Sparrows, new mates found by.

Sparrows, sexes and young of; learning to sing.

Spathura Underwoodi.

Spawning of fishes.

Spear, used before dispersion of man.

Species, causes of the advancement of; distinctive characters of; or races of man; sterility and fertility of, when crossed; supposed, of man; gradation of; difficulty of defining; representative, of birds; of birds, comparative differences between the sexes of distinct.

Spectrum femoratum, difference of colour in the sexes of.

Speech, connection between the brain and the faculty of; connection of intonation with music.

Spel, of the black-cock.

Spencer, Herbert, on the influence of food on the size of the jaws; on the dawn of intelligence; on the origin of the belief in spiritual agencies; on the origin of the moral sense; on music.