TRANSLATOR'S PREFACE 



Every student of heredity is brought face to face with 

 the problem of some mechanism of inheritance. Pan- 

 genesis was Darwin's solution of this problem. But it 

 was not in the form in which Darwin left it that pan- 

 genesis became directly fruitful of results; and no one 

 felt the insufficiency of his hypothesis more keenly than 

 Darwin himself. Writing to Asa Gray in 1867 he said: 

 'The chapter on what I call Pangenesis will be called a 



mad dream but at the bottom of my own mind 



I think it contains a great truth." 1 And to J. D. Hooker, 

 in 1868, he wrote : "I feel sure if Pangenesis is now still 

 born it will, thank God, at some future time reappear, be- 

 gotten by some other father, and christened by some other 

 name/' 2 



Many men discerned the weak features of the hypoth- 

 esis, but to Hugo de Vries belongs the credit of having 

 detected the "great truth" it contained. He became its 

 "other father," and rechristened it with another name 

 a name more nearly like the original, no doubt, than 

 Darwin could have imagined. 



The pangenesis of Darwin was hardly susceptible of 

 experimental verification, except to the extent that a more 

 intimate acquaintance with the facts showed that the 

 assumption of a transportation of "gemmules" was super- 



iDarwin, C Life and Letters. 2: 256. New York, 1901. 

 2 Loc. cit. p. 261. 



