98 ANIMAL FUNCTIONS. 



foregoing pages, and we shall now proceed to treat of 

 the animal functions, reserving for future consideration the 

 action of the human muscles, which can be most properly 

 noticed when we come to speak of Physical Education. 



SOURCES OP NUTRITION. 



The nutrition which nature has provided for the vari- 

 ous tribes of animals, is derived, entirely, from two 

 sources, namely, from the animal and vegetable king- 

 doms. But as the carnivorous tribes derive their food 

 from those which are herbivorous, the nourishment of 

 all is ultimately derived from the earth itself. 



Vegetable food. The economy of nature, is no where 

 more wonderfully manifest than in the adaptation of 

 animals to the consumption of every kind of nutrition, 

 there being hardly any organized substance which does 

 not furnish food for some living creature. The succu- 

 lent parts of vegetables are not only the chief source of 

 nourishment of the greater proportion of the larger ani- 

 mals, but also serve the same purpose to myriads of 

 insects. Many tribes of birds likewise, live on vegeta- 

 bles, but insects become the food of the larger number, 

 while not a few are strictly carnivorous. But while 

 these substances are the common food of the most 

 numerous races, even the hardest parts of vegetables, 

 and the most poisonous plants serve the same purpose to 

 certain other tribes. The larvae of various insects live 

 by eating their way through the diseased portions of 

 timber logs ; while the Nettle, the Deadly Night-shade, 

 the Henbane, and other acrid and poisonous plants, 

 afford wholesome food to several species. Some live 

 on fruits and seeds, and others on the juices which they 

 pump from succulent plants. 



Animal food. But while a vast number of tribes 

 thus subsist on the fruits of the ground, these in their 

 turn become the prey of at least as great a number of 



Whence do animals derive their nutrition 7 What is said of the ex- 

 tent to which vegetables serve as the food of animals ? 



