My dear Darwin

Very many thanks for your letter.² You ask several questions in it, which I will at once get off my mind.

I did not mean to assert that when one of a pair of Crows—Magpies &c is shot & replaced, “it is always the male”. In all the cases I have met with, or heard of, it has been the case, and for this reason possibly, that the Male Bird in Crows & Magpies, seems, until the young are hatched, continually engaged in collecting food for the female & conveying it to her on the nest, where she receives it with much the same demonstration of satisfaction, as young Rooks do.

There is no difficulty whatever in recognizing the Male Birds of either Crows or Magpies, and any keeper w^d do so easily; but they also know them from the fact I have mentioned of their continually going to & from the nest to feed the incubating female,—and in doing this they are generally shot by the waiting Keeper, who knows of the nest.

The best way to ascertain about the sex of the shot & replaced Bird, would be to try the experiment with Rooks. Each sex might easily be shot in any Rookery where the trees are young—and the difficult fact as to where the single Birds come from to replace the shot ones, might be more easily traced in a Rookery than elsewhere.

Rooks so much resemble Carrion Crows, that I have no doubt similar phenomena would shew themselves in both.³

I have little doubt that you will find the numerical relations of the sexes in birds & beasts, as nearly as possible coincide, if your tables are large enough. In single cases they differ largely—but in the aggregate, will, I think be found to be nearly equal. In domestic poultry some years in a flock of Turkeys the Males preponderate often largely—but I have noticed that the next year the Hens are in the ascendant as much.

The Swan Goose is the China Goose. L Jenyns gives it that name from Bewick, and it so well describes the Bird, which is really quite an intermediate species, that I always call it so.⁴

I have today examined exactly into the facts respecting the hybrid Geese, which are not quite as I stated them in last letter. The old ones—were 1 common Gander with 3 Common Geese. 1 white China Gander with 1 white do Goose. The two latter were paired, and the other four kept together, until the China seduced one common Goose to live with him, and occasionally made inroads into his Neighbours Harem besides. 1 common Goose produced no young ones   The white China brought 3 pure bred China only— The other two common brought out 4 common Geese and 18 half bred Common & White China. There is no possibility of doubting about the cross, as they are far more Chinese than common—with long swan necks, & beautiful birds. Both the Common Geese which hatched, must have played false—the one which hatched none, of course I cannot accuse of incontinency.

The cross is so superior in size & beauty, that I am killing off the common Gander & mean to have no others but $\frac{1}{2}$ breeds.

I told you I have a white China Gander most affectionately paired with a Canada Goose. Now for the sexes of sheep—Cows &c as far as I can give them. I shall go backwards for convenience.

This is a very beggarly Table—but I find I c^d not give correct lists of other years.

Merino sheep I know nothing whatever about. I am not sure that I ever saw one.

Did I tell you of a Herd of Cows at Trusley in Derbyshire—where last year 33 cow calves came to 1 Bull. (I feel sure this was the proportion, but will write & ask, if worth while to you. (I have since found my mem^a made at time from E Fosters lips—the Farmer they belonged to.)⁵

I have been delayed horribly in forwarding this by a multitude of causes— Terrible illness in Parish— The horrible Election which took me nearly a week to vote twice for liberals⁶—& a host of other things—which made it impossible to see another Keeper I wanted to.

I missed him 2ce—but caught him on Saturday. He has never observed that either crows or magpies ever are replaced when one is shot⁷—but he has known Cock birds go on sitting the eggs after he has killed the hen bird & hatch the young. He has also seen the Magpie gatherings early in Spring—or rather in Winter in the Forest, & that they were all paired afterwards.

To give you an idea of the number we used to have here, he once killed 7 Magpies at a shot out of a fir tree—while roosting.

Very many thanks for your kind expressions of regard &c about my health. I have been better during the last month, & have done a good deal. I am tomorrow going to M^r Woodds at Hillfield with my wife to stay a few days—see my Sisters—D^r &c.⁸ Were the time of year rather more favourable I w^d have tried to accept your kind invitation.⁹ I sh^d much like to have a day with you once more, and again see M^rs Darwin. I hear you are having a Bust made—at which I rejoice.¹⁰

Kindest regards to M^rs & Miss Darwin¹¹ | Ever yours, W D Fox

Dec^r 9.