on horn-like processes in horses, i. 50.
Perdix rubra, occasional fertility of, in captivity, ii. [156].
Period of action of causes of variability, ii. [269].
Periosteum of a dog, producing bone in a rabbit, ii. [369].
Periwinkle, sterility of, in England, ii. [170].
Persia, estimation of pigeons in, i. 205;
carrier pigeon of, i. 141;
tumbler pigeon of, i. 150;
cats of, i. 45-47;
sheep of, i. 94.