46o POPULAR SCIENCE MONTHLY. 



shall thus be able not only to tell what are the factors of phylogenetic 

 change, but also the rate of such change. We shall get possession of 

 the laws of evolution so that we can not only reconstruct the past, but 

 also predict the future development of a race. 



The importance of knowing the methods of evolution is partly 

 theoretical, like the importance of astronomical investigation, and 

 partly practical. For, on the one hand, a rapid and thoroughgoing 

 improvement of the human race can probably be effected only by 

 understand and applying these methods; and on the other hand, the 

 improvement of live-stock and of food plants must depend on a knowl- 

 edge of the laws of phylogenesis. How appalling is our ignorance, for 

 example, concerning the effect of a mixing of races as contrasted with 

 pure breeding; a matter of infinite importance in a country like ours 

 containing numerous races and subspecies of men. How little do we 

 know of the direct effect of climate on 'blood' ; a matter of concern in a 

 land with such diversified geography. In our fast-filling earth all 

 problems will some day be secondary to that of raising more grain or 

 beef to the acre; then at least the biologic-evolutionary problems will 

 be recognized as paramount. It is for us to anticipate in part the 

 future demands on biology. The State Experiment Stations of our 

 day are doing something in this direction, but for the most part in too 

 narrow a fashion. For the future, broad, far-reaching experiments in 

 evolution are required, with a quantitative study of causes and results. 



