themselves uniform in character,
when paired together they yield during many generations offspring
astonishingly diversified. The breeder is driven to despair, and concludes
that he will never form an intermediate race. But from the cases already
given, and from others which have been recorded, it appears that patience
alone is necessary; as Mr. Spooner remarks, "nature opposes no barrier to
successful admixture; in the course of time, by the aid of selection and
careful weeding, it is practicable to establish a new breed." After six or
seven generations the hoped-for result will in most cases be obtained; but
even then an occasional reversion, or failure to keep true, may be
expected. The attempt, however, will assuredly fail if the conditions of
life be decidedly unfavourable to the characters of either
parent-breed.[208]

Although the grandchildren and succeeding generations of cross-bred animals
are generally variable in an extreme degree, some curious exceptions to the
rule have been observed, both with crossed races and species. Thus Boitard
and Corbie[209] assert that from a Pouter and a Runt "a Cavalier will
appear, which we have classed amongst pigeons of pure race, because it
transmits all its qualities to its posterity." The editor of the 'Poultry
Chronicle'[210] bred some bluish fowls from a black Spanish cock and a
Malay hen; and these remained true to colour "generation after generation."
The Himalayan breed of rabbits was certainly formed by crossing two
sub-varieties of the silver-grey rabbit; although it suddenly assumed its
present character, which differs much from that of either parent-breed, yet
it has ever since been easily and truly propagated. I crossed some Labrador
and Penguin ducks, and recrossed the mongrels with Penguins; afterwards,
most of the ducks reared during three generations were nearly uniform in
character, being brown with a white crescentic mark on the lower part of
the breast, {98} and with some white spots at the base of the beak; so that
by the aid of a little selection a new breed might easily have been formed.
In regard to crossed varieties of plants, Mr. Beaton remarks[211] that
"Melville's extraordinary cross between the Scotch kale and an early
cabbage is as true and genuine as any on record;" but in this case no doubt
selection was practised. Gaertner[212] has given five cases of hybrids, in
which the progeny kept constant; and hybrids between _Dianthus armeria_ and
_delto