My dear Darwin

Forbes is better I am exceedingly glad to hear, not able yet to leave his bed-room. His attack I suppose you know was ulceration of a (or the) kidneys— he has discharged a great deal of pus during micturation, but no mucus, so that there are yet considerable hopes. Really I do fear that his must be a very dangerous complaint & am deeply greived to hear of his suffering; poor fellow. Falconer told me he was very patient. I should wish much to see him, but do not like being obtrusive.

I asked about your numbers at the Brit. Mus. (of the Antarct. Zool.)¹ which is always there for you, & you are requested to send for your numbers when convenient, taking care to let them know what numbers you already possess, as they loose count. Also Reeves has one or more numbers of my flora for you,² I told him not to send them to me, as I have only to send them into Town again, if you like I will get those at the Britt. Mus. & leave them at Reeves or send them both any where you like in the course of the week.

Pray keep Webb & Berthelot for the present if you won’t for alltogether. The book wants more tabulated results greivously, but they are so difficult before the species are worked out & Webb is very cautious. Gaudichaud is a very good Physiologist, & a clever fellow, also a very nice man, but not a systematist, & I should not take his word for Volc. Insular floras being polymorphous. It is very easy saying so, & my contradicting it is only making matters worse if it is only because I do not see it; but I must confess I think all are following Bory.³ I hardly know which is easiest, for one who has not properly studied the subject to see evidences of the statements of another like Gaudichaud or to remark their absence as myself. I would not at all have you take my word for it; but I must say that I cannot see it to be the case, but the contrary. nor can it well be, if true that genera bear a large proportion to the species of Islands. It is possible that we may not mean the same thing by variable. Volc Islands are often lofty & steep & small, as Mauritius &c &c the consequence of which is that every species is found in several states at different heights; & from the confined area this at once strikes the observer, but I do not admit a Mt. state of a plant solely dependent on climacteric causes to be properly speaking a Variety, it is a state produced by assignable causes, & does not tend much to confusion of species. Nothing would be more impracticable than to make more than 16 species of the 16 Kerguelens’ Land plants. I should not call one of them polymorphous. Lord Auckland & Campbell’s Isld. possess but one variable genus Coprosma,. The St Helena plants are remarkably invariable, even the Ferns. The addition of other Galapagos plants to yours did not cause me either to do or undo any of the species founded on your materials. I will write to Webb about it;⁴ it looks very conceited to say so, but I really believe the fact to be that the Frenchmen do not know what Continental Floras are, they only study Insular ones (Bory, Gaudichaud Webb). Extended tracks of country with a large flora are full of polymorphous genera, even take Great Britain & there is scarce a Nat. Ord. without its bone of contention. However I will write to Webb tomorrow at any rate & take the opportunity of asking him to explain himself a little. Pray what is the case with animals?.

Is the shell common to both coasts of Am. confined to Panama on the W.? I alluded to the fact in my notes on Galapago Botany, it struck me as most curious & confirmatory of migration. Do you know any thing of a gulf stream from the Gulf of Panama running S.W. & meeting the great S. Polar current at the Galapagos,? there ought to be one.⁵ Have you seen Pet. Thouar’s Voy. of Venus & acct: of the different. temps. of the straits between the several Isld^s.? ⁶ Is it true what Douglass⁷ says that the Cactus of Jas Isld. grows 40 feet high?. he was apt to pull the long bow.

Anent the longevity of Trees, I was amazed at Lindley’s Doctrine, that they may live for ever, it is contrary to all analogy in the Veg. Kingdom; why do not herbs do so? no doubt it is very rare with Trees as it is with us, to die of sheer old age; there is generally an immediate cause. I am now however endeavoring to solve the mystery of an Ichaboe Plant that kills itself by turning all its bark into wax!—when the axis perishes & leaves a wax cast behind. Still I have no notion of apples &c dying out simultaneously, surely the evidence against that was reasonably conclusive. See how it is, that every one thinks all Evidence that goes with his preconceived opinion & all trivial that opposes it.

At present I endeavor to hold aloof from all speculations on the origin of species, & wish to till at any rate this part of my flora is finished. When that is the case I should like to have much talk about it with you, at present I go on the old assumption that each species has one origin is immutable & migrates. I am sore puzzled with two closely allied mundane genera (that trouble Volc. Islands very little) Gnaphalium & Senecio each are singularly widely diffused, but are differently affected with regard to varieties or rather to the relation the Sp. of one country bear to those of another. Sencio is made up of closely allied polymorphous species, but the species of no two countries are the same (generally speaking), the further you go from any centre, the more different the species become, the more they swerve from the typical forms of the country started from, there is no tendency in them to return either by variation to the old types, or by presenting analogous species, they display a centrifugal force. Gnaphalium on the other hand presents us in every country with many identical species & the typical species of each country always show a centripetal tendency to vary into one or two common types. Thus, the Chilian species of Senecio are unlike English, but the Fuegian & Patagonia are more so, but both the Chilian & Fuegia species of Gnaphalium are ever trying hard to become English, & succeeding too. This is an old story of Mundane genera &c, in one case a Mundane genus has mundane species the other has local species.

Please tell me again what you objections are to my use of sterile or abortive in Botany. I would wish to be accurate in the use of terms, but am at times hard up.

My Father says that the plants of Islands are not polymorphous as far as his recollection of Insular Floras goes, but that it is in extended areas that variable plants chiefly occur. The Andes or rather Cordillera flora is very bad, from its great amount of species, It probably also appears worse, from the actual area being so much greater than it appears when projected on a map. The more I consider the difference in trouble, between the Floras of Galapagos (or Auckland Isld) & of Fuegia (which is continental) the more convinced I am that the latter are the more polymorphous by far: trouble I mean in determining the limits of species, I still think there is no comparison in that respect:—the question is one of comparison.

I daresay you will think me very impertinent for suggesting to one of your experience on a subject of Geology; but as you are going to publish on that of S. Am. I would be so bold as to say, that I wish Geologists would give more maps & cuts, & especially maps of what the country is supposed to be during the epoch under consideration. It takes nearly a page to describe what country is under water & what above it when such & such a formation was depositing, all of which to such a tyro as I am, would read much simpler on a duodecimo map. In my tenderest years I used to pore over a map of the world before the flood! that gave me a wonderfull insight into geology as I then thought. How I should like a little map of the country between Plata & Horn before the 400 ft. were raised, another of the time when Icebergs roamed over the plains—another of 2 or 4 of the 8 periods of rest expressed by intensity of colors:—but I am rather out of my reckoning; only if you did think of it lithography would do it very cheap indeed.

My acct: of Kerg. Land Cabbage is extracted with notes in Chambers’ Journal,⁸ they conclude with rather pitying my ignorance in supposing there can be any reasonable mystery about its origin or that of any other plant, it being doubtless only a state of one of the seaweeds on the shore!— That’s Progressive Developement with a vengeance, or rather Developement per Saltum

Ever my dear Darwin Most truly Your’s | Jos D Hooker

Have you any tendency to subscribe £1’1, to a man who has been xloring Africa (Duncan)⁹ & is going again; I promised Capt Beaufort to ask some of my friends & want friendly help.