CONTENTS. IS 



of light do not correspond with its intensity — Ettccts of previoui. 

 illumination — Time required for the action of light — After-effects 

 of light — Apogeotropism acts as soon as light fails — Accuracy 

 with which plants benfl to the light — This dependent on the 

 iUumination of one whole side of the part — Localised sensitive- 

 ness to light and its transmitted effects — Cotyledons of Phalaris, 

 manner of bending — Results of the exclusion of light from their 

 tiys — Effects transmitted beneath the surface of th'e ground — 

 Lateral illumination of the tip determines the direction of the 

 curvature of the base — Cotyledons of A vena, curvature of basal 

 part due to the illumination of upper part — Similar results with 

 the hypocotyls of Brassica and Beta — Radicles of Sinapis aphelio- 

 tropic,due to the sensitiveness of their tips — Concluding remarks 

 and summary of chapter — Means by which circumnutation hag 

 been converted into hel iotropism or apheliotropism Page 449-492 



CHAPTEE X. 



Modified Cikcumndtation : Movements excited by 

 Gravitation. 



Means of observation — Apogeotropism — Cytisus — Verbena — Beta 

 — Gradual conversion of tlie movement of circumnutation into 

 apogeotropism in Bubus, 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 — Trifolinm 

 subterraneura — Arachis — Amphicarpiea — Diageotropism — 

 Conclusion 493-522 



CHAPTEE XL 



Localised Bemsitiveness to Gravitation, and its Tbansmittbs 

 Effects. 



Greneral considerations — Vicia faba, effects of amputating the tips of 

 the radicles — Regeneration of the tips — Effects of a short ex- 

 posure of the tips to geotroi'ic action and their subsequent 

 amputation — Effects of amputating the tips obliquely — Effects 

 of cauterising the tij* — Effects of grease on the tips — Pisiun 



