To Leonard Jenyns 22 February 1
Down. | Bromley. | Kent. S.E.
My dear Jenyns
It is long since we have had any communication & now I want ask a question on the chance of your being able to give me any information.2 But I ask on understanding that you have leisure & health to answer.
I want to know what British Birds are polygamous ie do not pair, so that one male wd suffice for more than one female. Would you run your eye down any lists of Brit Birds? I know only the pheasant, & am not sure of that. The query is in relation to the possession by the male of secondary sexual characters. I suppose such birds as blackbirds & bull-finches, in which the sexes differ in colour, pair strictly.— I presume pairing can be told by the male incubating & feeding young, & by the pair always associating during the breeding season. Do you suppose that a female blackbird or bull-finch would not breed if in any district the females were in excess over the males? If you can by chance throw any light on this subject I shd be grateful; or on the numerical relations of the two sexes in any Birds, whether males or females in excess.—
I hope that you are fairly well & continue to interest yourself in Natural History. For the last two years I have been considerably better, though far from well, & am able to do a good deal of work with sighs & groans in Nat. History; & as I never visit anywhere it is my sole amusement.—
What a loss poor dear Henslow has been.—3
Believe me | My dear Jenyns, | Yours very sincerely | Ch. Darwin
Have you any idea of the use of the horns in male Lamellicorn or coprophagous beetles?—
Asks LJ which British birds are polygamous. His query relates to the possession by the male of secondary sexual characters.
CD is also interested in the numerical proportion of the sexes in birds.
Asks about the use of the horns in male lamellicorn or coprophagous beetles.
Please cite as
Darwin Correspondence Project, “Letter no. 5911,” accessed on 25 August 2016, http://www.darwinproject.ac.uk/DCP-LETT-5911