The Power of Movement in Plants | Page 2

of Genera and Families, which include sleeping plants--Description of the movements in the several Genera--Oxalis: leaflets folded at [page viii.] night--Averrhoa: rapid movements of the leaflets--Porlieria: leaflets close when plant kept very dry--Tropaeolum: leaves do not sleep unless well illuminated during day--Lupinus: various modes of sleeping--Melilotus: singular movements of terminal leaflet--Trifolium--Desmodium: rudimentary lateral leaflets, movements of, not developed on young plants, state of their pulvini--Cassia: complex movements of the leaflets--Bauhinia: leaves folded at night--Mimosa pudica: compounded movements of leaves, effect of darkness--Mimosa albida, reduced leaflets of--Schrankia: downward movement of the pinnae--Marsilea: the only cryptogam known to sleep--Concluding remarks and summary--Nyctitropism consists of modified circumnutation, regulated by the alternations of light and darkness--Shape of first true leaves...Page 317-417
CHAPTER VIII.
MODIFIED CIRCUMNUTATION: MOVEMENTS EXCITED BY LIGHT.
Distinction between heliotropism and the effects of light on the periodicity of the movements of leaves--Heliotropic movements of Beta, Solanum, Zea, and Avena--Heliotropic movements towards an obscure light in Apios, Brassica, Phalaris, Tropaeolum, and Cassia--Apheliotropic movements of tendrils of Bignonia--Of flower-peduncles of Cyclamen--Burying of the pods--Heliotropism and apheliotropism modified forms of circumnutation-- Steps by which one movement is converted into the other-- Transversal-heliotropismus or diaheliotropism influenced by epinasty, the weight of the part and apogeotropism--Apogeotropism overcome during the middle of the day by diaheliotropism--Effects of the weight of the blades of cotyledons--So called diurnal sleep--Chlorophyll injured by intense light--Movements to avoid intense light...418-448
CHAPTER IX.
SENSITIVENESS OF PLANTS TO LIGHT: ITS TRANSMITTED EFFECTS.
Uses of heliotropism--Insectivorous and climbing plants not heliotropic-- Same organ heliotropic at one age and not at another--Extraordinary sensitiveness of some plants to light--The effects [page ix.] of light do not correspond with its intensity--Effects of previous illumination--Time required for the action of light--After-effects of light--Apogeotropism acts as soon as light fails--Accuracy with which plants bend to the light--This dependent on the illumination of one whole side of the part--Localised sensitiveness to light and its transmitted effects--Cotyledons of Phalaris, manner of bending--Results of the exclusion of light from their tips--Effects transmitted beneath the surface of the ground--Lateral illumination of the tip determines the direction of the curvature of the base--Cotyledons of Avena, curvature of basal part due to the illumination of upper part--Similar results with the hypocotyls of Brassica and Beta--Radicles of Sinapis apheliotropic, due to the sensitiveness of their tips--Concluding remarks and summary of chapter-- Means by which circumnutation has been converted into heliotropism or apheliotropism...Page 449-492
CHAPTER X.
MODIFIED CIRCUMNUTATION: MOVEMENTS EXCITED BY GRAVITATION.
Means of observation--Apogeotropism--Cytisus--Verbena--Beta--Gradual conversion of the movement of circumnutation into apogeotropism in Rubus, Lilium, Phalaris, Avena, and Brassica--Apogeotropism retarded by heliotropism--Effected by the aid of joints or pulvini--Movements of flower-peduncles of Oxalis--General remarks on apogeotropism--Geotropism-- Movements of radicles--Burying of seed-capsules--Use of process--Trifolium subterraneum--Arachis--Amphicarpaea--Diageotropism--Conclusion...493-522
CHAPTER XI.
LOCALISED SENSITIVENESS TO GRAVITATION, AND ITS TRANSMITTED EFFECTS.
General considerations--Vicia faba, effects of amputating the tips of the radicles--Regeneration of the tips--Effects of a short exposure of the tips to geotropic action and their subsequent amputation--Effects of amputating the tips obliquely--Effects of cauterising the tips--Effects of grease on the tips--Pisum [page x.] sativum, tips of radicles cauterised transversely, and on their upper and lower sides--Phaseolus, cauterisation and grease on the tips--Gossypium-- Cucurbita, tips cauterised transversely, and on their upper and lower sides--Zea, tips cauterised--Concluding remarks and summary of chapter-- Advantages of the sensibility to geotropism being localised in the tips of the radicles...Page 523-545
CHAPTER XII.
SUMMARY AND CONCLUDING REMARKS.
Nature of the circumnutating movement--History of a germinating seed--The radicle first protrudes and circumnutates--Its tip highly sensitive-- Emergence of the hypocotyl or of the epicotyl from the ground under the form of an arch--Its circumnutation and that of the cotyledons--The seedling throws up a leaf-bearing stem--The circumnutation of all the parts or organs--Modified circumnutation--Epinasty and hyponasty--Movements of climbing plants--Nyctitropic movements--Movements excited by light and gravitation--Localised sensitiveness--Resemblance between the movements of plants and animals--The tip of the radicle acts like a brain...546-573
INDEX...574-593
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THE MOVEMENTS OF PLANTS.

INTRODUCTION.
THE chief object of the present work is to describe and connect together several large classes of movement, common to almost all plants. The most widely prevalent movement is essentially of the same nature as that of the stem of a climbing plant, which bends successively to all points of the compass, so that the tip revolves. This movement has been called by Sachs "revolving nutation;" but we have found it much more convenient to use the terms circumnutation and circumnutate. As we shall have to say much about this movement, it will be useful here briefly to describe its nature. If we observe a circumnutating stem, which happens at the time to be bent, we will say towards the north, it will be found gradually to bend more and more easterly, until it faces the east; and so onwards to the south, then to the west, and back again to the north. If the movement had been quite regular, the apex would have described a circle, or rather, as the stem