-INHERITANCE OF CHARACTERS--IMPERFECT
WINGS--LOST INSTINCTS--CORRELATED CHARACTERS.

I will, as in previous cases, first briefly describe the chief domestic
breeds of the duck:--

BREED 1. _Common Domestic Duck_.--Varies much in colour and in
proportions, and differs in instincts and disposition from the
wild-duck. There are several sub-breeds:--(1) The Aylesbury, of great
size, white, with pale-yellow beak and legs; abdominal sack largely
developed. (2) The Rouen, of great size, coloured like the wild-duck,
with green or mottled beak; abdominal sack largely developed. (3)
Tufted Duck, with a large top-knot of fine downy feathers, supported on
a fleshy mass, with the skull perforated beneath. The top-knot in a
duck which I imported from Holland was two and a half inches in
diameter. (4) Labrador (or Canadian, or Buenos Ayres, or East Indian);
plumage entirely black; beak broader, relatively to its length, than in
the wild-duck; eggs slightly tinted with black. This sub-breed perhaps
ought to be ranked as a breed; it includes two sub-varieties, one as
large as the common domestic duck, which I have kept alive, and the
other smaller and often capable of flight.[436] I presume it is this
latter sub-variety which has been described in France[437] as flying
well, being rather wild, and when cooked having the flavour of the
wild-duck; nevertheless this sub-variety is polygamous, like other
domesticated ducks and unlike the wild duck. These black Labrador ducks
breed true; {277} but a case is given by Dr. Turral of the French
sub-variety producing young with some white feathers on the head and
neck, and with an ochre-coloured patch on the breast.

BREED 2. _Hook-billed Duck_.--This bird presents an extraordinary
appearance from the downward curvature of the beak. The head is often
tufted. The common colour is white, but some are coloured like
wild-ducks. It is an ancient breed, having been noticed in 1676.[438]
It shows its prolonged domestication by almost incessantly laying eggs,
like the fowls which are called everlasting layers.[439]

BREED 3. _Call-Duck_.--Remarkable from its small size, and from the
extraordinary loquacity of the female. Beak short. These birds are
either white, or coloured like the wild-duck.

BREED 4. _Penguin Duck_.--This is the most remarkable of all the
breeds,