Soldiers and sailors, difference in the proportions of.
Solenostoma, bright colours and marsupial sac of the females of.
Song, of male birds appreciated by their females; want of, in brilliant plumaged birds; of birds.
Sorex, odour of.
Sounds, admired alike by man and animals; produced by fishes; produced by male frogs and toads; instrumentally produced by birds.
Spain, decadence of.
Sparassus smaragdulus, difference of colour in the sexes of.
Sparrow, pugnacity of the male; acquisition of the Linnet’s song by a; coloration of the; immature plumage of the.
Sparrow, white-crowned, young of the.
Sparrows, house-and tree-.