SCIENTIFIC INTEREST 
377 
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 consider, 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 
Figure 349. —Tropical Vegetation. 
Note how different the plants are from ours. 
undesirable parts of plants and to increase their capacity for 
food, storage, or whatever we find desirable. Experiment 
stations maintained by the United States Department of 
Agriculture and by individual states are making many ex¬ 
periments in this field, especially in increasing the number of 
fruits on trees and in reducing the size of the seeds in berries. 
316. Scientific Interest. — In addition to practical in¬ 
terests, that is, besides the supreme importance of plants 
