CHAPTER I. THE CIRCUMNUTATING MOVEMENTS OF SEEDLING PLANTS. Brassica oleracea, circumnutation of the radicle, of the arched hypocotyl whilst still buried beneath the ground, whilst rising above the ground and straightening itself, and when erect—Circumnutation of the cotyledons—Rate of movement—Analogous observations on various organs in species of Githago, Gossypium, Oxalis, Tropaeolum, Citrus, Aesculus, of several Leguminous and Cucurbitaceous genera, Opuntia, Helianthus, Primula, Cyclamen, Stapelia, Cerinthe, Nolana, Solanum, Beta, Ricinus, Quercus, Corylus, Pinus, Cycas, Canna, Allium, Asparagus, Phalaris, Zea, Avena, Nephrodium, and Selaginella...10-66 CHAPTER II. GENERAL CONSIDERATIONS ON THE MOVEMENTS AND GROWTH OF SEEDLING PLANTS. Generality of the circumnutating movement—Radicles, their circumnutation of service—Manner in which they penetrate the ground—Manner in which hypocotyls and other organs break through the ground by being arched—Singular manner of germination in Megarrhiza, etc.—Abortion of cotyledons- -Circumnutation of hypocotyls and epicotyls whilst still buried and arched- -Their power of straightening themselves—Bursting of the seed-coats—Inherited effect of the arching process in hypo- [page vi.] gean hypocotyls—Circumnutation of hypocotyls and epicotyls when erect—Circumnutation of cotyledons—Pulvini or joints of cotyledons, duration of their activity, rudimentary in Oxalis corniculata, their development—Sensitiveness of cotyledons to light and consequent disturbance of their periodic movements—Sensitiveness of cotyledons to contact...Page 67-128 CHAPTER III. SENSITIVENESS OF THE APEX OF THE RADICLE TO CONTACT AND TO OTHER IRRITANTS. Manner in which radicles bend when they encounter an obstacle in the soil—Vicia faba, tips of radicles highly sensitive to contact and other irritants—Effects of too high a temperature—Power of discriminating between objects attached on opposite sides—Tips of secondary radicles sensitive—Pisum, tips of radicles sensitive—Effects of such sensitiveness in overcoming geotropism—Secondary radicles—Phaseolus, tips of radicles hardly sensitive to contact, but highly sensitive to caustic and to the removal of a slice—Tropaeolum—Gossypium—Cucurbita—Raphanus—Aesculus, tip not sensitive to slight contact, highly sensitive to caustic—Quercus, tip highly sensitive to contact—Power of discrimination—Zea, tip highly sensitive, secondary radicles—Sensitiveness of radicles to moist air—Summary of chapter...129-200 CHAPTER IV. THE CIRCUMNUTATING MOVEMENTS OF THE SEVERAL PARTS OF MATURE PLANTS. Circumnutation of concluding remarks on—Circumnutation of aid thus afforded in winding amongst the stems of surrounding plants—Circumnutation of flower-stems—Circumnutation of Dicotyledonous leaves—Singular oscillatory movement of leaves of Dionaea—Leaves of Cannabis sink at night—Leaves of Gymnosperms—Of Monocotyledons—Cryptogams—Concluding remarks on the circumnutation of leaves; generally rise in the evening and sink in the morning...201-262 [page vii.] CHAPTER V. MODIFIED CLIMBING PLANTS; EPINASTIC AND HYPONASTIC MOVEMENTS. Circumnutation modified through innate causes or through the action of external conditions—Innate causes—Climbing plants; similarity of their movements with those of ordinary plants; increased amplitude; occasional points of difference—Epinastic growth of young leaves—Hyponastic growth of the hypocotyls and epicotyls of seedlings—Hooked tips of climbing and other plants due to modified circumnutation—Ampelopsis tricuspidata—Smithia Pfundii—Straightening of the tip due to hyponasty—Epinastic growth and circumnutation of the flower-peduncles of Trifolium repens and Oxalis carnosa...Page 263-279 CHAPTER VI. MODIFIED SLEEP OR NYCTITROPIC MOVEMENTS, THEIR SLEEP OF COTYLEDONS. Preliminary sketch of the sleep or nyctitropic movements of leaves—Presence o