8 PHYSIOLOGY AT THE FARM. 



the salivary glands. After this first reduction, the mass is 

 transmitted through the gullet into the stomach, to undergo a 

 further process of reduction. In animals having a single sto- 

 mach, like the horse, the pig, and the dog, the food is subjected 

 at once to the peculiar influence of the secretion termed the 

 gastric juice. There is nothing like mechanical trituration in 

 the stomachs of mammals. The action of the gastric juice is 

 closely allied to that of a mere chemical fluid, and the move- 

 ments to which the digesting mass is subjected have solely the 

 effect of bringing its several parts more completely within the 

 range of the influence of that fluid, and of transmitting the 

 portions already sufficiently operated on towards the outlet of 

 the stomach, and finally onwards to the upper part of the in- 

 testines. In ruminating animals like the ox and sheep, it is 

 the fourth of the four stomachs, termed the " rennet," which 

 corresponds to the one stomach of other mammals that in 

 which ventricular digestion is finally completed. In these 

 animals the food unless, being already in a pulpy state, it is fit 

 for the third and fourth stomachs passes from the mouth partly 

 into the first stomach, called the paunch, partly, yet not in the 

 same large proportion, into the second stomach, called the 

 honeycomb, and after being well moistened it is thrown up 

 from both into the mouth for further mastication and insali- 

 vation ; the mass next descends into the third stomach, termed 

 the manyplies, whence, after the requisite changes have been 

 accomplished, it is sent into the fourth or stomach proper, in 

 which the changes made upon it are effected by the agency of 

 a gastric juice, as in the stomachs of other mammals. Of the 

 long tract of the bowels, the duodenum, or uppermost part of 

 the small intestines, and the caecum, or uppermost part of the 

 great intestines, are almost exclusively the seats of important 

 changes on the alimentary mass. In the duodenum, the bile 

 or secretion of the liver, and the pancreatic juice or secretion 



