Frogs, male; temporary receptacles for ova possessed by; ready to breed before the females; fighting of; vocal organs of.
Frontal bone, persistence of the suture in.
Fruits, poisonous, avoided by animals.
Fuegians, difference of stature among the; power of sight in the; skill of, in stone-throwing; resistance of the, to their severe climate; mental capacity of the; quasi-religious sentiments of the; resemblance of, in mental characters, to Europeans; mode of life of the; aversion of, to hair on the face; said to admire European women.
Fulgoridae, songs of the.
Fur, whiteness of, in Arctic animals in winter.
Fur-bearing animals, acquired sagacity of.
Gallicrex, sexual difference in the colour of the irides in.
Gallicrex cristatus, pugnacity of male; red carbuncle occurring in the male during the breeding-season.
Gallinaceae, frequency of polygamous habits and of sexual differences in the; love-gestures of; decomposed feathers in; stripes of young; comparative sexual differences between the species of; plumage of.