STEUCTUKE OF COMPOUND STOMACHS. 795 



the second (c). The process of rumination, therefore, would seem to be 

 effected in the following manner : The herbage when first swallowed 

 in an unmasticated condition passes into the capacious paunch (d), 

 where it accumulates, and undergoes, no doubt, a kind of preliminary 

 maceration. When the Ruminant has done grazing, and is at leisure, 

 the food is again regurgitated into the mouth, to undergo more careful 

 and complete mastication : for this purpose, a part of it is admitted into 

 the reticulum (c), and there formed into a smooth and lubricated bolus, 

 which, being expelled into the oesophagus, is immediately seized by the 

 spiral muscles surrounding that canal and forced forwards into the 

 mouth. After undergoing a thorough trituration, the aliment is once 

 more swallowed, and it then enters into the third stomach (e), passing 

 along the muscular fold that leads from the oesophagus into that com- 

 partment. Here it is spread out over the extensive surface formed by 

 the laminated walls of the psalter ium, and is prepared for admission 

 into the last cavity (/), which, as has bee<n said, is the true digestive 

 stomach. 



(2309.) While the young Ruminant continues to be nourished by 

 its mother's milk, the three first cavities are undeveloped and compara- 

 tively very small; so that the milk passes on immediately into the 

 fourth stomach, to be at once appropriated as aliment. 



(2310.) In the Camel, the Dromedary, and the Llama, the walls of 

 the reticulum and of a portion of the paunch are excavated into deep 

 cells or reservoirs bounded by muscular fasciculi, wherein water may 

 be retained in considerable abundance, unmixed with the contents of the 

 stomach : it is in consequence of this arrangement that these animals 

 are able to subsist for many days without needing a fresh supply of 

 water even during long journeys in a tropical climate. 



(2311.) In the CETACEA the stomach consists of several bags that 

 communicate with each other. These bags vary from five to seven in 

 number; but in the present state of our knowledge concerning the 

 physiology of digestion it is difficult to divine what is the purpose of 

 such an arrangement, more especially as rumination is here out of the 

 question. The first stomach of the Whale, however, is no longer merely 

 a reservoir*, as the food undergoes a considerable change in it. The 

 flesh of its prey is entirely separated from the bones, which proves that 

 the secretion of this cavity has a solvent power. This was found to be 

 the case in the Bottle -nose Porpoise and in the large Bottle-nose Whale, 

 in both of which several handfuls of bones were contained in the first 

 cavity, without the smallest remains of the fish to which they had 

 belonged. In others the earth had been dissolved, so that only the soft 

 parts remained ; and, indeed, it is only partially- digested materials that 

 can be conveyed into the second and third cavities, the orifices being 

 too small to permit bones to pass. 



* Sir E. Home, Lectures on Comparative Anatomy, vol. i. p. 225. 



