PLANTIGRADE carnivora, general sterility of the, in captivity.
PLANTS, progress of cultivation of. -cultivated, their geographical derivation. -crossing of. -comparative fertility of wild and cultivated. -self-impotent. -dimorphic and trimorphic. -sterility of, from changed conditions. -from contabescence of anthers. -from monstrosities. -from doubling of the flowers. -from seedless fruit. -from excessive development of vegetative organs. -influence of selection on. -variation by selection, in useful parts of. -variability of. -variability of, induced by crossing. -direct action of change of climate on. -change of period of vegetation in. -varieties of, suitable to different climates. -correlated variability of. -antiquity of races of.
PLASTICITY, inheritance of.
PLATEAU, F., on the vision of amphibious animals.
Platessa flesus.
PLATO, notice of selection in breeding dogs by.
PLICA polonica.
PLINY, on the crossing of shepherd dogs with the wolf. -on Pyrrhus' breed of cattle. -on the estimation of pigeons among the Romans. -pears described by.
PLUM. -stones figured. -varieties of the. -bud-variation in the. -peculiar disease of the. -flower-buds of, destroyed by bullfinches. -purple-fruited, liable to certain diseases.
PLUMAGE, inherited peculiarities of, in pigeons. -sexual peculiarities of, in fowls.