Siam, proportion of male and female births in.
Siamese, general beardlessness of the; notions of beauty of the; hairy family of.
Sidgwick, H., on morality in hypothetical bee community; our actions not entirely directed by pain and pleasure.
Siebold, C.T., von, on the proportion of sexes in the Apus; on the auditory apparatus of the stridulent Orthoptera.
Sight, inheritance of long and short.
Signal-cries of monkeys.
Silk-moth, proportion of the sexes in; Ailanthus, Prof. Canestrini, on the destruction of its larvae by wasps; difference of size of the male and female cocoons of the; pairing of the.
Simiadae, their origin and divisions.
Similarity, sexual.
Singing of the Cicadae and Fulgoridae; of tree-frogs; of birds, object of the.