This was re-printed from the Poultry Manual by the Rev. T. W. Sturges, London, MacDonald & Evans, 1911.

One of the most interesting and intricate examples of the action of black and yellow is found in the breeding of Black Leghorns. Here the aim of the breeder is to breed a bird with a dense black plumage, but with a yellow leg and beak in either sex.

As a general rule, the distinct parts of a bird are inherited separately and independent of each other, and leg colour or skin colour, e.g. a Black-red Game may have legs black, willow, tallow or white. The natural colour of the legs of a black fowl is either black or dark slate, or willow or bronze. But when an attempt is made in introduce yellow legs is made, the parts become correlated, and the yellow leg attacks the black plumage and destroys its intensity and produces white, more especially in those parts which are the black pigment’s special domain, the flights and the tail.

For some reason so far unexplained, the yellow leg is easy to breed in the cockerel, and when the yellow is intense the plumage is light in under-colour, and white appears in the flights and tail. The black pigment appears to be lacking in the male, and the yellow pigment strong, and that in the longest feathers, more especially the two long sickle feathers. The black pigment appears to be exhausted before the feathers have reached their full growth, and the result is white at the base of the feather in nearly all cases, and frequently along its entire length, except at the tip.

On the other hand, the black pigment is strongest in the hen, and the yellow pigment deficient, so that the female has naturally dense black plumage, with dense black under-colour, but with legs either black or bronze colour, with faint trace of yellow showing in the shank, and yellow between the toes and on the bottoms of the feet.

The breeder’s aim is to transfer the yellow pigment of the male bird to the hen, so that she may have yellow legs and beak, and to impart through the hen the black pigment to the cock, so that he may be sound in this black plumage.

This feat has been accomplished many times in the case of the female. Every year, now, pullets are shown with dense and brilliant black plumage, and with good yellow legs. In the case of the cock it has rarely, if ever, been done to perfection. Sound black plumage has been seen on all parts except at the roots of the sickle feathers, and very many specimens are exhibited with absolutely sound black plumage INCLUDING the sickle feathers, when the latter have not been fully developed. But in majority of cases, if not in all, when the cockerel has good yellow legs, the fatal white appears when the sickle feathers arrive at maturity.

There have been cases when the entire black plumage, fully developed, has been seen, but, in such cases, the leg colour has been deficient in yellow pigment, which is manifested either in the legs being of a willow cast or a bronzed shade, or with a good yellow legs spotted with black.

TO BREED EXHIBITION COCKS the male is selected with the best coloured legs and beak obtainable, and, of course, with good head points, such as correct form of lobe and comb, and with colour as sound as can be obtained after the leg colour, etc., has been found. The hens to mate with him are selected for soundness of under-colour as their chief point; leg colour, while as good as can be found, being a secondary consideration.

TO BREED EXHIBITION HENS the cockerel should be chosen with good yellow legs, orange colour, if possible, and with as good plumage colour as is found compatible with this. There is sure to be some white in the tall, and white in under-colour of plumage – the yellow pigment has destroyed the black – but this is of little consequence. And if the hens he is mated with have good plumage it matters very little. Indeed, I have known good pullets bred from a cock white as snow in under-colour, and with a tail showing much white both in the sickles and tail coverts.

The point to be chiefly considered is the proportion of the various pigments. If the cock is fairly sound in colour and has good yellow legs, the density of the hen’s plumage is of less consequence if the legs are yellow.

It is possible to breed exhibition specimens of both sexes from the same pen. But there will always be a conflict between the yellow of the legs and the black of the plumage. Another simple way of breeding both sexes from the same pen is to have a cock-breeding cock and a pullet-breeding cock to the same pen, and allow the birds to run in the breeding pen on alternative days – the cock-breeder to be chosen for soundness of plumage, and the pullet-breeder for abundance of yellow pigment, as indicated by good legs an beak, with light under-colour. This is much cheaper than buying two breeding pens.