i. 77-78.
SMITH, Sir J. E., production of nectarines and peaches by the same tree,
i. 340;
on _Viola amoena_, i. 368;
sterility of _Vinca minor_ in England, ii. 170.
SMITH, J., development of the ovary in _Bonatea speciosa_, by irritation
of the stigma, i. 403.
SMITH, N. H., influence of the bull "Favourite" on the breed of
Short-horn cattle, ii. 65.
SMITH, W., on the inter-crossing of strawberries, i. 352.
SNAKE-RAT, ii. 87, 88.
SNAKES, form of the viscera in, ii. 344.
SNAPDRAGON, bud-variation in, i. 381;
non-inheritance of colour in, ii. 21;
peloric, crossed with the normal form, ii. 70, 93;
asymmetrical variation of the, ii. 322.
SOIL, adaptation of plums to, i. 346;
influence of, on the zones of pelargoniums, i. 366;
on roses, i. 367;
on the variegation of leaves, i. 383;
advantages of change of, ii. 146-148.
SOIL and climate, effects of, on strawberries, i. 353.
_Solanum_, non-intercrossing of species of, ii. 91.
_Solanum tuberosum_, i. 330-331.
SOLID-HOOFED pigs, i. 75.
SOLOMON, his stud of horses, i. 55.
SOMERVILLE, Lord, on the fleece of Merino sheep, i. 99;
on crossing sheep, ii. 120;
on selection of sheep, ii. 195;
diminished fertility of Merino sheep brought from Spain, ii. 161.
SOOTY fowls, i. 230, 256.
SOTO, Ferdinand de, on the cultivation of native plants in Florida, i.
312.
_Sorghum_, i. 371.
SPAIN, hawthorn monogynous in, i. 364.
SPALLANZANI, on feral rabbits in Lipari, i. 113;
experiments on salamanders, ii. 15, 293, 385;
experiments in feeding a pigeon with meat, ii. 304.
SPANIELS, in India, i. 38;
King Charles's, i. 41;
degeneration of, caused by interbreeding, ii. 121.
SPANISH fowls, i. 227, 250, 253;
figured, i. 226;
early development of sexual characters in, i. 250, 251;
furcula of, figured, i. 268.
SPECIES, difficulty of distinguishing from varieties, i. 4;
conversion of varieties into, i. 5;
origin of, by natural selection, ii. 414-415;
by mutual sterility of varieties, ii. 185-189.
{479}
SPENCER, Lord, on selection in breeding, ii. 195.
SPENCER, Herbert, on the "survival of the fittest," i. 6;
increase of fertility by domestication, ii. 111;
on life, ii. 148, 177;
changes produced by external conditions, ii. 281;
effects of use on organs, ii. 295, 296;
ascent of the sap in trees, ii. 296;
co