436 A CENTUEY OF SCIENCE 



pies. The Eugenics Record Office has secured many of 

 the essential data. 



With the destruction of the world's best germ plasm 

 at a rate never equalled before, the outlook for the future 

 race would be appalling were it not for the hope that with 

 the advent of a righteous peace will come a realization of 

 the necessity of applying these new biological discoveries 

 to improving the races of men. That the discoveries 

 have been made too late in the world's history to be of 

 such use to humanity must not be thought possible. 



Evolution. 



Previous to the publication of Darwin's " Origin of 

 Species" in 1859, American zoologists were generally 

 inclined toward special creation, in spite of the evidences 

 for evolution which had been presented by Erasmus Dar- 

 win, Buffon, Lamarck, and Geoffroy St. Hilaire. This 

 attitude of mind continued for some years after the pub- 

 lication of the natural selection theory of Darwin and 

 Wallace. This was in part due to the powerful influence 

 of Louis Agassiz and others who bitterly opposed the 

 Darwinian theory. The influence of Asa Gray in gaining 

 a general acceptance for this theory is explained in the 

 following chapter. 



A modified Lamarckian doctrine was widely accepted 

 in the last quarter of the century, due largely to the 

 influence of Cope, Hyatt and Packard. The inheritance 

 of * ' acquired characters ' ' demanded by this theory seems 

 incompatible with the discoveries of recent times, so that 

 " today the theory has few followers amongst trained 

 investigators, but it still has a popular vogue that is wide- 

 spread and vociferous." 12 



The origin of new varieties and species by accidental 

 and fortuitous modifications (mutations) of the germ- 

 plasm is now the most widely accepted theory of evolu- 

 tion. 



Some of the most important discoveries regarding the 

 origin of new forms have been recently made by Morgan 

 and his pupils. From a stock of the common fruit fly 

 (Drosophila ampelophila) more than 125 new types have 

 arisen within six years. Each of these types breeds true. 

 ''Each has arisen independently and suddenly. Every 



