To J. D. Hooker 13 June 
Down Farnborough Kent [Malvern]
My dear Hooker
I was very much pleased to get your last letter,1 received about a fortnight ago; I cannot remember its date & it is locked up with your others at Down; I am writing this at Malvern, whither I have come for a week of extra aqueous treatment. You thank me for my letters,—you apologise for not having written oftener to me, & in doing both, you stab me & remind me how neglectful I have been about letters; but my case is too bad for apologies, so I will say no more.—
Your verses on stratification are capital, & I feel their truth even more than when I wrote my S. America (N.B that you shd. have read that book, not to mention the cold & numb (how is this spelt?) fingers, is to me in truth wonderful & most flattering.): what strata are in the metamorphic schists I do not pretend even to conjecture; some facts make me suspect that many of the apparently truest strata of quite distinct mineral matter are perhaps gigantic lens-shaped concretionary masses—“and cleavage is as bad”—!— I have little doubt that you are quite right in your suspicion that the strata on borders of the mountains have been fairly inverted: Rogers in U. States has shown that this is a quite common, & almost usual case;2 though the manner of action remains quite unexplained.— I am delighted to hear that you have traced moraines down from actual glaciers: in my eyes your facts form an important discovery; for I believe there has been no evidence of glacial phenomena, or of their effects in erratic blocks, East of the Ural. Certainly the existence of the glacial period so lately forms one of the grandest discoveries of late times.— How much you seem to have attended to Geography in its highest meaning: with respect to rivers penetrating transversely the higher of two parallel chains, I have always thought it a strong presumptive argument that the breached chain was the younger or subsequently raised one;—I do not know how this bears on your views.—
By the way you sometimes speak of other people having philosophical minds, as if you had nothing of the sort; now this is one of the greatest falsehoods ever told by implication,—read your own Galapagos paper3 & be ashamed of yourself— compare any half-dozen-pages of the Antarctic Flora4 with other systematic works, dull as they generally are, & you will never have the face to depreciate yourself again.—
With regard to myself I have not been quite so well for some months past,—though the sickness has not come on, & my life altogether is bliss compared to what it was formerly: I find I do not improve in strength to withstand excitement; but my Water Doctor continues to give me hopes & I am got absolutely to like my aquatic life except the dressing & undressing. Everyone tells me that I look quite blooming & beautiful;—& most think I am shamming, but you have never been one of those.
At last I am going to press with a small, poor first fruit of my confounded cirripedia, viz the fossil pedunculated cirripedia.5 You ask what effect studying species has had on my variation theories;6 I do not think much; I have felt some difficulties more; on the other hand I have been struck (& probably unfairly from the class) with the variability of every part in some slight degree of every species: when the same organ is rigorously compared in many individuals I always find some slight variability, & consequently that the diagnosis of species from minute differences is always dangerous. I had thought the same parts, of the same species more resembled than they do anyhow in Cirripedia, objects cast in the same mould. Systematic work wd be easy were it not for this confounded variation, which, however, is pleasant to me as a speculatist though odious to me as a systematist.— Your remarks on the distinctness (so unpleasant to me) of the Himmalaya rubi willows &c compared with those of N. America &c are very interesting; if my rude species=sketch had any small share in leading you to these observations, it has already done good & ample service, & may lay its bones in the earth in peace.—
I never heard anything so strange as Falconer’s neglect of your letters: I am extremely glad you are cordial with him again, though it must have cost you an effort. Falconer is a man one must love— pray give him my kindest remembrances.— Dr. Malcolmson, the geologist, is certainly dead.— I have seen no one of late. I hear from my Brother that Kew is looking in very great beauty. May you prosper in every way my dear Hooker
Your affectionate friend | C. Darwin
On Himalayan stratigraphy. Believes JDH’s observations of glacial action are the first ever done east of Urals.
Barnacles and the species theory; impressed with variation.
Effect of CD’s species sketch on JDH’s view of willow systematics.