Illustration: CROWNED PIGEON, _Goura coronata_ (After Mme. Knip, as
above.)]

[Illustration: NICOBAR PIGEON, _Caloenas nicobarica_. (After Mme. Knip,
as above.)]

[Illustration: Photographs of two typical pedigree Homing or Racing
Pigeons, colours black and blue chequer, bred and shown by Frederick
Romer, Esq., prize-winners in races from France to England.]

The stock-dove (_C. aenas_ of most authors) is a smaller species, with
many of the habits of the former, but breeding by preference in the
stocks of hollow trees or in rabbit-holes. It is darker in colour than
the ring-dove, without any white on its neck or wings, and is much less
common and more locally distributed.

The rock-dove (_C. livia_, Temm.) much resembles the stock-dove, but is
of a lighter colour, with two black bars on its wings, and a white rump.
In its wild state it haunts most of the rocky parts of the coast of
Europe, from the Faeroes to the Cyclades, and, seldom going inland, is
comparatively rare. Yet, as it is without contradiction the parent-stem
of all British domestic pigeons, its numbers must far exceed those of
both the former put together. In Egypt and various parts of Asia it is
represented by what Charles Darwin has called "wild races," which are
commonly accounted good "species" (_C. schimperi_, _C. affinis_, _C.
intermedia_, _C. leuconota_, and so forth), though they differ from one
another far less than do nearly all the domestic forms, of which more
than 150 kinds that "breed true," and have been separately named, are
known to exist. Very many of these, if found wild, would have
unquestionably been ranked by the best ornithologists as distinct
"species" and several of them would as undoubtedly have been placed in
different genera. These various breeds are classified by Darwin[1] in
_four_ groups as follows:--

GROUP I., composed of a _single_ Race, that of the "Pouters," having
the gullet of great size, barely separated from the crop, and often
inflated, the body and legs elongated, and a moderate bill. The most
strongly marked sub-race, the _Improved English Pouter_, is considered
to be the most distinct of all domesticated pigeons.

GROUP II. includes _three_ Races:--(1) "Carriers," with a long pointed
bill, the eyes surrounded by much bare skin, and the neck and body
much elongated; (2) "Runts," with a long, massive bill, and the body
of great size; and (3) "Barbs," with a short, broad bill, much bare