Pre-Darwinian Hints of Natural Selection 17 



finds in Prichard's work a recognition of the operation of Natural 

 Selection. "After inquiring how it is that 'these varieties are de- 

 veloped and preserved in connexion with particular climates and 

 differences of local situation/ he gives the following very significant 

 answer : ' One cause which tends to maintain this relation is obvious. 

 Individuals and families, and even whole colonies, perish and dis- 

 appear in climates for which they are, by peculiarity of constitution, 

 not adapted. Of this fact proofs have been already mentioned.'" Mr 

 Francis Darwin and Prof. A. C. Seward discuss Prichard's " anticipa- 

 tions " in More Letters of Charles Darwin, Vol. I. p. 43, and come to 

 the conclusion that the evolutionary passages are entirely neutralised 

 by others of an opposite trend. There is the same difficulty with 

 Buffbn. 



Hints of the idea of Natural Selection have been detected else- 

 where. James Watt 1 , for instance, has been reported as one of the 

 anticipators (1851). But we need not prolong the inquiry further, 

 since Darwin did not know of any anticipations until after he had 

 published the immortal work of 1859, and since none of those who 

 got hold of the idea made any use of it. What Darwin did was to 

 follow the clue which Malthus gave him, to realise, first by genius and 

 afterwards by patience, how the complex and subtle struggle for 

 existence works out a natural selection of those organisms which 

 vary in the direction of fitter adaptation to the conditions of their 

 life. So much success attended his application of the Selection- 

 formula that for a time he regarded Natural Selection as almost the 

 sole factor in evolution, variations being pre-supposed ; gradually, 

 however, he came to recognise that there was some validity in the 

 factors which had been emphasized by Lamarck and by Button, and in 

 his well-known summing up in the sixth edition of the Origin he says 

 of the transformation of species: "This has been effected chiefly 

 through the natural selection of numerous successive, slight, favour- 

 able variations ; aided in an important manner by the inherited 

 effects of the use and disuse of parts ; and in an unimportant manner, 

 that is, in relation to adaptive structures, whether past or present, 

 by the direct action of external conditions, and by variations which 

 seem to us in our ignorance to arise spontaneously." 



To sum up : the idea of organic evolution, older than Aristotle, 

 slowly developed from the stage of suggestion to the stage of verifi-^A 

 cation, and the first convincing verification was Darwin's ; from being 

 an a priori anticipation it has become an interpretation of nature, 

 and Darwin is still the chief interpreter ; from being a modal interpre- 

 tation it has advanced to the rank of a causal theory, the most 

 convincing part of which men will never cease to call Darwinism. 



1 See Prof. Patrick Geddes's article "Variation and Selection," Encyclopaedia 

 Britannica (9th edit.) 1888. 



D. 2 



