To Albany Hancock [29 or 30 October 1849]
Down Farnborough Kent
My dear Sir
I have to thank you sincerely for many things. Your specimens arrived quite safe: I have as yet taken only a cursory glance at them; for I have an odiously tedious job of compiling long generic descriptions from my specific descriptions. When I have done in a fortnights time, I will enjoy the treat of having a good inspection of Alcippe; I hope by that time your Paper will be out, as it will save me much time in comparing every part with common cirripedia:—indeed I will wait till I can get the number with your Paper:—it is an immense time since I have seen a new form of Cirripedia.1 At same time I will look over my Mollusca & my few notes made at time;2 & if they turn out of slightest interest to you, I shall be heartily pleased by your acceptance of them. I will be careful of the specimens of Alcippe.— Your sketches are very spirited; the cirripede from Australia is the Ibla cuvierana;3 that from Madeira is an unnamed species, which I have unwillingly been compelled to make into a new & insignificant genus; I have called it (supposing name be not used) Machairis celata4 (from being encrusted with bark of the Antipathes): If you have any other cirripedes from foreign localities & wd allow me to examine them, it wd be of great service to me.—
Will you please to give my sincere thanks to Mr Alder for the specimens, & for the great trouble he has taken in copying Loven’s paper:5 it is a most interesting cirripede, & the type of a new family or order; for it has no relation to Alepas, the animal of which I know well: I must write to Loven;6 his description is unfortunately short.— Will you add to your kindness by some time asking Mr Alder to what place the Royal Academy of Sciences, given in the title belongs:7 Lady Lyell translates the Title, as “Extract from a Review of the Trans. of the R. Acad. of Sciences. 1st series 1844., p. 192–4” Secondly will you be so kind as to tell me on what being (for I cannot read word) your specimen of the Ibla is attached.8 And Thirdly whether you had any motive for calling your cirripede “Alcippe”, as perhaps I will change my long name of Arthrobalanus for a shorter one.—9 Anytime will do for an answer.—
With respect to Lithotrya:10 the shells have relation to diameter of hole, but the shell-parts of full-grown ones, I believe, project beyond their hole; this is hard to know as peduncle shrinks much from drying: holes are bored in all directions: the animal often rises of an inch in its hole from [DIAG WITHIN TEXT] thickness of cup: very young specimens have cups, I believe at earliest period: I cannot describe whole process of fixing in letter, but I must think it quite impossible that any cirripede can sink its basis in any object: I have thought that the larva of Lithotrya instinctively (is this not wonderful) creeps into the crevices of the coral-rocks to that depth, from which it can when nearly full-grown freely reach the surface; in interval I believe it feeds on infusoria in water circulating in the crevices. I once thought that the larva of Arthrobalanus might have bored its hole with its prehensile antennæ, but I cannot now believe this. But there is another view or conjecture, which perhaps is the most probable, viz that the larva (in 2d stage) boring a minute hole by an acid secreted from same glands, & through same duct & orifices in the prehensile antennæ (alluded to by me in Athenæum) by which afterwards the Cement-stuff is poured out:11 this view would perfectly harmonise with the facts, of which I cannot doubt, namely that the cirripede after metamorphosis can never alter its point of attachment & secondly the apparatus of minute points for enlarging its cavity, in Lithotrya Arthrobalanus & Alcippe, is equally applicable.—
But I shall utterly weary you with this discussion.— Your statements about cavities of Alcippe make me doubt my view of the larva creeping into already existing cavities.—
With my sincerest thanks | Your’s very faithfully | C. Darwin
Thanks him for specimens of Alcippe.
Comments on sketches by AH and on cirripede paper by Lovén.
Discusses Lithotrya and its burrowing habits.
Please cite as
Darwin Correspondence Project, “Letter no. 1262,” accessed on 5 December 2016, http://www.darwinproject.ac.uk/DCP-LETT-1262