is
to pick a bean from two baskets, each basket containing both white and
black beans in equal numbers. When at random one is taken from either of
these two baskets there is an even chance that the bean from the father
is white or black and an even chance that the bean from the mother is
white or black.

Now, what is the chance that the child draws a white bean from both
baskets? Evidently it is one chance in four; for there are four ways
equally probable in which you can take these beans, viz.: (1) black from
the father basket and black from the mother, (2) white from the father
and white from the mother, (3) white from the father and black from the
mother, (4) black from the father and white from the mother. So the
children could draw both white once in four times, both black once in
four, and a white and a black in the other two cases. And that is why
from two blue Andalusian fowls, on the average you will have one-quarter
of the children black, one-quarter white, and the other two-quarters,
blue. Again let us stop to emphasize the fact that the black children of
these hybrids are just as pure blooded as their black grandparent, and
will mate with other pure-blooded black in exactly the same way as
though there had never been any white in their ancestry. The white
strain has been left behind, or been "bred out."

We have spoken of one character or characteristic--color. The same laws
apply to other characters. Often different characters are inherited
quite independently of one another. Each of us is a basket or bundle of
very many qualities, each quality being a little compartment of the
basket with two beans in it. There is, as it were, a pair of beans for
every unit trait, whether that trait relates to color, to musical
ability, or to any one of hundreds of other kinds.

To summarize the laws of inheritance of the unit character called color,
in Andalusian fowl, we have really six ways in which we can consider
mating of the three colored fowls (black, white, blue): (1) black may
mate with black, in which case all the offspring will be black, (2)
white may mate with white, in which case all the offspring will be
white, (3) a black may mate with a white, in which case the offspring
will all be blue--a hybrid containing both black and blue elements, (4)
blue may mate with a black, in which case half the offspring will be
pure bred black, and half hybrid blue, (5) a blue may mate with a white,
in which case half the