i. 353;

on the stridulation of the _Acridiidae_, i. 356; on a Devonian insect, i. 360; on stridulation, ii. 331.

SCULPTURE, expression of the ideal of beauty by, ii. 350.

SEA-ANEMONIES, bright colours of, i. 322.

SEA-BEAR, polygamous, i. 268.

SEA-ELEPHANT, male, structure of the nose of the, ii. 278; polygamous, i. 268.

SEA-LION, polygamous, i. 268.

SEAL, bladder-nose, ii. 278.

SEALS, their sentinels generally females, i. 74; evidence furnished by, on classification, i. 190; sexual differences in the coloration of, ii. 287; appreciation of music by, ii. 333; battles of male, ii. 240; canine teeth of male, ii. 241; polygamous habits of, i. 268; pairing of, ii. 269; sexual peculiarities of, ii. 277.

SEA-SCORPION, sexual differences in, ii. 9.

SEASON, changes of colour in birds, in accordance with the, ii. 80; changes of plumage of birds in relation to, ii. 180.

SEASONS, inheritance at corresponding, i. 282.

SEBITUANI, ii. 340.

SEBRIGHT Bantam, i. 294.

SECONDARY sexual characters, i. 253; relations of polygamy to, i. 266; gradation of, in birds, ii. 135; transmitted through both sexes, i. 279.

SEDGWICK, W., on hereditary tendency to produce twins, i. 133.

SEEMANN, Dr., on the different appreciation of music by different peoples, ii. 334; on the effects of music, ii. 335.

_Selasphorus platycercus_, acuminate first primary of the male, ii. 65.

SELBY, P. J., on the habits of the black and red grouse, i. 269.

SELECTION, double, i. 276.

SELECTION of male by female birds, ii. 99, 122.

SELECTION, methodical, of Prussian grenadiers, i. 112.

SELECTION, sexual, influence of, on the colouring of Lepidoptera,