FEEDING METHODS. 375 



when the ingredients are actually present they 

 must be in a form adapted to the animal's inter- 

 nal economy. Nature has not only ordained 

 the composition of the food, but its form. It 

 was once thought that animals had the power 

 of transforming materials from their simple 

 elemental form to a more complex state; of 

 preparing food for their own supply by modi- 

 fying it to suit their needs. But this view is 

 no longer commonly accepted. It is the part of 

 plants to convert the mineral matter of the soil 

 and air into the form needed by animal bodies, 

 and animals can only make use of it when so 

 converted. Hence it would follow that the 

 composition of animals and plants is nearly the 

 same so far as component elements go. And 

 this is quite true. The food of plants consists 

 mainly of water (oxygen and hydrogen), car- 

 bonic acid (carbon and oxygen), and ammonia 

 (hydrogen and nitrogen). These, as we have 

 seen, are the principal elements of animal 

 bodies. Not only is this so, but plants also 

 have incombustible elements in their compo- 

 sition, and these are similar to those found in 

 animal bodies. Hence it follows that nature 

 has prepared in plants just the complex food 

 that such animals as the ruminants to which 

 class the ox belongs demand. Our task is not 

 a hard one in general, then. Follow nature; 

 feed the stock as nearly as possible as they fed 



