variability of, induced by crossing, ii. [265];
direct action of change of climate on, ii. [277];
change of period of vegetation in, ii. [304]-[305];
varieties of, suitable to different climates, ii. [306];
correlated variability of, ii. [330]-[331];
antiquity of races of, ii. [429].
Plasticity, inheritance of, ii. [241].
Plateau, F., on the vision of amphibious animals, ii. [223].
Platessa flesus, ii. [53].
Plato, notice of selection in breeding dogs by, ii. [212].