readily produced in captivity, ii. [151].

Hybridisation, singular effects of, in oranges, i. 336;

of cherries, i. 347;

difficulty of, in Cucurbitæ, i. 358;

of roses, i. 366.

Hybridism, ii. [178]-[191];

the cause of a tendency to double flowers, ii. [171];

in relation to pangenesis, ii. [385].

Hybridity in cats, i. 44-45;

supposed of peach and nectarine, i. 342.