Dear Sir

I have read the whole of your Book with great interest.² It contains very many views new to me & highly ingenious, & some new facts. I read it, however, to avoid fatigue in an uncritical spirit: Nevertheless shades of doubt crossed my mind often. You impress me with having so ardent a love of truth, that I believe you will prefer hearing a few unfavourable remarks rather than more praise.—

(p. 73 Sprengel & not Lubbock ought to be referred to about the mark “saft-maal” to guide insects. During many a year I could not believe in their meaning, until I found that their development was correlated with that of the nectary. see p 373 Cross-Fertilisation of Plants.)³

(Wiesner of Vienna has shown that Chlorophyll in young & tender parts is injured by an excess of light. & he believes that the red scales &c at end of shoots &c serve to protect the parts from those rays which are the most injurious.)⁴

p. 39 | Before you have another edition, pray consult good authorities, about 2 individuals of Cryptogamic Plants not intercrossing: I believe that you will find this dreadfully erroneous. In Fucus sexes often distinct. With Ferns. why should not male & female elements have been enclosed in same receptacle, except to allow of occasional crossing? & hybrid Forms have occasionally appeared.— Think again on the conjugation of distinct Algæ— conjugation being the precursor of sexual generation.— Pray read my discussion on the origin of sexes in last chapter of Cross Fertilisation.)⁵

p. 131 (I am now going to make a criticism beyond my tether; but I cannot believe in your theory of the origin of pleasure & pain; & I must think that these sensations have been specially acquired as a guide to each creature. Why sh^d the stimulation from Sugar give much pleasure to the gustatory nerves, & touching during the act of eating, not give pleasure to the delicate tactile nerves of the tongue & lips? If it had been highly advantageous to an animal that its lips sh^d be occasionally rubbed gently, then, I believe, the tactile nerves could have acquired pleasure in the act,— as in another part of the body, which need not be specified.⁶

(I am glad that you defend sexual selection: I have no fear about its ultimate fate, though now at a discount.— Wallace’s explanation of, for instance, the display of a Peacock seems to me mere empty words— For many years I have quite doubted his scientific judgment, though admiring greatly his ingenuity & originality.—)⁷

(D^r Hochberg (under the name of D^r Berg) lately sent me a pamphlet in German which I have only skimmed, but which seemed to me clever: he maintains, (somewhat like you about colour with ⁠⟨⁠birds and⁠⟩⁠ Butterflies) that the origin of sexual music is the ⁠⟨⁠3 or 4 words excised⁠⟩⁠ He also speculates on sense of ⁠⟨⁠3 or 4 words excised⁠⟩⁠ our progenitors having been fruit-⁠⟨⁠3 or 4 words excised⁠⟩⁠ ⁠⟨⁠se⁠⟩⁠cond note (asking me to get his paper translated ⁠⟨⁠3 or 4 words excised⁠⟩⁠ not do) he says he now finds that you have published similar views on colour.—)⁸

(I may mention that some years ⁠⟨⁠ag⁠⟩⁠o Fritz Müller expressed opinion in letter that the sight of beautiful flowers had influenced the sexual selection of Butterflies.— Before that I had speculated whether the sombre aspect of nature in Galapagos (under Equator) & in Patagonia had not destroyed taste for beautiful colours in the Birds of these Districts. I believe that I inserted a sentence to this effect; but I remember being frightened at such bold speculations, & perhaps struck out the passage.— The contrast in the colour of the birds in Patagonia, & on the bright-green, flower-decked plains of La Plata is very striking.—)⁹

I fear that you will hardly be able to decipher this letter (my Amanuensis is away)¹⁰ & perhaps not think it worth deciphering:—

I hope that you received my note acknowledging safe receipt of your Book.—¹¹