Mirabilis jalapa and longiflora, nocturnal movements of cotyledons, 307 —­, nyctitropic movement of leaves, 387

Mohl, on heliotropism in tendrils, stems, and twining plants, 451

Momentum-like movement, the accumulated effects of apogeotropism, 508

Monocotyledons, sleep of leaves, 389

Monotropa hypopitys, mode of breaking through the ground, 86

Morren, on the movements of stamens of Sparmannia and Cereus, 226

Müller, Fritz, on Cassia tora, 34; on the circumnutation of Linum usitatissimum, 203; movements of the flower-stems of an Alisma, 226

Mutisia clematis, movement of leaves, 246
—­, leaves not heliotropic, 451

N.

Natural selection in connection with geotropism, heliotropism, etc., 570

Nephrodium molle, circumnutation of very young frond, 66 —­, of older frond, 257 —­, slight movement of fronds, 509

Neptunia oleracea, sensitiveness to contact, 128 —­, nyctitropic movement of leaflets, 374 —­, of pinnae, 402 [page 585]

NICOTIANA—­OXALIS

Nicotiana glauca, sleep of leaves, 385, 386
—­, circumnutation of leaves, 386

Nobbe, on the rupture of the seed-coats in a seedling of Martynia, 105

Nolana prostrata, movement of seedlings in the dark, 50
—­, circumnutation of seedling, 108

Nyctitropic movement of leaves, 560

Nyctitropism, or sleep of leaves, 281; in connection with radiation, 286; object gained by it, 413

O.

Observation, methods of, 6

Oenothera mollissima, sleep of leaves, 383

Opuntia basilaris, conjoint circumnutation of hypocotyl and cotyledon, 44 —­, thickening of the hypocotyl, 96 —­, circumnutation of hypocotyl when erect, 107 —­, burying of, 109

Orange, seedling, circumnutation of, 510

Orchis pyramidalis, complex movement of pollinia, 489

Oxalis acetosella, circumnutation of flower-stem, 224 —­, effects of exposure to radiation at night, 287, 288, 296 —­, circumnutation and nyctitropic movement in full-grown leaf, 326 —­, circumnutation of leaflet when asleep, 327 —­, rate of circumnutation of leaflets, 404 —­, effect of sunshine on leaflets, 447 —­, circumnutation of peduncle, 506 Oxalis acetosella, seed-capsules, only occasionally buried, 518 —­ articulata, nocturnal movements of cotyledons, 307 —­ (Biophytum) sensitiva, rapidity of movement of cotyledons during the day, 26 —­, pulvinus of, 113 —­, cotyledons vertical at night, 116, 118 —­ bupleurifolia, circumnutation of foliaceous petiole, 328 —­, nyctitropic movement of terminal leaflet, 329 —­ carnosa, circumnutation of flower-stem, 223 —­, epinastic movements of flower-stem, 504 —­, effect of exposure at night, 288, 296 —­, movements of the flower-peduncles due to apogeotropism and other forces, 503-506 —­ corniculata (var. cuprea),