From W. B. Tegetmeier 29 June – 7 July 18631
Muswell Hill | London. N.
July 7— 63.
My dear Sir
I thought that you might like to hear some of the results of the experiments that I have been trying, respecting the fertility of Mongrels.2
I have crossed three pair of Black Barbs and White Fantails, and am keeping the offspring for breeding next year.
The plumage has in all cases taken more after the male than the female parent.— In no case has there been any sign of want of fertility—3
In accordance with your suggestion I have also experimented on the Silk fowl and Spanish Cross with A very good pure bred Spanish Cock and two rather old Silk fowl hens.—4 Only one of these laid. 9 eggs. They were left in the nest and she sat, producing 9 chicks, all black plumage, violet black skin.— Obviously identical with the Coq. Nêgre of Temminck—5 None, even slightly, silky
I shall keep a cock and several pullets for breeding next season— Other fowls will breed for 5 or 6 seasons on end in breeding without a fresh cross, if these do not do the same it will be an indication of greater sterility in these mongrels than in pure breeds.6
There were some paragraphs in the Field the other day respecting all blue-eyed cats not being deaf, as I think you have stated.7 If you have not seen the correspondence I will cut it out and forward it to you.
I forward you by this same post a number of the Intellectual Observer containing a short article of mine on Variation in Plumage at page 173—I have endeavoured to account for the circumstances that no small birds exist in a wild state with silky plumage but hardly expect that the idea has not occured to you.8
Trusting to hear that you are in good health | Believe me | Yours faithfully | W B Tegetmeier
C Darwin Esq
Progress of pigeon and poultry breeding experiments. No loss of fertility observed yet.
Blue-eyed cats and deafness.