Dear Paget

I am heartily obliged for your present, but hardly feel worthy of it. I was so very much interested by many things which you told me, that you may be sure I shall read your Lectures;² but I shall not be able very soon, as I have several big borrowed books, which must be returned soon. Will you be so very kind as to remember me, if anything occurs to you, in regard to inheritance at corresponding or rather earlier ages; & in regard to constitution & complexion.—³

I wish I could give you any facts on your Chronometry of Life;⁴ I am sure I have often met with striking facts; but I have disregarded such facts & deviations alone would have struck me.

You know of course that the same bird in state of nature further S. or N. lays eggs at different times; & not rarely 2 broods in the S. & only one in N. The degree to which they sit, varies under different temperatures; but I do not mean by this that eggs hatch at different periods.— Some Batrachians of same species are oviparous or ovoviviparous under different climates. The periodical shedding of wool in sheep is no doubt affected by tropical climate. The appearance of second teeth has been greatly affected & accelerated in our domestic quadrupeds. Certain breeds of fowls, acquire their perfect plumage slower than others, so that after the down they are apt to be almost naked.

I see Youatt does not seem to doubt that period of breeding has been accelerated with the general early maturity of our improved cattle.⁵ Tessier gives 321 days as longest period & 240 as shortest period of gestation in cattle.⁶

I do not suppose these rough remarks will be of any interest to you, but I send them for mere chance

Pray believe me, with very many thanks | Yours sincerely | Ch. Darwin

Cocks can be distinguished from Hens, earlier in some breeds than others.