144 THE VITAL FUNCTIONS. 



and the sheep, tlicre are two preparatory stomachs for re- 

 taining the food previous to rumination, a third for receiving 

 it after it lias undergone this process, and a fourth for effect- 

 ing its digestion. Ruminants without horns, as tiic Camel, 

 Dromedar}", and Lama, have only one preparatory stomach 

 before rumination, answering the purpose of the two first sto- 

 machs of the bullock; a second, which I shall presently no- 

 tice, and which takes no share in digestion, being employed 

 merely as a reservoir of water; a third, exceedingly small, 

 and of which the office has not been ascertained; and a fourth, 

 which both receives and dij2;csts the food after rumination. 

 Those herbivorous animals which do not ruminate, as the 

 horse and ass, have only one stomach; but the upper portion 

 of it is lined with cuticle, and appears to perform some pre- 

 paratory office, which renders the food more easily digesti- 

 ble by the lower portion of the same cavity.* 



The remarkable provision above alluded to in the Camel, 

 an animal which nature has evidently intended as the inha- 

 bitant of the steril and arid regions of the East, is that of 

 reservoirs of water, which, when once filled, retain their 

 contents for a very long time, and may minister not only to 

 the wants of the animal that possesses it, but, also, to those 

 of man. The second stomach of the Camel has a separate 

 compartment, to which is attached a series of cellular ap- 

 pendages; (exhibited, on a small scale, in Fig. 315:) in these 

 the water is retained by strong muscular bands, which close 

 the orifices of the cells, while the other portions of the sto- 

 mach are performing their usual functions. By the relaxa- 

 tion of these muscles, the water is gradually allowed to mix 

 with the contents of the stomach, and thus the Camel is ena- 

 bled to sujDport long marches across the desert, without re- 

 ceiving any fresh supply. The Arabs, who traverse those 

 extensive plains, accompanied by these useful animals, are, 

 it is said, sometimes obliged, when faint, and in danger of 

 perishing from thirst, to kill one of their camels, for the sake 



* Home, rhil. Trans. 8vo. 1806, p. 370. 



