Dragon-flies, caudal appendages of male; relative size of the sexes of; difference in the sexes of; want of pugnacity by the male.
Drake, breeding plumage of the.
Dreams, possible source of the belief in spiritual agencies.
Drill, sexual difference of colour in the.
Dromaeus irroratus.
Dromolaea, Saharan species of.
Drongo shrike.
Drongos, racket-shaped feathers in the tails of.
Dryness of climate, supposed influence of, on the colour of the skin.
Dryopithecus.