rossed, young birds were continually produced,
more or less plainly coloured slaty-blue, with some or all of the
proper characteristic marks. I may recall to the reader's memory one
case, namely, that of a pigeon, hardly distinguishable from the wild
Shetland species, the grandchild of a red-spot, white fantail, and two
black barbs, from any of which, when purely-bred, the production of a
pigeon coloured like the wild _C. livia_ would have been almost a
prodigy.

I was thus led to make the experiments, recorded in the seventh
chapter, on fowls. I selected long-established, pure breeds, in which
there was not a trace of red, yet in several of the mongrels feathers
of this colour appeared; and one magnificent bird, the offspring of a
black Spanish cock and white Silk hen, was coloured almost exactly like
the wild _Gallus bankiva_. All who know anything of the breeding of
poultry will admit that tens of thousands of pure Spanish and of pure
white Silk fowls might have been reared without the appearance of a red
feather. The fact, given on the authority of Mr. Tegetmeier, of the
frequent appearance, in mongrel fowls, of pencilled or
transversely-barred feathers, like those common to many gallinaceous
birds, is likewise apparently a case of reversion to a character
formerly possessed by some ancient progenitor of the family. I owe to
the kindness of this same excellent observer the inspection of some
neck-hackles and tail-feathers from a hybrid between the common fowl
and a very distinct species, the _Gallus varius_; and these feathers
are transversely striped in a conspicuous manner with dark metallic
blue and grey, a character which could not have been derived from
either immediate parent.

I have been informed by Mr. B. P. Brent, that he crossed a white
Aylesbury drake and a black so-called Labrador duck, both of which are
true breeds, and he obtained a young drake closely like the mallard
(_A. boschas_). Of the musk-duck (_A. moschata_, Linn.) there are two
sub-breeds, namely, white and slate-coloured; and these I am informed
breed true, or nearly true. But the Rev. W. D. Fox tells me that, by
putting a white drake to a slate-coloured duck, black birds, pied with
white, like the wild musk-duck, were always produced.

We have seen in the fourth chapter, that the so-called Himalayan