WCP4230

[1]

Parkstone, Dorset.

Sept^r. 11th. 1892

My dear Cockerell¹

I must first congratulate you on the accession of a son to your family, I hope he is quite well, & also Mrs Cockerell.²

I have specially to thank you for your excellent _letter ^article in this week’s "Nature," — defending me from Merriman’s wild attack. You have said exactly what I should have said had I thought it worthwhile to enter into a controversy with him; but it comes much better from you. I enclose you a list from "Allen",³ of the Mammals of Florida⁴ almost all the general & many of the species being Canadian [2] and not one of them from Cuba, and but few of the species in Yucatan.

Again 46 of the land-birds of Florida extend to Canada! I am especially glad you pointed out that the terms "sub-tropical" Florida & "frigid" Canada, were descriptive merely to point the illustration for popular readers.

Again, in such a personal criticism he might have noticed that I took my subregions mainly from Spencer Baird;⁵ and Allen says that his Eastern & Western Provinces, are "quite distinct from each other in their general features as well as in many special characteristics." It is not so certain after all that Merriman’s new division is any better than this. [3] On Merriman’s principle you might prove that Japan is more Malayan than Palaeartic, while the S.W. corner of Ireland sh^d be cut off from the rest, as "South European"!

Your paper on the development of species of moths and their larvae is very ingenious, and something of the kind has probably happened, but unless it can be worked out for particular allied species and proved by some kind of direct and impressive evidence, I hardly think it worth while devoting too much time to such purely speculative explanations. There are probably a score of ways in which the species of moths [4] have arisen, and even the case of the same genus one set of species may have arisen through one set of causes, another group of species through another.

A letter from me telling you about your paper on varieties of slugs being returned from the "Annals" must have crossed with your last.

You letter on Indexing Zool. Literature is suggestive and interesting, but would not the result be awfully cumbersome ^{and unequal} if everybody indexed their own works fully? Some would give almost the whole work in index-slips, others only the merest heads. Editorship would still be wanted, & it would be difficult. Still some modification of the plan might be hit upon that w^d. be very useful.

Yours very faithfully | Alfred R. Wallace [signature]