Haematoxylon Campechianum, nocturnal movement of leaves, 368, 369

Hedera helix, circumnutation of stem, 207

Hedysarum coronarium, nocturnal movements of leaves, 356

Helianthemum prostratum, geotropic movement of flower-heads, 518

Helianthus annuus, circumnutation of hypocotyl, 45 —­, arching of hypocotyl, 90 —­, nocturnal movement of cotyledons, 305

Heliotropism, 5; uses of, 449; a modified form of circumnutation, 490

Helleborus niger, mode of breaking through the ground, 86

Hensen, Prof., on roots in worm-burrows, 72

Henslow, Rev. G., on the cotyledons of Phalaris Canariensis, 62

Hofmeister, on the curious movement of Spirogyra, 3, 259, n.; of the leaves of Pistia stratiotes, 255; of cotyledons at night, 297; of petals, 414 —­ and Batalin on the movements of the cabbage, 229

Hooker, Sir J., on the effect of light on the pitchers of Sarracenia, 450

Hypocotyl, 5; manner of breaking through the ground, 77; emerges under the form of an arch, 553

Hypocotyls and Epicotyls, circumnutation and other movements when arched, 98; power of straightening themselves, 100; rupture of the seed-coats, 102-106; illustration of, 106; circumnutation when erect, 107; when in dark, 108

Hyponasty, 6, 267

I.
Iberis umbellata, movement of stem, 202.

Illumination, effect of, on the sleep of leaves, 398

Imatophyllum vel Clivia (sp.?), movement of leaves, 255

Indigofera tinctoria, leaflets depressed at night, 354

Inheritance in plants, 407, 491

Insectivorous and climbing plants not heliotropic, 450; influence of light on, 488

Ipomoea bona nox, arching of hypocotyl, 90 —­, nocturnal position of cotyledons, 306, 312 —­ coerulea vel Pharbitis nil, circumnutation of seedlings, 47 —­, movement of cotyledons, 47-49, 109 —­, nocturnal movements of cotyledons, 305 —­, sleep of leaves, 386 —­, sensitiveness to light, 451 —­, the hypocotyledonous stems heliotropic, 453 —­ coccinea, position of cotyledons at night, 306, 312 —­ leptophylla, mode of breaking through the ground, 83, 84 —­, arching of the petioles of the cotyledons, 90 —­, difference in sensitiveness to gravitation in different parts, 509 —­, extraordinary manner of germination, 557 [page 582]

IPOMOEA—­LOTUS

Ipomoea pandurata, manner of germination, 84, 557 —­ purpurea (vel Pharbitis hispida), nocturnal movement of cotyledons, 305, 312 —­, sleep of leaves, 386 —­, sensitiveness to light, 451 —­, the hypocotyledonous stems heliotropic, 453

Iris pseudo-acorus, circumnutation of leaves, 253

Irmisch, on cotyledons of Ranunculus Ficaria, 96

Ivy, its stems heliotropic, 451

K.

Kerner on the bending down of peduncles, 414

Klinostat, the, an instrument devised by Sachs to eliminate geotropism, 93