THE PASSING OF DARWINISM. 



49 



diverge in character as they become modified [i.e. by definite variation] 

 ... so as to be classifiable as ' families, genera and species, &c.' 



" The solution, as I believe, is that the modified offspring of all 

 dominant and increasing forms tend to become adapted [my italics] to 

 many and highly diversified places in the economy of Nature." * 



But this " tendency " requires stimulation. What happens is 

 that the descendants get dispersed into various conditions of life, so 

 that each varies again by self-adaptation in response to the direct 

 action of the environments ; consequently different varieties or species 

 arise, all, collectively, making a genus. 



This was a " problem " Darwin said he had previously overlooked, 

 but does not say when it occurred to him ; all he remarks is : "I 

 can remember the very spot in the road, when, to my joy, the solution 

 occurred to me ; and this was long after I had come to Down." f (1842.) 

 In what year was it ? I would suggest about 1864. 



The words " tend to become adapted," therefore, correspond to the 

 present-day expression " responds to the direct action of changed 

 conditions of life." " Adaptations " are due to the directivity of life. 

 He herein gives us his two alternatives, which are mutually exclusive. J 



It is remarkable that we read nothing more about " adaptation " 

 in the " Origin &c." 1st to 6th eds., nor in the " Variation &c." 

 The word does not occur in the index of either. " Adaptations " 

 are the result of this " tendency to respond " ; but Darwin unfortu- 

 nately seems not to have studied or experimented with wild plants^ 

 for had he done so he could not have written the following sentence : 

 " Even with modifications resulting from the definite action of the 

 conditions of life, § when all or nearly all the individuals which have 

 been similarly exposed are similarly affected we can rarely see the 

 precise relation between cause and effect." || My experiments have 

 taught me the exact reverse ; the most profound changes, internal 

 and external, are immediate and obvious at once, 



" My first note-book," Darwin says, " was opened in July 1837, 

 and without any theory I collected facts on a wholesale scale, more 

 especially with respect to domesticated productions. ... I soon per- 

 ceived that Selection was the keystone of man's success in making [?] 

 useful races of animals and plants. But how selection could be 

 applied to organisms living in a state of nature remained for some time 

 1 a mystery to me."** 



Variability and Natural Selection. — The following are Darwin's 

 words when defining his famous theory ; it may be called the locus 

 classicus of Natural Selection : " Can we doubt (remembering that 



* Life &c. p. 84. 

 t Op. cit. p. 82. 



% The theory of natural selection, we shall see, entirely excludes all " tendency 

 to adaptation " ; if adaptations arise they are by " accident." (See below.) 



§ Variation &c. ii. p. 271. 



II Op. cit. ii. p. 292. 



I would refer the reader to my books : The Origin of Plant Structures, 

 The Heredity of Acquired Characters in Plants, and papers in the Jour. Linn. Soc. 



** Life &c. i. p. 83. 



VOL. XLI. E 



