DIGESTIVE SYSTEM. 41 



it first merits the special name of a Compound stomach, from its being 

 divided into four different cavities. The Sheep will serve best as a 

 type of this structure, which, however, does not differ essentially in 

 the Ox, Goat, &c. The first stomach is called the paunch (rumen 

 s. ingluvics) ; it is the largest, situated most to the left side, and 

 usually projects below into a pair of blind appendages ; its inner sur- 

 face presents very prominent, conical, and hard papillae. The sec- 

 ond stomach, the honey-comb (reticulum s. ollula) lies more in front, 

 above and to the right of the paunch, is small and round, and has a 

 similar hard epithelium upon the mucous membrane, the projecting 

 folds of which unite to form hexagonal cells, which are beset with 

 small pointed warts. The third, likewise small, placed more supe- 

 riorly, arid to the right behind the liver, is called the psalterium or 

 many plies (omasus), the internal lining membrane of which forms 

 numerous deep folds, lying iipon each other like the leaves of a book, 

 and beset with small hard tubercles. To this succeeds the fourth stom- 

 ach, named rennet (abomasus), of larger size than the two prece- 

 ding, elongated, and terminating in the duodenum, and provided with 

 a velvety mucous membrane disposed in several longitudinal folds. 

 The oesophagus enters to the right far into the paunch, but in such 

 a manner, that what is called the cesophageal groove passes at the 

 same time through the honey-comb into the third stomach, or 

 many-plies. This groove consists of two longitudinal ridges of 

 muscle and mucous membrane, which commence from the paunch 

 as thin folds, and form in the reticulum two thicker lips, having be- 

 tween them a groove, which, by the approximation of its edges, can 

 be converted into a canal. The food first reaches the paunch by 

 the usual route, and is then regurgitated bit by bit from it back 

 again through the reticulum into the gullet, and so into the mouth, 

 where having been rechewed, it is swallowed and conveyed within 

 the closed groove, between the folds of the psalterium, whence it 

 advances into the fourth stomach. Fluids are conveyed directly 

 through the cesophageal groove into the rennet. In the Camel and 

 Llama the construction is essentially the same, but with some modi- 

 fications. The paunch, and also the reticulum, have here a great 

 number of peculiar shaped cells ; the psalterium is very small, and 

 nearly free from folds, and the rennet intestiniform. The cells are 

 indicated externally as bladder-like elevations, arranged in groups. 

 In the Cetacea (and what is remarkable, in the carnivorous kinds) 

 compound stomachs also occur, the structure of which is best known 

 in the Dolphins. Four stomachs are found ; the first, lying to the 



