30 DARWINISM AND RACE PROGRESS. 



that acquired modifications are barely, if at all, in- 

 herited in the correct sense of the term." Thirteen 

 years later 1 he expresses himself in practically the 

 same terms. An untiring investigator, chiefly in the 

 facts of human heredity, he briefly sums up as above 

 one of his most important general conclusions. It 

 is all he has to say, it is all that his facts permit him 

 to say. 



In 1882, Weismann 2 questioned whether there is as 

 yet any proof that acquired characters are transmitted; 

 he writes : " The theoretical conception of variation 

 as a reaction of the organism to external influences has 

 also not yet been experimentally shown to be correct. 

 Our experiments are still too coarse, as compared 

 with the fine distinctions which separate one indi- 

 vidual from another, and the difficulty of obtaining 

 clear results is greatly increased by the circumstance 

 that a portion of the individual difference always 

 depends upon heredity, so that it is frequently not 

 only difficult, but absolutely impossible, to separate 

 those which are inherited from those which are 

 acquired." 



Since that time, Weismann, in a series of important 

 essays, 3 indicating a profound knowledge not only of 



1 " Natural Inheritance" (1889), p. 14. 



2 " Studies in the Theory of Descent," translated by Raphael 

 Meldola, p. 692. 



3 " Essays upon Heredity," translated by Poulton, Schon- 

 land and Shipley ; vol. i. published in 1889, vol. ii. in 1892. 



