Ingredients -One black Australorp male from a good egg-laying strain. One or more, according to taste, Barred Plymouth Rock females, Instructions -Mix well in a pen of suitable size. After a week or so collect and incubate the eggs. About half of the chickens which hatch will have black down with a white head spot, indicating one barring factor. When grown up these will be barred and cockerels; which are delicious when roasted with potatoes, carrots and onions. As a purist as well as a gourmet, I add green peas to the meal (in memory of Gregor Mendel.) The other chickens will have dark down and no head spots. They are pullets which will grow into black hens; whose eggs are very tasty, whether boiled, fried or poached. These hens will also have inherited, through their father, some of the good egglaying capacity of their Australorp grandmother.
The black Australorp male who is their father can pass on characteristics, such as egglaying ability, which he himself cannot express. Egglaying is a sex-limited factor. An example in humans of one factor which is sex-limited is that I, as an adult male, grow whiskers, whereas the girls, as they mature into the full flowering of womanhood grow --- more interesting, at least to me.
When fowls have black patterning, such as the Silver Laced Wyandotte and the Dark Indian Game, it is still obvious whether their ground colour is silver or gold. With the all black Australorp it is not. Yet they have sex chromosomes, of which each of the X chromosomes is either a silver or gold and is passed, without its presence being apparent, from each generation to the next, according to the rules of sex-linked inheritance. Even the non-sex-linked characteristics on the autosomal chromosomes, are passed without becoming visible, from parent to offspring, in the self black chooks. Thus any all black fowl can be a black Columbian, i.e. with black neck and tail feathers on a black background; or a black laced back, with black lacing against a black background. In this world many things are not seen by the eyes of men, even married men. The astute breeder will cross a self black fowl with, say a buff bird to reveal what patterns and colours lie beneath those black feathers. To breed Australorp to Australorp for twenty or thirty years must be like treading water endlessly without ever swimming a single stroke.