From J. D. Hooker 8 November 1844
West Park Kew
Friday Novr 8. 1844
My dear Darwin
The accompanying are almost verbatim copies of the notes on Infusoriæ in my Journal: are they not luminous?!— I did think of dressing them a bit, but changed my mind; if they are worth any thing they are better as authentic— I have added an idea of my own of the formation of Pancake ice,1 I never read an xplanation of it, but Ehrenberg seems to have been so puzzled about it in his former letters, that I thought I had better initiate him a little into the mysteries of the S. Pole.— I dare say he will think me very presumptuous for this & some other parts of these notes, but I give him them as I found them & he may make any use he can of them, providing he will promise to look on them as they really are—crude remarks made on the spot.
The figures referred to I will copy when the drawings are accessable, but they are now at Edinburgh in Goodsirs hands, who is doing the Crustacea, & have been there a long time..2 The little story at the end about the Ice in columns I intend for you, & not for Ehrenberg’s edification; though as I carelessly wrote it on the same sheet, he will have the benefit of it— I am presuming that you will read the ponderous mss. & forgetting that you are not a Kopfnüsse German. 3
I have not forgot a question you once propounded to me as to whether the species of large-groups-which-were-local were local also, & am inclined to think that species of local large nat. ords. are local also, Cacti I think I mentioned before as an example & Proteaceæ & Epacridæ I take to be two others.
I find two fruitful sources of error into which specific Botanists fall, one is the describing two things as new, because they come from 2 far off countries; & the other of uniting 2 species because they come from the same. To a certain extent a safeguard will be the consideration of whether the group to which the individual belongs is local or widely diffused:—thus, I should hesitate to join two Proteaceæ because they both come from Australia, longer than I should to join two Cardamines one from England & the other from Australia— If this caution saves one single species, the Athenæum need no more cry “cui bono” to poor Watsons Geog. Distrib. of British plants.—4
I find Lycopodiums the same all over the world they do vary miro modo.. atmospheric & other causes have made (what have passed for) many species of them. How is this?, I am firmly convinced (but not sure enough to print it) that L. Selago varies in V. D L. into L. varium—two more different species (as they have hitherto been thought) per se can not be conceived, but no where else do they vary into one another nor does Selago vary at all in England.—5 I am perfectly aware of the xtreme caution that should be used in this instance, & the propriety of keeping the two species distinct in V. D L., or finding some character between the V. D L. form of varium which appears there as Selago,—if in either case, any, however slight, a character can be found between them; but I can find none, the V. D L. Selago is, to my eyes, identical with the English & V. D L. appears to me to possess all intermediate states between selago & varium: this is not the passage merely of one species into another, but of two groups of the genus differing originally toto caelo.. If I can only find a parallel case in the genus (& it is a weeks work to get the species together), I will be down upon varium very soon.
I do not know why I should bother you with these things xcept that you always take it so kindly:
My Father joins me in most kind remembrances to Mrs Darwin & believe me ever | Yours most truly | Jos D Hooker
P.S. The drawings referred to are not worth any thing but only shew what form of infusoria I refer to.—
If you go towards the Ship inn Charing X you can see by asking the waiter a very fine plant of Tussack belonging to Capt Ross.6 I enclose you some good seeds, we have plenty young plants from them..
Sends notes on Infusoria for Ehrenberg.
Comments on distribution of species in natural orders that have local distributions. Intermediate forms between species of Lycopodium.
Please cite as
Darwin Correspondence Project, “Letter no. 788,” accessed on 27 March 2017, http://www.darwinproject.ac.uk/DCP-LETT-788