Recent Developments in Heredity and Evolution 21 



having simply been discovered and pedigreed, without the 

 labor of continuous selection year after year, and without 

 the old inconstancy in the result. To reduce labor, to 

 multiply cultural forms, and to obtain constant results 

 in plant breeding are results of very large importance to 

 the material side of human welfare. Pedigree culture has 

 not only multiplied available forms, but it has begun to 

 be used most effectively in combating drought and disease, 

 the most dangerous enemies of cultivated plants. Drought- 

 resistant races are being developed from pedigreed stock, 

 and immunity to different diseases has been found to be 

 a transmissible character. When it is remembered that 

 drought-resistance not only insures crops over areas now 

 cultivated, but also secures an enormous extension of area 

 that can be cultivated; and that the annual losses from 

 plant diseases represent an enormous financial total; it 

 will be appreciated that the study of heredity and evolution, 

 with purely scientific purpose, incidentally has been enor- 

 mously profitable on the practical side. 



I have sketched a background that will permit those who 

 follow to put their work in its setting without much loss 

 of time. The interest lies chiefly in the foreground that 

 they will develop, for it will represent the work of today. 



