DEGLUTITION IN THE OX. 91 



thence returned to the mouth for further mastication. The 

 grass is crushed rapidly, and swallowed by a process quite 

 similar to that by which the horse swallows his food. After 

 remaining in the first and second stomachs until thoroughly 

 impregnated with fluid, the food, in the form of little balls 

 or pellets, is returned at intervals to the mouth to undergo 

 the slow process of mastication and insalivation, which is 

 termed chewing the cud, or rumination. The process of 

 rumination occupies much time. It has even been estimated 

 that a fourth part of the day is spent in this operation. It 

 appears that the saliva is not merely mingled with the food 

 during the first and second periods of mastication ; but that, 

 in the interval between feeding and rumination, the saliva is 

 constantly swallowed, by which the contents of the paunch 

 are prevented from becoming so dry as not to be readily 

 transmitted to the mouth. It is further affirmed that ex- 

 periments show that if the course of the saliva into the paunch 

 be prevented, no amount of water swallowed will suffice to 

 keep the alimentary mass in a state soft enough for regurgi- 

 tation. To enable the food at its first deglutition to get into 

 the first stomach or paunch, it is necessary that it should be 

 somewhat dry and bulky, otherwise it fails to separate the lips 

 of the groove or demi-canal by which an entrance is gained to 

 the first and second stomachs. In proof of this it has been 

 shown that food reduced artificially to a soft and pulpy condi- 

 tion, when swallowed for the first time, passes along the demi- 

 canal into the third stomach, while only a small portion of the 

 mass makes its way into the first and second stomachs. When 

 the food has been macerated in the fluids of the first two 

 stomachs, with the aid of the saliva continually swallowed after 

 the first deglutition of food has ceased, it is returned by an 

 inverted peristaltic action of the gullet to the mouth. The 

 pellets of food so returned are moulded in the demi-canal, the 



