My dear Sir

You end y^r letter of Sep. 9 by saying that it is a very dull one; indeed you make a very great mistake, for it abounds with interesting facts & thoughts.¹ Your account of the tameness of the birds which apparently have wandered from the interior, is very curious.

But I must begin on another subject: there has been a great & very vexatious, but unavoidable delay in the publication of your book. Prof. Huxley agrees with me that Mr Dallas is by far the best translator, but he is much overworked & had not quite finished the translation about a fortnight ago.² He has charge of the Museum at York & is now trying to get the situation of Assistant Sec. at the Geolog. Soc; & all the canvassing &c, & his removal, if he gets the place, will I fear cause more than a month’s delay in the completion of the translation; & this I very much regret.³

I am particularly glad to hear that you intend to repeat my experiments on illegitimate offspring, for no one’s observations can be trusted until repeated.⁴ You will find the work very troublesome, owing to the death of plants & accidents of all kinds. Some dimorphic plants will probably prove too sterile for you to raise offspring; & others too fertile for much sterility to be expected in their offspring. Primula is bad on account of the difficulty of deciding which seeds may be considered as good. I have earnestly wished that some one would repeat these experiments, but I feared that years w^d elapse before any one w^d take the trouble. I received y^r paper on Bignonia in Bot. Zeit. & it interested me much.⁵ I am convinced that if you can prove that a plant growing in a distant place under different conditions is more effective in fertilization than one growing close by, you will make a great step in the essence of sexual reproduction.⁶

Prof. Asa Gray & D^r Hooker have been staying here & oddly enough, they knew nothing of y^r paper on Martha; tho’ the former was aware of the curious movements of the stamens, but so little understood the structure of the plant that he thought it was probably a dimorphic species. Accordingly I shewed them your drawings & gave them a little lecture & they were perfectly charmed with your account.⁷ Hildebrand has repeated his exp. on potatoes & so have I, but this summer with no result.⁸ I am particularly obliged to you for y^r observations on the stridulation of the 2 sexes of Lamellicorns: I begin to fear that I am completely in error, owing to that common cause viz mistaking at first individual variability for sexual difference.⁹

I go on working at sexual selection, & tho’ never idle I am able to do so little work each day that I make very slow progress.

I will sow the seed of the Chinese Cabbage & look out for the very curious montrosity.¹⁰ I knew from Azara about the young of the tapir being striped, & about young deer being spotted; I have often reflected on this subject, & know not what to conclude about the loss of the stripes & spots.¹¹

From the Geograph. Distribution of the striped & unstriped species of Equus there seems to be something very mysterious about the loss of stripes; & I cannot persuade myself that the common ass has lost its stripes owing to being rendered more conspicuous from having stripes & thus exposed to danger.

Believe me my dear Sir | yours very sincerely | Charles Darwin