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 w^d 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 sh^d 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?—