Oleander, stock affected by grafting in the, i. 394.

Ollier, Dr., insertion of the periosteum of a dog beneath the skin of a rabbit, ii. [369].

Oncidium, reproduction of, ii. [133]-[135], [164].

Onions, crossing of, ii. [90];

white, liable to the attacks of fungi and disease, ii. [228], [336].

Ophrys apifera, self-fertilisation of, ii. [91];

formation of pollen by a petal in, ii. [392].

Opuntia leucotricha, ii. [277].

Orange, i. 334-336;

crossing of, ii. [91];