CONTENTS 



CHAP. 



XV. 



PAGE 



204 



210 



227 



Land Forms of Water Plants, and the Effect 

 OF Water upon Land Plants . 

 XVL The Roots of Water Plants 



XVIL The Vegetative Reproduction and Wintering 

 of Water Plants ..... 



XVI n. The Flowers of Water Plants and their Rela- 

 tion TO the Environment 



XIX. The Fruits, Seeds and Seedlings of Water 



Plants ........ 239 



PART III 



THE PHYSIOLOGICAL CONDITIONS OF PLANT LIFE 



IN WATER 

 XX. Gaseous Exchange in Water Plants . . 253 



XXI. Absorption of Water and Transpiration 



Current in Hydrophytes .... 260 



XXII. The Influence of certain Physical Factors in 



THE Life of Water Plants . . . 273 

 XXIII. The Ecology of Water Plants . . . 285 



PART IV 



THE STUDY OF WATER PLANTS FROM THE PHYLOGENETIC 

 AND EVOLUTIONARY STANDPOINTS 



The Dispersal and Geographical Distribution 

 OF Water Plants ..... 



The Affinities of Water Plants and their 

 Systematic Distribution among the Angio- 

 SPERMS ....... 



(i) The Affinities of Certain Aquatic Angio- 

 sperms ..... 



(ii) Theoretical Considerations . 



The Theory of the Aquatic Origin of Mono- 

 cotyledons ...... 



Water Plants and the Theory of Natural 

 Selection, with Special Reference to the 

 podostemaceae ..... 



Water Plants and the 'Law of Loss 

 Evolution ..... 



XXIV. 

 XXV. 



XXVI. 



xxvn. 



XXVIII. 



295 



308 



308 

 317 



322 



IN 



327 

 336 



Bibliography 



Index to Bibliography 



Index . 



349 



415 

 422 



