THE IMPROVEMENT OF PLANTS 581 



to consider their value as forage crops for animal food, and here a much 

 greater latitude for selection is possible. A very large number of our 

 native plants should be tested and the most promising improved for 

 forage purposes. 



In the development of leguminous crops we have a valuable field 

 of research. Of the many hundreds of legumes, we now cultivate only 

 about a dozen species, such as beans, peas, clover, alfalfa, crimson clover, 

 cowpeas, soy beans and the like, representing a natural adaptation to 

 as many localities. None of the species ordinarily cultivated in the 

 northern United States are natives of this great section. Yet an ex- 

 amination of the botanies shows that some 150 different species of 

 legumes are natives of this section. Would it not seem absurd to as- 

 sume that our present cultivated species represent the best types for 

 this section, when the most promising of those that the great Master 

 Breeder gave us have not been thoroughly improved and tested? 

 Among the wild native species of Desmodium, Vicia, Lespedeza and 

 other legumes, we have a number of promising sorts. We have tested 

 many of these species in comparison with our ordinary cultivated crops 

 and discarded them, but our tests have been of the wild, unimproved, 

 against the improved types. We might as reasonably put gloves on a 

 wild pygmy of Africa and test him on the mat with a trained modern 

 athlete. 



Doubtless the mere mentioning of the improvement of native plants 

 suggests to the minds of each one of you some wild plant that you have 

 observed and thought to possess valuable qualities. If our sources of 

 nitrogen supply are to be exhausted soon, we must cultivate more legu- 

 minous crops that can gather their own nitrogen and improve the soil 

 in this respect while furnishing crops. We should have leguminous 

 tuber crops to take the place of potatoes, beets and turnips. Nature 

 has given us such wild legumes as the groundnut {Apios tuberosa) and 

 the Pomme de Prairie {Psoralea esculenta), which already have edible 

 tubers and which could doubtless be developed into very valuable culti- 

 vated plants by a few years of breeding. 



Dr. J. Eussell Smith,^ of the University of Pennsylvania, has em- 

 phasized the importance of breeding tree crops, and here we have an 

 inexhaustible field of experimentation. We should breed chestnuts, 

 walnuts, hickories, oaks, beeches, hazelnuts, and the like, in order to 

 improve them for the use of man and for growth as stock food. Many 

 hundreds of thousands of acres of rough, hilly land unadapted for cul- 

 tivation would be suited for the growth of such crops. 



The possibilities of breeding tree crops are well illustrated by the 

 excessive increase in vigor, rapidity of growth and size of fruit ob- 

 tained by Burbank in a hybrid between the English walnut (Juglans 



''Smith, J. Russell, "The Breeding and Use of Tree Crops," American 

 Breeders' Association, Vol. I., p. 86. 



