non-diffusion of cell-gemmules in, ii. [379].
Ferrets, ii. [111], [151], [206].
Fertilisation, artificial, of the St. Valery apple, i. 350.
Fertility, various degrees of, in sheep, i. 97;
unlimited mutual, of breeds of pigeons, i. 192-194;
comparative of mongrels and hybrids, ii. [100]-[101], [178]-[180];
influence of nourishment on, ii. [111];
diminished by close interbreeding, ii. [118], [175];
reduced, of Chillingham wild cattle, ii. [119];
of domesticated varieties when crossed, ii. [189].