CHAPTER II 



THE RELATIONS OF PLANT AND ANIMAL LIFE 



The foundations of animal life are laid in the plant, 

 and with the plant must begin a study of the funda- 

 mental facts of animal nutrition. The first step toward 

 supplying animals with food is taken w^hen the farmer 

 drops seed into the warm earth. As soon as the j'oung 

 rootlets from a germinating seed come in contact with 

 the soil and the first leaves reach the air, assimilative 

 growth begins. During the hours of sunlight matter 

 is constantly gathered in an invisible way, which, after 

 transformation into various compounds, is added to the 

 enlarging tissues of the plant. This continues, per- 

 haps for a season, until the stalk of grain has reached 

 its full height and has attained the ultimate object 

 of its existence in the production of seed, or it may 

 go on for centuries, so that where now is only the 

 acorn there will be the giant oak. The farmer car- 

 ries to the field a few pounds of seed and he returns 

 to his storehouses laden with tons of new material, 

 perhaps hay, perhaps grain. From somewhere, in some 

 way, the plant has gathered various substances, often 

 no less than ten thousand pounds per acre in a single 

 year, and has manufactured them into forms that are 

 useful to the husbandman. 



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