448 ANNALS NEW YORK ACADEMY OF SCIENCES 



having a certain relation to the parent, it can estabUsh a race hke itself and 

 even supplant the parent form, if it is only as well fitted for the battle of life 

 as is the progenitor.^ 



If Darwin had known these facts he would not have written, or he 

 would have greatly amended, the following passage: 



"He who believes that some ancient form was transformed suddenly through 

 an internal force or tendency into, for instance, one furnished with wings, will be 

 almost compelled to assume, in opposition to all analogy, that many individuals 

 varied simultaneously. It can not be denied that such abrupt and great changes of 

 structure are widely different from those which most species apparently have under- 

 gone. He will further be compelled to believe that many structures beautifully 

 adapted to all the other parts of the same creature and to the surrounding conditions, 

 have been suddenly produced; and of such complex and wonderful co-adaptations, 

 he will not be able to assign a shadow of an explanation. He will be forced to admit 

 that these great and sudden transformations have left no trace of their action on the 

 embryo. To admit all this is, as it seems to me, to enter into the realms of miracle, 

 and to leave those of science." ^ 



Of course Mr. Darwin was not entirely oblivious to the fact that every 

 important advance in knowledge must have the appearance, at first, of a 

 move into a region of mystery and uncertainty. The lapse of time and the 

 growth of familiarity with it are necessary to the reclamation of a terra 

 incognita. 



Before leaving this branch of my subject, I desire to call your attention 

 to the very interesting fact that Mr. Darwin himself once conducted a long 

 series of experiments which, it can hardly be doubted, resulted in the pro- 

 duction of mutants and that he just missed the discovery of principles which 

 are now the basis of scientific pedigree cultures and are occupying the atten- 

 tion of investigators of the problems of variation and heredity. In a letter to 

 J. H. Gilbert, dated February 16, 1876, Mr. Darwin writes: 



"Now, for the last ten years I have been experimenting in crossing and self- 

 fertilizing plants; and one indirect result has sm-prised me much, namely, that by 

 taking pains to cultivate plants in pots under glass during several successive genera- 

 tions, under nearly similar conditions, and by self-fertilizing them in each generation, 

 the colour of the flowers often changes, and, what is very remarkable, they became 

 in some of the most variable species, such as Mimulus, Carnation, &c., quite constant, 

 like those of a wild species. This fact and several others have led me to the suspicion 

 that the cause of variation must be in different substances absorbed from the soQ 

 by these plants when their powers of absorption are not interfered with by other 

 plants with which they grow mingled in a state of nature." ^ 



1 See Lock's "Variation, Heredity and Evolution," 1906, p. 205. 



2 " Origin of Species," 6th ed., p. 204. See also, ibid., p. 202. 

 8 " Life and Letters," 1886, Vol. Ill, p. 343. 



