THE VITAL PRINCIPLE — THE BLOOD. 19 



their victims at once into their digestive cavity. 

 Granivorous birds, also, swallow their food 

 whole, but the carnivorous tear the flush into 

 strips or morsels, and swallow it. In the par- 

 rot, however, something like mastication is 

 observable, the mobility of the mandibles of its 

 beak enabling it thus to treat the food upon 

 whicli it naturally subsists. The toucan, too, 

 crushes and squeezes with its beak the unfor- 

 tunate bird which it has seized before swallowing 

 it, and this may be called a sort of mastication. 

 Among mammalia, neither the dog or wolf, nor 

 the lion or tiger, can be said to masticaU 

 food ; they rend the flesh into portions, which 

 are bolted at once. The whales and grampuses, 

 also, swallow their prey at once. On the other 

 hand, in such animals as the horse, the ox, the 

 sheep, the deer, and others, implication is care- 

 fully performed, and their teeth are ex; 

 fitted for a grinding action, the salivary glandf, 

 too, t being large. Man, also, masticat< 

 ought to masticate his food ; for this p: 

 during which the food becomes of a du< 

 perature, and is mixed with a certain portion of 

 saliva, is requisite for its easy digestion. 



It is to the digestive process, as carried on 

 in the human species, that we shall here con- 

 fine our attention. h\ all other animals the 

 process is essentially the same, and involves the 

 agency of a chemical solvent. The food crushed 

 by the teeth, and mixed with saliva, is transfer- 

 red to the stomach, where it is maintained at the 

 temperature of 100° of Fahrenheit, and kept in 



