rests upon its novelty in regard to British authorities*. The
case, it must be owned, is one of a rare land, and, though
certainly not singular in ornithology, we have at present to
go to India or the heart of North America to find its
parallels!. Yet its rarity is no valid objection. If there he
any degree of truth in the theories which have of late years
been so prominently set forth, such cases must at one time
or another have been countless; hut to discuss those theories
would here be out of place. All that is now required is
to consider, with the utmost fairness, the peculiar characters
of each form under every aspect—whether of structure,
coloration, habits or distribution, and then to test their
value in regard to the admitted fact of the frequent interbreeding
of the two forms where they both occur, as well as
to the indisputable results of that interbreeding. For this
purpose it will be convenient to invert the order generally
followed in the present work, and first to describe each form.
In the technical sense of the term not an atom of structural
difference has been found between the Black and the
Grey Crows. Taking in hand a typical specimen of each
there is nought to distinguish them but colour. The Grey
Crow varies in size as it varies in shade—examples from
southern countries are smaller, and have their lighter
plumage of a clearer tint, than those from the north; hut
as regards bulk the Black Crow varies in like manner, and in
both the females are less than the males. The whole length
of either form is from eighteen and a half to twenty inches;
the wing, from the carpal joint to the tip, is from twelve to
fourteen inches ; the first primary is about three inches
shorter than the second, which is an inch shorter than the
third, and this is a little shorter than the fourth. The tail *
* The notion, however, has long prevailed in the mind or the imagination of
some of those best fitted to exercise either. As an example, the excellent
remarks on this subject of Mr. Hancock in his ‘ Birds of Northumberland and
Durham § (pp. 32-36) may especially be cited.
’t Instances more or less similar are found in the interbreeding of certain
“ species” of Himalayan Pheasants (Oallophasis—the Euplocamus of some
authors), of Boilers (Ooracias indicus and C. affinis) in India, and of the North-
American Woodpeckers of the genus Colaptes.
varies from seven to nearly eight inches and a half; the hill
measures a trifle more than half an inch in height and from
two to two inches and a quarter in length ; the tarsus from
a little over two to a little over two inches and a third.
In both forms the hill, legs and toes are black; hut in the
Grey Crow the claws are of a very dark horn-colour, while
in the Black Crow they are pure black: the irides are in
both of a dark greyish-hrowrn. In the Black Crow the
whole plumage is entirely black, glossed above with violet
and green reflexions according to the light in which it is
viewed. In the Grey Crow the nape, back, rump and lower
parts of the body (except the black feathers covering the
tibio-tarsal joint) are of a smoky-grey, the shafts of most of
the feathers being dark slaty-grey or black, while all the
rest of the plumage is precisely as in the Black Crow; but
the exact extent of grey varies in some degree, as also does
its shade, as before said.. In both forms the young are
distinguished by the want of lustre on their feathers..
Next as regards habits. If our view be limited by the
confines of the United Kingdom, two discrepancies are manifest.
First, that, while the Black Crow inhabits chiefly
more or less wooded country, the Grey Crow frequents moorland
tracts—both remarks referring to the breeding-season.
But directly we cross to Holland we find the Black Crow
nesting on the ground in open districts, while in Scandinavia
the Grey Crow frequents localities of the same kind as those
which the Black Crow affects with us. It seems not unreasonable,
knowing that many of our treeless moors were
once covered with forest, to suppose that when first occupied
by the ancestors of the Grey Crows which now possess those
places, they did not so much differ as at present from the
woodland haunts of the Norwegian and Swedish birds. The
Grey Crow readily adapts itself to circumstances. It builds
its nest equally on the storm-swept cliffs of Shetland and on
the palms of sunny Egypt. There is accordingly no wonder
in its retaining its seat in Scotland or Ireland, though the
trees which once sheltered its fore-fathers have long since
been laid low. •