My dear Gray.

I have just received your most kind letter of Aug 18 & 19^{th 2} & will amuse myself, now my patients are in bed,³ by beginning a letter to you. My poor Boy (whose waxen face blushed up to the eyes at the thought of writing to a live Professor)⁴ has this day made a marked step & has taken several walks of a few hundred yards; & my wife is recovering well & her skin well peeling.— We have taken two houses here, so I hope & trust this dredful fever will not spread.—⁵ I am very glad that at present you intend to publish some separate notes on orchids, which you have so capitally worked out.⁶ No doubt I am not a fair judge; but I must think that it is worth your while.— I am pleased to hear about Goodyera & about Gymnadia tridentata. Your account makes me think the latter like the Bonatea speciosa & often & often have I speculated what on earth could be meaning of its wonderful horn-like stigmas & projecting anthers.⁷ I suspect its structure may have been arrived at by a process somewhat analogous to that which apparently has produced the wondrous nectary of Angræcum sesquipedale.⁸ It would appear that self-fertilisation is commoner than I thought: since publishing I have found that Neottia nidus-avis fertilises itself, if insects fail to do the job.—⁹ Many thanks for Houstonia seed.—¹⁰

I am glad to hear, but disappointed, about the Specularia pollen-tubes.¹¹ I cannot resist sending you a diagram about Lythrum (why should I resist? does not prescription give a right? & have I not for long years written & bothered you about all sorts of things?) Lythrum has 3 kinds of stigmas & 3 kinds of pollen; the stamens of same height on two of the three forms producing the same sort of pollen, & I cannot doubt are fitted to fertilise the stigma of that height. I conclude so from watching the Bees; but hope to prove it by my crosses. So that we have three hermaphrodite forms each depending on half the stamens of either one of the two other forms. This is shown by the lines with the arrows. This strikes me as a very curious case. The three forms coexist in about equal numbers. By the way it seems to me that Lindley in Veg. Kingdom describes the homological structure of flower wrong:¹² the so called calyx, with its 12 bundles of spiral vessels, appears to consist of 6 narrow sepals & 6 modified petals, all cohering; & that the coloured petals belong to an inner whorl & are modified stamens. By the way can you tell me of any flowers, with fertile anthers of different colours; I believe that this would be pretty sure guide to dimorphism or trimorphism.—¹³

All my semibotanical work, as you know, has been connected with insects, & now I am almost sure (but I find it a disgusting truth that with me first observations are generally all a blunder) that flowers have led me to a curious little discovery with respect to the best-known insect in the world, the Hive Bee. I saw the other day to my dismay (see Origin) Hive Bees sucking the common red clover, but it was a second crop, which I am told produces shorter flowers;¹⁴ but many of the Bees never attempted this, but always inserted their heads between the flowers & sucked at holes bitten through the corolla.— The same bee always followed the same practice. And apparently those which suck at the mouth of the flower have a longer proboscis than the other bees, which suck through the holes.

Farewell my dear Gray, forgive me scribbling about my own work; for I seldom see a soul to talk with on natural history.

Good night— Ever yours most truly | C. Darwin

Since writing the above by Jove I have found I have as usual at first blundered about the probosces; but if you had seen the Bees, the blunder was almost excusable—¹⁵ What an ass I was to scribble all the above.—

Progress of Education.— one of my little Boys Horace¹⁶ said to me, “there are a terrible number of adders here; but if everyone killed as many as they could, they would sting less”.— I answered “of course they would be fewer”   Horace “Of course, but I did not mean that; what I meant was, that the more timid adders, which run away & do not sting would be saved, & after a time none of the adders would sting”.—

Natural selection!!

¹⁷