wild, difficulty of rearing, ii. 233;
effects of domestication on, ii. 278.
DUCKS, breeds of, i. 276-277;
origin of, i. 277;
history of, _ibid._;
wild, easily tamed, i. 278-279;
fertility of breeds of, when crossed, i. 279;
with the plumage of _Anas boschas_, i. 280;
Malayan penguin, identical in plumage with English, i. 280;
characters of the breeds of, i. 281-284;
eggs of, i. 281;
effects of use and disuse in, i. 284-286, ii. 298;
feral, in Norfolk, i. 190;
Aylesbury, inheritance of early hatching by, ii. 25;
reversion in, produced by crossing, ii. 40;
wildness of half-bred wild, ii. 45;
hybrids of, with the musk duck, ii. 45-46;
assumption of male plumage by, ii. 51;
crossing of Labrador and penguin, ii. 97;
increased fertility of, by domestication, ii. 112;
general fertility of, in confinement, ii. 157;
increase of size of, by care in breeding, ii. 199;
change produced by domestication in, ii. 262.
DUMERIL, Aug., breeding of _Siredon_ in the branchiferous stage, ii. 384.
DUN-coloured horses, origin of, i. 59.
DUREAU de la Malle, feral pigs in Louisiana, ii. 33;
feral fowls in Africa, _ibid._;
bud-variation in the pear, i. 376;
production of mules among the Romans, ii. 110.
_Dusicyon sylvestris_, i. 23.
DUTCH rabbit, i. 107.
DUTCH roller pigeon, i. 151.
DUTROCHET, pelorism in the laburnum, ii. 346.
DUVAL, growth of pears in woods in France, ii. 260.
DUVAL-Jouve, on _Leersia oryzoides_, ii. 91.
DUVERNOY, self-impotence in _Lilium candidum_, ii. 137.
DZIERZON, variability in the characters and habits of bees, i. 298.

EARLE, Dr., on colour-blindness, ii. 72, 328.
EARS, of fancy rabbits, i. 106;
deficiency of, in breeds of rabbits, i. 108;
rudimentary, in Chinese sheep, ii. 315;
drooping, ii. 301;
fusion of, ii. 341.
EATON, J. M., on fancy pigeons, i. 148, 153;
variability of characters in breeds of pigeons, i. 161;
reversion of crossed pigeons to coloration of _Columba livia_, i. 198;
on pigeon-fancying, i. 206, 215-216;
on tumbler-pigeons, i. 209, ii. 242;
carrier-pigeon, i. 211;
effects of interbreeding on pigeons, ii. 126;
properties of pigeons, ii. 197-198;
death of short-faced tumblers in the egg, ii. 226;
{449}
Archangel pigeon, ii. 240.
ECHINODERMATA, metagenesis in, ii. 367.
_Ectopistes_, specific difference in