Discusses taxonomic relations of Alcippe.
25 Feby 1853—
My dear Sir,
I must apologize for having so long neglected to acknowledge the receipt of your long,
interesting & obliging letter of the
Regarding the rank that this animal should hold in the Classification is undoubtedly a matter of no little difficulty, and must depend upon the view entertained of the relative value of the differet organs. The cirri are certainly characteristic or important organs in the Cirripedia, and as they are in direct relationship with the mouth, consequently with alimentary system they must bear strongly on the general œconomy— Any modification of these organs will influence the development of the parts about the mouth, as indeed is proved by Alcippe. Such [ new devpts] would therefore appear of greater importance than variations of the capitulum or peduncle, the presence or absence of which latter does not seem to be of any signification— Looking in this way on the matter I arrived at the conclusion that the [ latter] cirripedes could not be placed with either the sessile or pedunculate groups, both of which I believe nearly coincide in the characters of the cirri and mouth.
Does not Alcippe differ in a more striking manner from the various genera of the Lepadidæ than these genera differ from each other;? if so it can scarcely be placed in this family—and in truth can scarcely be called pedunculate— if placed in the order of which the Lepadidæ is a member,—the characters of the order will have to be altered.
I have said this much to explain the motive that induced me to place Alcippe apart from the two great groups of cirripedes, but my knowledge of the Class is so imperfect that I have no great confidence in my own opinion on the subject. I am therefore well pleased that this curious animal is now in such competent hands, and have no doubt that you will find for it its proper place in the Classification, how difficult soever the task—
I have not yet succeeded in preserving more specimens; but will assuredly have a supply
this spring— I have spoken to two gentlemen who live on the coast and they
have promised to do their best— I shall also be frequently at Cullercoats myself—
Chas Darwin Esq
- f1 1505.f1See letters to Albany Hancock, 10 February , n. 4, and 12 February . CD did not alter the description of the Thoracica but merely made an exception for Alcippe. See Living Cirripedia (1854): 563–4, where Alcippe is contrasted with Cryptophialus.
- f2 1505.f2A village just north of Tynemouth, on the Northumbrian coast.