of Tropæolum majus and minus, i. 392;
variability of hybrids, ii. [265];
variable hybrids from one variable parent, ii. [270];
graft hybrid produced by inosculation in the vine, i. 395;
effect produced by grafts on the stock, i. 394, ii. [278];
tendency of hybrid plants to produce double flowers, ii. [171];
production of perfect fruit by sterile hybrids, ii. [172];
sexual elective affinity, ii. [180];
self-impotence in Lobelia, Verbascum, Lilium, and Passiflora, ii. [136]-[137];
on the action of pollen, ii. [108];