Food, influence of, on the pig, i. 72;

on cattle, i. 91;

excess of, a cause of variability, ii. [257].

Forbes, D., on Chilian sheep, i. 95;

on the horses of Spain, Chili, and the Pampas, i. 52.

Formica rufa, ii. [251].

Fortune, R., sterility of the sweet potato in China, ii. [169];

development of axillary bulbs in the yam, ibid.

Fowl, common, breeds of, i. 225-230;

supposed plurality of origin, i. 230;