"showed a perfect obstinacy in sitting." The Rev. E.S. Dixon ('Ornamental
Poultry' 1848 page 200) says that chickens reared from a cross between Golden
and Black Polish fowls, are "good and steady birds to sit." Mr. B.P. Brent
informs me that he raised some good sitting hens by crossing Pencilled
Hamburgh and Polish breeds. A cross-bred bird from a Spanish non-incubating
cock and Cochin incubating hen is mentioned in the 'Poultry Chronicle' volume
3 page 13, as an "exemplary mother." On the other hand, an exceptional case is
given in the 'Cottage Gardener' 1860 page 388 of a hen raised from a Spanish
cock and black Polish hen which did not incubate.) Another author, after
giving a striking example, remarks that the fact can be explained only on the
principle that "two negatives make a positive." It cannot, however, be
maintained that hens produced from a cross between two non-sitting breeds
invariably recover their lost instinct, any more than that crossed fowls or
pigeons invariably recover the red or blue plumage of their prototypes. Thus I
raised several chickens from a Polish hen by a Spanish cock,--breeds which do
not incubate,--and none of the young hens at first showed any tendency to sit;
but one of them--the only one which was preserved--in the third year sat well
on her eggs and reared a brood of chickens. So that here we have the
reappearance with advancing age of a primitive instinct, in the same manner as
we have seen that the red plumage of the Gallus bankiva is sometimes
reacquired both by crossed and purely-bred fowls of various kinds as they grow
old.

The parents of all our domesticated animals were of course aboriginally wild
in disposition; and when a domesticated species is crossed with a distinct
species, whether this is a domesticated or only a tamed animal, the hybrids
are often wild to such a degree, that the fact is intelligible only on the
principle that the cross has caused a partial return to a primitive
disposition. Thus, the Earl of Powis formerly imported some thoroughly
domesticated humped cattle from India, and crossed them with English breeds,