BOTANIC GARDENS COULTER. 467 



exactly to the variable conditions in which plants must be grown. 

 It is a curious fact that we have been blind so long to the teaching of 

 nature that conditions for plants are not the same everywhere. We 

 have always realized that the natural vegetation of this country is 

 not a monotonous covering. Every change in vegetation indicates 

 a special set of conditions for plant growth, and yet we have been 

 trying to grow the same races of plants everywhere. The result has 

 been that we have gotten maximum returns from some areas, mini- 

 mum returns from others, and medium returns from the rest. Our 

 total result has been an average. By multiplying races of plants to 

 fit conditions more closely, our total result will not be an average, 

 but a maximum everywhere. This one suggestion of science will 

 double our production. 



One of the most destructive enemies of our crops is drought. On 

 the average our production is cut in half by this enemy. Scientific 

 investigation has shown that it is possible to develop drought - 

 resistant races of all our useful plants. This means the possibility, 

 not only of insuring our crops against drought where they are now 

 cultivated, but also of increasing enormously the area of cultivation, 

 by adding the so-called arid regions of perpetual drought. 



Another destructive enemy of our valuable crops is disease. The 

 Government has expended millions of dollars in the study of plant 

 diseases, in the hope of reducing the loss. The scientific work of 

 recent years has shown that it is possible to breed disease-resistant 

 races. Plants, like human beings, differ in their susceptibility to 

 diseases. Some are immune, and others are susceptible. This means 

 that we can cultivate immune races and let the susceptibles perish. 

 We cannot handle human diseases in this way. Before what we 

 speak of as the wonderful advance of medicine, we were uncon- 

 sciously practising selection of the human race for immunity. The 

 susceptibles disappeared and the immunes survived. Now medicine 

 has been so successful that it saves the susceptibles and keeps them 

 mixed with the immunes, so that our human problem is more diffi- 

 cult than it used to be. But we have no such sentiment about plants, 

 and we can cultivate immunity and eliminate susceptibility. 



I am told by those who are trained in collecting such statistics 

 that if these suggestions of scientific research can be generally ap- 

 plied, our food production will overtake our population. It is in. 

 such ways that the results of science find application. This is not 

 merely a local service, but a national service, and in such a time as 

 this it is a patriotic service. 



May I recall your attention to the work of the National Research 

 Council in connection with your opportunity. This council has been 

 appointed by the National Academy of Sciences at the request of 

 President Wilson. Its purpose is to bring into cooperation all of our 



