402 PLANT PECULIARITIES 



and they employ other millions in the production of cotton 

 plants and cotton cloth for our clothing. 



The farmer who raises plants has an interest in knowing 

 what kind of soil and climate, how much water, air, and 

 light each kind of plant needs to yield him the best results. 

 To this end he has to know something about the habits of 

 plants in general, and about their enemies and their dis- 

 eases. He has learned by experience that some plants 

 grow better when planted in hills ; others in drills, and 

 still others sown broadcast. He is still trying to find the 

 best kind of plant food for each plant, and the method of 

 cultivation which best enables plants to get their full 

 supply of food and moisture, and he is still fighting weeds 

 which deprive the useful plants of their share of food, 

 water, and light. Yet he is conscious, if he stops to con- 

 sider, that he cannot make a plant grow. His part is to 

 create good vital conditions. 



We are interested in the work of men who are trying 

 by cross-pollination, grafting, and selection to reduce the 

 undesirable parts of plants and to increase their capacity 

 for food, storage or whatever we find desirable. Luther 

 Burbank has made many experiments along these lines, 

 especially in increasing the number of fruits on trees and 

 in reducing the size of the seeds in berries. 



278. Scientific Interest. — In addition to practical in- 

 terests, that is, besides the supreme importance of plants 

 to man and his dependence upon them, there is another 

 interest, — that of the scientist in plants as organisms. 

 The scientist studies how plants are like animals ; how 

 they differ from them ; how each is dependent upon the 

 other for waste products ; how plants depend upon animals 

 for the pollination of their flowers and the scattering of 

 their seeds, and how the plants make use of the wind and 

 water for the same purposes. 



