288 Colour and the Struggle for Life 



appeared in the following year, and after reading it Darwin 

 wrote as follows, Nov. 20, 1862: "...In my opinion it is one 

 of the most remarkable and admirable papers I ever read in my 



life I am rejoiced that I passed over the whole subject in the 



Origin, for I should have made a precious mess of it. You have 



most clearly stated and solved a wonderful problem Your paper is 



too good to be largely appreciated by the mob of naturalists without 

 souls ; but, rely on it, that it will have lasting value, and I cordially 

 congratulate you on your first great work. You will find, I should 

 think, that Wallace will fully appreciate it 1 ." Four days later, 

 Nov. 24, Darwin wrote to Hooker on the same subject: "I have 

 now finished his paper. . . ; it seems to me admirable. To my mind 

 the act of segregation of varieties into species was never so plainly 

 brought forward, and there are heaps of capital miscellaneous 

 observations 2 ." 



Darwin was here referring to the tendency of similar varieties 

 of the same species to pair together, and on Nov. 25 he wrote to 

 Bates asking for fuller information on this subject 3 . If Bates's 

 opinion were well founded, sexual selection would bear a most im- 

 portant part in the establishment of such species 4 . It must be 

 admitted, however, that the evidence is as yet quite insufficient to 

 establish this conclusion. It is interesting to observe how Darwin at 

 once fixed on the part of Bates's memoir which seemed to bear upon 

 sexual selection. A review of Bates's theory of Mimicry was con- 

 tributed by Darwin to the Natural History Revieiv 5 and an account 

 of it is to be found in the Origin^ and in The Descent of Man 7 . 



Darwin continually writes of the value of hypothesis as the 

 inspiration of inquiry. We find an example in his letter to Bates, 

 Nov. 22, 1860: "I have an old belief that a good observer really 

 means a good theorist, and I fully expect to find your observations 

 most valuable 8 ." Darwin's letter refers to many problems upon 

 which Bates had theorised and observed, but as regards Mimicry itself 

 the hypothesis was thought out after the return of the letter from the 

 Amazons, when he no longer had the opportunity of testing it by the 

 observation of living Nature. It is by no means improbable that, 

 had he been able to apply this test, Bates would have recognised 

 that his division of butterfly resemblances into two classes, one due 



1 Life and Letters, n. pp. 391393. 

 * More Letters, i. p. 214. 



3 More Letters, i. p. 215. See also parts of Darwin's letter to Bates in Life uinl 

 Letters, n. p. 3<J2. 



4 See Poulton, Essays on Evolution, 1908, pp. 65, 85 88. 



5 New Ser. Vol. in. 1863, p. 219. " Ed. 1872, pp. 375378. 

 7 Ed. 1874, pp. 323325. 8 More Letters, i. p. 176. 



