Responds to JDD’s objections to his views on the three pairs of appendages in larvae of cirripedes. Reports observations which confirm his views.
Gives his confidential opinion of A. White, C. S. Bate, T. Bell, and W. Baird.
Interested in JDD’s observation that Crustacea are not most developed in the tropics. If JDD ever works it out either in number of species or rank, CD would be glad to have result.
Comments on article by Henri Milne-Edwards ["Crustacés", Ann. Sci. Nat. (Zool.) 18 (1852): 109–66].
Down Bromley Kent.
My dear Sir
I must thank you for your letter, received about a fortnight ago— It was extremely kind of you to write to Mr Lubbock, & I think he was much pleased & flattered at receiving your letter.—f1 I am very glad you mentioned your objection to my views on the nature of the three pairs of appendages in the earliest stage of cirripedes;f2 by an odd chance I was at the time searching for all sorts of evidence, & had just dissected the larva of an Hippolyte (sent me by Mr C. S. Bate) & as far as sequence goes, I find M. Joly’s views, that the three natatory pairs of legs are the 3 pairs of maxillipeds, are true for they closely follow the 2 pairs of jaws & mandibles.—f3
Since my former volume I have gone into the curious case of a S. American cirripede in which the larvæ in all the first stages are typified by an egg-like larva, with the pairs of anterior horns, & posterior horn including the abdomen: & in this case I actually dissected out of the anterior horns the usual prehensile antennæ, with every part perfect. Indeed it is very certain that the larva in the first stage has 2 pairs of antennæ in process of development;f4 a mouth as yet without the 3 pairs of gnathites; & the 3 pair of natatory legs, which may be, as in Hippolyte, the 3 pairs of maxillipeds, & Caridina, but which I fully believe are the 2d 3d 4th thoracic limbs.f5
I have entered all these points with care in my present volume; & I cannot say, how I shd be gratified if you could ever find time to criticise it. I presume I shall not get it printed for 4 or 5 months, but I will, when printed, of course send you a copy.f6 It will be more fully illustrated than the last.— I shd say that I have found many useful hints & cautions in your great work.—f7 By the way I have received the duplicate page.—f8
I am not much surprised at your correspondence with A. White having failed: I am told by some of his friends, poor fellow, that he has been for some considerable time, somewhat flighty in his head:f9 I have long perceived that though very clever, that he wd not do much from his fickleness.— There is, I hope, a rising Crustaceologist in Mr C. S. Bate (to whom I am soon going to lend your Book): he is an ardent observer, though I apprehend rather rash in theorising, & what is worse in observing: I suspect he trusts to the compound microscope & does not dissect enough, which I believe to be a fatal habit— He is intending to publish with Mr Westwood, a monograph of sessile-eyed crustaceans of Britain.f10 Bell is too busy ever I fear to do much;f11 he is a delightful, kind-hearted person. Dr Baird is a very goodnatured man, but rather indolent, & occupied with routine business at the B. Museum & I doubt whether very original,f12 and this includes, as far as I know, all the English Crustaceologists; & I have confidentially given you what I think of them.
Sir C. & Lady Lyell were staying here a short time since: they start in two days time for Madeira & the Canaries, to work out Craters of Elevation or of Denudation; & he is well charged with points to observe.—f13
To return to Crustacea were you not rather surprised at Milne Edwards new classification in the Annales for 185〈 〉?—f14 I was astonished at parts & could not at all, understand his reasons:— But I have an unbounded respect for M. Edwards as a Naturalistf15 From some old theoretical notions, I was interested by what you say about Crustacea not having been most developed in Tropics:f16 should you ever work this out in other branches, either in regard to mere numbers of species, or their rank I shd be particularly glad to hear the result. At one time Dr Hooker (who is a first rate naturalist, after your own heart) thought that a greater number of species of plants existed in the warmer temperate lands than under torrid zone; but he now doubts whether there are materials to determine this point.
Believe me, Your’s very sincerely & cordially | C. Darwin