Fanciers select their dogs, horses, pigeons, etc.
, for breeding, when nearly grown up.
They are indifferent whether the desired qualities are acquired earlier or later in life, if the full-grown animal possesses them.
And the cases just given, more especially that of the pigeons, show that the characteristic differences which have been accumulated by man's selection, and which give value to his breeds, do not generally appear at a very early period of life, and are inherited at a corresponding not early period.