The Descent of Man and Selection in Relation to Sex Volume I Part 29

[520] Mr. R. MacLachlan, 'Transact. Ent. Soc.' vol. ii. part 6th, 3rd series, 1866, p. 459.

[521] H. W. Bates, 'The Naturalist on the Amazons,' vol. ii.

1863, p. 228. A. R. Wallace, in 'Transact. Linn. Soc.' vol. xxv.

1865, p. 10.

[522] On this whole subject see 'The Variation of Animals and Plants under Domestication,' vol. ii. 1868, chap. xxiii.

[523] A. R. Wallace, in 'The Journal of Travel,' vol. i. 1868, p. 88. 'Westminster Review,' July, 1857, p. 37. See also Messrs. Wallace and Bates in 'Proc. Ent. Soc.' Nov. 19th, 1866, p. x.x.xix.

[524] 'The Variation of Animals and Plants under Domestication,' vol. ii. chap. xii. p. 17.

[525] 'Transact. Linn. Soc.' vol. xxiii. 1862, p. 495.

[526] 'Proc. Ent. Soc.' Dec. 3rd, 1866, p. xlv.

[527] 'Transact. Linn. Soc.' vol. xxv. 1865, p. 1; also 'Transact. Ent. Soc.' vol. iv. (3rd series), 1867, p. 301.

[528] See an ingenious article ent.i.tled, "Difficulties of the Theory of Natural Selection," in the 'Month,' 1869. The writer strangely supposes that I attribute the variations in colour of the Lepidoptera, by which certain species belonging to distinct families have come to resemble others, to reversion to a common progenitor; but there is no more reason to attribute these variations to reversion than in the case of any ordinary variation.

[529] Wallace, "Notes on Eastern b.u.t.terflies," 'Transact. Ent.

Soc.' 1869, p. 287.

[530] Wallace, in 'Westminster Review,' July, 1867, p. 37; and in 'Journal of Travel and Nat. Hist.' vol. i. 1868, p. 88.

[531] See remarks by Messrs. Bates and Wallace, in 'Proc. Ent.

Soc.' Nov. 19, 1866, p. x.x.xix.

[532] See Mr. Wallace in 'Westminster Review,' July, 1867, p.

11 and 37. The male of no b.u.t.terfly, as Mr. Wallace informs me, is known to differ in colour, as a protection, from the female; and he asks me how I can explain this fact on the principle that one s.e.x alone has varied and has transmitted its variations exclusively to the same s.e.x, without the aid of selection to check the variations being inherited by the other s.e.x. No doubt if it could be shewn that the females of very many species had been rendered beautiful through protective mimickry, but that this has never occurred with the males, it would be a serious difficulty. But the number of cases as yet known hardly suffices for a fair judgment. We can see that the males, from having the power of flying more swiftly, and thus escaping danger, would not be so likely as the females to have had their colours modified for the sake of protection; but this would not in the least have interfered with their receiving protective colours through inheritance from the females. In the second place, it is probable that s.e.xual selection would actually tend to prevent a beautiful male from becoming obscure, for the less brilliant individuals would be less attractive to the females. Supposing that the beauty of the male of any species had been mainly acquired through s.e.xual selection, yet if this beauty likewise served as a protection, the acquisition would have been aided by natural selection. But it would be quite beyond our power to distinguish between the two processes of s.e.xual and ordinary selection. Hence it is not likely that we should be able to adduce cases of the males having been rendered brilliant exclusively through protective mimickry, though this is comparatively easy with the females, which have rarely or never been rendered beautiful, as far as we can judge, for the sake of s.e.xual attraction, although they have often received beauty through inheritance from their male parents.

[533] 'Proc. Entomolog. Soc.' Dec. 3rd, 1866, p. xlv., and March 4th, 1867, p. lx.x.x.

[534] See Mr. J. Jenner Weir's paper on insects and insectivorous birds, in 'Transact. Ent. Soc.' 1869, p. 21; also Mr. Butler's paper, ibid. p. 27.

END OF VOL. I.