Honey-dew.

Hooker, Dr., Euryale ferox and Victoria regia, each producing several flowers at once. on sexual relation of trees in New Zealand.

Horse-chestnut.

Humble-bees, see Bees.

Humboldt, on the grains of cereals.

Humming-Birds a means of cross-fertilisation.

Hyacinth.

Hybrid plants, tendency to revert to their parent forms.

Hypecoum grandiflorum.
—­ procumbens.

Iberis umbellata (var. kermesiana). measurement. cross by fresh stocks. remarks on experiments. superiority of crossed over self-fertilised seedlings. early flowering. number of seeds. highly self-fertile. prepotency of other pollen. —­ amara.

Impatiens frequented by humming-birds. —­ barbigera. —­ fulva. —­ noli-me-tangere. —­ pallida.

Inheritance, force of, in plants.

Insects, means of cross-fertilisation. attracted by bright colours. by odours. by conspicuous flowers. dark streaks and marks as guides for. flowers adapted to certain kinds.

Ipomoea purpurea. measurements. flowers on same plant crossed. cross with fresh stock. descendants of Hero. summary of measurements. diagram showing mean heights. summary of observations. of experiments. superiority of crossed. early flowering. effects of intercrossing. uniform colour of self-fertilised. seeds. highly self-fertile. prepotency of other pollen.

Iris, secretion of saccharine matter from calyx.

Isotoma.

Juglans regia.

Kalmia latifolia.

Kerner, on protection of the pollen. on the single daily flower of Villarsia parnassifolia. pollen carried by wind.

Kidney-bean.

Kitchener, Mr., on the action of the stigma.
on Viola tricolor.

Knight, A., on the sexual intercourse of plants. crossing varieties of peas. sexual reproduction.

Kohl-rabi, prepotency of pollen.

Kolreuter on cross-fertilisation.
number of pollen-grains necessary for fertilisation.
sexual affinities of Nicotiana. 
Verbascum phoeniceum.
experiments with pollen of Hibiscus vesicarius.

Kuhn adopts the term cleistogene.

Kurr, on excretion of nectar.
removal of corolla.

Labiatae.

Lactuca sativa. measurement. prepotency of other pollen.

Lamium album.
—­ purpureum.

Lathyrus odoratus. measurements. remarks on experiments. period of flowering. cross-fertilisation. seeds. self-fertile. —­ grandiflorus. —­ nissolia. —­ sylvestris, perforation of corolla.

Lawes and Gilbert, Messrs., consumption of inorganic matter by plants.

Laxton, Mr., crossing varieties of peas.

Lecoq, Cyclamen repandum. on Fumariaceae. annual plants rarely dioecious.

Leersia oryzoides.

Leguminosae.
summary on the.

Leighton, Reverend W.A., on Phaseolus multiflorus. 
Acacia magnifica.