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—Arac
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
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