Dear Mr Darwin,

I must write one line to say with how much pleasure I have read your book.¹ Effie says it is all egotism because you have put my name in it.² But this is all spite on her part. I think the thing that strikes me in it—apart from the combined width and caution which characterize all your generalizations—is the laborious & long continued application of artificial experiment to processes of life and growth, which have generally been the subject of mere observation. What an endless vista of work it opens up!

I am so glad you give Spencer and writers of that kind a rub, for covering up ignorance by big words: and stating as an universal truth that of which we only know very partial instances.³

The two sets of facts which strike me most are the effects of a cross with a variety or individual which has grown under different conditions: and the occasional production amongst self fertilized or constantly intercrossed plants of exceptional vigour & qualities. The first set of facts seem to establish your great generalization. The second surely point to some important feature in living beings and their reproduction, of which we are as yet profoundly ignorant.

Lathyrus odoratus & Pisum sativum were very interesting to me.— Curious that they should so long retain an elaborate structure which is quite useless.⁴ But would they do so if exposed to the struggle of uncultivated Nature instead of being protected in gardens?

I am very glad to see that your son Frank has found a meaning for that puzzling spur in Phaseolus.⁵

Believe me | Sincerely yours | T H Farrer