Mr dear Sir,

I thank you sincerely for your long & most interesting letter, which I should have answered sooner had it not been delayed in London.¹ I had not heard before that I was to be proposed as a Corr: Member of the Institute.² Living so retired a life as I do, such honours affect me very little; & I can say with entire truth that your kind expression of sympathy has given, & will give me much more pleasure than the election itself, should I be elected.

Your idea that dicotyledonous plants were not developed in force until sucking insects had been evolved seems to me a splendid one.³ I am surprised that the idea never occurred to me, but this is always the case when one first hears a new & simple explanation of some mysterious phenomenon. It’s the old story of Columbus & the egg.⁴ I formerly showed that we might fairly assume that the beauty of flowers, their sweet odour & copious nectar, may be attributed to the existence of flower-haunting insects but your idea, which I hope you will publish, goes much further & is much more important.⁵ With respect to the great development of mammifers in the later Geological periods following from the development of dicotyledons, I think it ought to be proved that such animals as deer, cows, horses &c could not flourish if fed exclusively on the gramineæ & other anemophilous monocotyledons; & I do not suppose that any evidence on this head exists.⁶

Your suggestion of studying the manner of fertilisation of the surviving members of the most ancient forms of the dicotyledons is a very good one, & I hope that you will keep it in mind yourself, for I have turned my attention to other subjects. Delpino I think says that Magnolia is fertilised by insects which gnaw the petals, & I should not be surprised if the same fact holds good with Nymphaea.⁷ When ever I have looked at the flowers of these latter plants, I have felt inclined to admit the view that petals are modified stamens & not modified leaves; though Pointsettia seems to show that true leaves might be converted into coloured petals.⁸ I grieve to say that I have never been properly grounded in Botany & have studied only special points: therefore I cannot pretend to express any opinion on your remarks on the origin of the flowers of the Coniferæ, Gnetaceæ &c; but I have been delighted with what you say on the conversion of a monœcous species into a hermaphrodite one by the condensations of the verticels on a branch bearing female flowers near the summit & male flowers below. M^r Thiselton Dyer, in a review of my book in Nature, objected on morphological grounds to a somewhat similar notion; but did not explain what these grounds were.⁹

With respect to persistent types your cases are curiously analogous to those which occur in many groups of the animal kingdom & have been commented on by Huxley.¹⁰

I expect Hooker to come here before long, & I will then show him your drawing & if he makes any important remarks I will communicate with you.¹¹ He is very busy at present in clearing off arrears after his American expedition, so that I do not like to trouble him even with the briefest note.¹²

I am at present working with my son at some physiological subjects & we are arriving at very curious results, but they are not as yet sufficiently certain to be worth communicating to you.¹³ I do not know whether you feel any interest about insectivorous plants: my son Francis fed with meat last summer a large number of plants of Drosera rotundifolia & left others unfed by excluding insects; & the difference between the two sets of plants in growth, & especially in the number & weight of the seeds was truly wonderful. He has sent a paper on this subject to the Linnean Soc a copy of which he will hereafter send to you.¹⁴

With my best thanks & the greatest respect, I remain, my dear Sir | Yours faithfully