WCP1768

[1]

Godalming

June 10th. 1889

My dear Mr. Geddes¹

I have to thank you for your very kind, appreciative and flattering review of my book in the "Scottish Leader", and especially for your having been so considerate as to resist the temptation to give a severe criticism of the parts in which I oppose your views.

I should be very glad, should occasion come, to have a friendly discussion with you, though I think some person more skilled in practical botany would be better able to [2] meet your special cases.

I may say, generally, that no amount of such examples as you refer to seem to me to have any real bearing on your views ^contention, because, even if the production of thorns & spines does occur by means of an "ebbing vitality" — at the spot where the thorn arises, that by no [means] implies a general ebbing vitality in the plant. If, in most cases, thorns are modified branches — as I admit, — they can only become thorns by losing ^{some of} their vigour of vegetative growth — but [3] it seems to me quite certain that spines, are often modified hairs, & in this case the vigour of their vegetative growth has been increased. In each case nat. select. has seized upon the variations which, at the time when they were required, offered the best means of securing the required protection.

Unless you can give a reasonable explanation of why "ebbing vitality" — which must be a constant phenomenon everywhere — produces such different results in continents & in oceanic islands, I must hold your contention on this [4] point to be entirely unproved.

Believe me | Yours very sincerely | Alfred R. Wallace [signature]

P.S. Though I may think you very wrong in imputing such definite results to your principle, I none the less am delighted to see you at work at it, & only hope for your own sake — that you will keep your application of it to the minimising of nat. select. within strict limits of probability or of possibility.

A.R.W.

At midsummer I leave Godalming. My new address will be Corfe View Parkstone Dorset.