260;
osteological characters of, i. 260-270;
effects of disuse of parts in, i. 270-274, ii. 298;
feral, i. 190, ii. 33;
polydactylism in, ii. 14;
fertility of, increased by domestication, ii. 112, 167;
sterility of, under certain conditions, ii. 162;
influence of selection on, ii. 196, 198, 209, 210;
evils of close interbreeding of, ii. 124-125;
crossing of, ii. 95, 96, 97;
prepotency of transmission in, ii. 67;
rudimentary organs in, ii. 315;
crossing of non-sitting varieties of, ii. 43-44;
homology of wing and leg feathers in, ii. 323;
hybrids of, with pheasants and _Gallus Sonneratii_, ii. 45;
black-skinned, ii. 209-210;
black, preyed upon by the osprey in Iceland, ii. 230;
five-toed, mentioned by Columella, ii. 429;
rumpless, tailed chickens produced by, ii. 31;
Dorking, crosses of, ii. 93;
form of comb and colour of plumage in, ii. 238;
game, crossing of white and black, ii. 92;
five-spurred, ii. 391;
Spanish, liable to suffer from frost, ii. 306;
Polish, peculiarities of skull of, ii. 332-333.
FOX, sterility of, in captivity, ii. 151.
FOX, S. Bevan, races of bees, i. 298.
FOX, W. Darwin, gestation of the dog, i. 30;
"Negro" cat, i. 46;
reversion of sheep in colour, ii. 30;
period of gestation in the pig, i. 74;
young of the Himalayan rabbit, i. 109;
crossing of wild and domestic turkeys, i. 292;
reversion in crossed musk ducks, ii. 40;
spontaneous segregation of varieties of geese, ii. 104;
effects of close interbreeding upon bloodhounds, ii. 121;
deafness of white cats with blue eyes, ii. 329.
FOXHOUNDS, i. 40, ii. 120.
_Fragaria chiloensis_, i. 351.
_Fragaria collina_, i. 351.
_Fragaria dioica_ of Duchesne, i. 353.
_Fragaria elatior_, i. 351.
_Fragaria grandiflora_, i. 351.
_Fragaria vesca_, i. 351.
_Fragaria virginiana_, i. 351.
_Fraxinus excelsior_, i. 360, 362, ii. 19.
_Fraxinus lentiscifolia_, ii. 19.
FRIESLAND cattle, probably descended from _Bos primigenius_, i. 81.
FRILLBACK (pigeon), i. 155;
Indian, i. 153.
_Fringilla ciris_, ii. 154.
_Fringilla spinus_, ii. 154.
FRIZZLED fowls, i. 230;
horses, i. 54.
FROG, polydactylism in the, ii. 14.
FRUIT, seedless, ii. 168.
FRUIT-TREES, varieties of, occurring wild, i. 310.
FRY, Mr., on fertile hybrid cats, i. 44;
on feral fowls in Ascension, i. 238.
FUCHSI