sistency of leaves of, i. 363;
valueless as timber at the Cape of Good Hope, ii. 274;
changes in, dependent on age, i. 387;
galls of the, ii. 282.
OATS, wild, i. 313;
in the Swiss lake-dwellings, i. 319.
OBERLIN, change of soil beneficial to the potato, ii. 146.
ODART, Count, varieties of the vine, i. 333, ii. 278;
bud-variation in the vine, i. 375.
ODOUR and colour, correlation of, ii. 325.
_Oecidium_, ii. 284.
_Oenothera biennis_, bud-variation in, i. 382.
OGLE, W., resemblance of twins, ii. 252.
OIL-GLAND, absence of, in fantail pigeons, i. 147, 160.
OLDFIELD, Mr., estimation of European dogs among the natives of
Australia, ii. 215.
OLEANDER, stock affected by grafting in the, i. 394.
OLLIER, Dr., insertion of the periosteum of a dog beneath the skin of a
rabbit, ii. 369.
_Oncidium_, reproduction of, ii. 133-135, 164.
ONIONS, crossing of, ii. 90;
white, liable to the attacks of fungi and disease, ii. 228, 336.
_Ophrys apifera_, self-fertilisation of, ii. 91;
formation of pollen by a petal in, ii. 392.
_Opuntia leucotricha_, ii. 277.
ORANGE, i. 334-336;
crossing of, ii. 91;
with the lemon, i. 399, ii. 365;
naturalisation of, in Italy, ii. 308;
variation of, in North Italy, ii. 256;
peculiar variety of, ii. 331;
Bizzaria, i. 391;
trifacial, _ibid._
ORCHIDS, reproduction of, i. 402, 403; ii. 133-135.
ORFORD, Lord, crossing greyhounds with the bulldog, i. 41.
ORGANISMS, origin of, i. 13.
ORGANISATION, advancement in, i. 8.
ORGANS, rudimentary and aborted, ii. 315-318;
multiplication of abnormal, ii. 391.
ORIOLE, assumption of hen-plumage by a male in confinement, ii. 158.
ORKNEY islands, pigs of, i. 70;
pigeons of, i. 184.
ORTHOPTERA, regeneration of hind legs in the, ii. 294.
_Orthosia munda_, ii. 157.
ORTON, R., on the effects of cross-breeding on the female, i. 404;
on the Manx cat, ii. 66;
on mongrels from the silk-fowl, ii. 67.
OSBORNE, Dr., inherited mottling of the iris, ii. 10.
OSPREY, preying on Black-fowls, ii. 230.
OSTEN-SACKEN, Baron, on American oak galls, ii. 282.
OSTEOLOGICAL characters of pigs, i. 66, 67, 71-74;
of rabbits, i. 115-130;
of pigeons, i. 162-167;
of ducks, i. 282-284.
OSTRICH, diminished fertility of the, in captivity, ii. 156.
OSTYAKS, selection of dogs by the, ii. 206.
OTTER, ii. 151.
"OTTER" sheep of Massachu