Pain, sense of, [170]-172.

Parents, advantage of two, [65]-66;

cases of one, [71]-73.

Parrots, [108]-109, [113].

Pigs, and rattlesnakes, [264];

teeth of, [325] and following.

Plants, as engines, [240]-241;

take food from air, [250], [254];

sickness of, [286] and following.

Rabbit, [12], [113], [341].