The Power of Movement in Plants Page 01
POWER OF MOVEMENT
POWER OF MOVEMENT
BY CHARLES DARWIN, LL.D., F.R.S.
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
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
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
THE CIRCUMNUTATING MOVEMENTS OF THE SEVERAL PARTS OF MATURE PLANTS.
Circumnutation of stems: concluding remarks on--Circumnutation of stolons: 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.]
MODIFIED CIRCUMNUTATION: 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
MODIFIED CIRCUMNUTATION: SLEEP OR NYCTITROPIC MOVEMENTS, THEIR USE: SLEEP OF COTYLEDONS.
Preliminary sketch of the sleep or nyctitropic movements of leaves-- Presence of pulvini--The lessening of radiation the final cause of nyctitropic movements--Manner of trying experiments on leaves of Oxalis, Arachis, Cassia, Melilotus, Lotus and Marsilea and on the cotyledons of Mimosa--Concluding remarks on radiation from leaves--Small differences in the conditions make a great difference in the result - Description of the nyctitropic position and movements of the cotyledons of various plants-- List of species--Concluding remarks--Independence of the nyctitropic movements of the leaves and cotyledons of the same species--Reasons for believing that the movements have been acquired for a special purpose...280-316