No. 507] DARWIN'S "ORIGIN OF SPECIES" 



171 



exclusive means of modification (p. 421). 



3. The following explicit statement makes it very clear 

 that Darwin did not regard natural selection in the light 

 of an originating cause : 



Some have imagined that natural selection induces variability, whereas 

 it implies only the preservation of such variations as arise and are bene- 

 ficial to the being under its conditions of life (p. 63). 



It would appear that Huxley, in 1860, thought that 

 natural selection was being urged as an originating cause. 

 He says: 



It is not absolutely proven that a group of animals having all the 

 characters exhibited by a species in Nature has ever been originated by 

 natural selection, whether artificial or natural. 



He also thought that Darwin embarrassed himself by 

 the use of the aphorism, natura non facit saltum; that 

 nature does make a jump now and then, and that a 

 recognition of the fact is of no small importance in dis- 

 posing of many minor objections to the doctrine of trans- 

 mutation. In 1861, in a letter to Hooker, he says : 



The great desideratum for the species question at present seems to me 

 to be the determination of the law of variation. . . . Why does not 

 somebody go to work experimentally, and get at the law of variation 

 for some one species of plant? 



In 1885 he was reading the "Origin of Species" and 

 finding it one of the hardest books to understand that he 

 knew. In 1888 he says in a letter to Hooker : 



Darwin has left the causes of variation and the question whether it 

 is limited or directed by external conditions perfectly open. 



Writing to Bateson, February 20, 1894 (!), he says: 



I see you are inclined to advocate the possibility of considerable 

 "saltus" on the part of Dame Nature in her variations. I always 

 took the same view, much to Mr. Darwin's dissrnst, and we used often 

 to debate it. 



In the light afforded by these comments of Huxley, and 

 after a careful rereading of the "Origin of Species/' I 

 am inclined to the belief that in the brilliant work of 

 Hugo DeVries we may have a key to a real understanding 

 °f the difficulties in question. 



