in the longitu- 

 dinal direction. This is the proper digestive stomach, and is analo- 

 gous to the digestive sac of carnivorous and higher quadrupeds. 

 The fourth stomach of the ruminantia is the first developed ; in the 

 earlier periods of life it is the largest, and the only one employed in 

 digestion. The mechanism by which milk is transmitted directly 

 into the fourth stomach during the period of suckling is this, the 

 G3Sophagus enters just where the three first cavities approach each 

 other, here it can open directly into the first or second stomach, but 

 instead of terminating there, it is continued in the form of a groove 

 with prominent lips, which admit of being drawn together so as to 

 form a complete canal, which then constitutes a direct continuation 

 of the oesophagus into the third stomach, but this cavity not having 

 been distended with solid food in the young animal, it merely forms 

 a tube through which the milk passes into the fourth stomach. In 

 the adult animal the same mechanism continues, but here the third 

 cavity having been already distended, receives the bolus after 

 rumination. 



In the ruminants without horns, as the dromedary, the camel, 

 and the lama, a somewhat different but not less beautiful mechanism 

 prevails, fitting them to live in the sandy deserts and arid plains 

 they inhabit. In these animals the paunch consists of two com- 

 partments, the first of which receives the un masticated food from 

 which it is returned to the mouth, moistened by the fluid of the 

 second or cellular compartment. After the cud has been chewed, 

 the food passes along the upper part of the second cavity into the 

 third, and from that to the fourth. When the camel drinks, the 

 water passes directly into the second cavity, and when this is full 

 it flows into the neighbouring cellular compartment of the paunch. 

 In the bullock, the three first cavities are lined with cuticle ; in the 

 camel it lines only the two first, and terminates just within the ori- 

 fice of the third, the surface of which has a faint appearance of 

 honey-comb structure. From the comparative view which has 

 been taken of the stomach of the bullock and camel, it appears, that 

 in the bullock there are three cavities formed for the preparation of 

 of the food, and one for its digestion. In the camel, the two com- 

 partments of the first cavity answer the purposes of the two first 

 stomachs of the bullock ; the second is employed as a reservoir for 

 water only ; the third is so small and simple in its structure, that it 

 is not easy to ascertain its particular office, whilst the fourth is that 

 in which the process of digestion is accomplished. 



As a general rule, it may be stated that the intestinal canal is 

 long, large, and sacculated in the herbivorous tribes, and short, 

 straight, and without sacculi, in the carnivora. Some remarkable 

 exceptions, however, present themselves, for instance in makies, 



