CONTENTS 



PART I 



WATER PLANTS AS A BIOLOGICAL GROUP, WITH A CON- 

 SIDERATION OF CERTAIN TYPICAL LIFE-HISTORIES 



CHAP. PAGE 



I. Water Plants as a Biological Group ... 3 



(i) Introduction ...... 3 



(ii) Biological Classification of Hydrophytes . . 5 



II. The Life-history of the Alismaceae ... 9 



III. The Life-history of the Nymphaeaceae and of 



LiMNANTHEMUM ...... 24 



IV. The Life-history of Hydrocharis^ Stratiotes^ and 



OTHER Fresh-water Hydrocharitaceae . . 42 



V. The Life-history of the Potamogetonaceae of 



Fresh Waters ...... 58 



VI. The Life-history of the Lemnaceae and of P/st/a 73 



VII. The Life-history of Ceratophyllum ... 84 



VIII. The Life-history of the Aquatic Utricularias and 



OF Aldrovandia ...... 91 



IX. The Life-history of the Tristichaceae and 



PODOSTEMACEAE . . . . . .112 



X. The Life-history of the Marine Angiosperms . 123 



PART II 



THE VEGETATIVE AND REPRODUCTIVE ORGANS OF 

 WATER PLANTS, CONSIDERED GENERALLY 



XI. Leaf Types and Heterophylly in Aquatics . . 139 

 (i) Types of I^eaf in Water Plants . . . 1 39 



(ii) The Facts of Heterophylly under Natural 



Conditions . . . . . .143 



(iii) The Interpretation of Heterophylly . . 155 



XII. The Anatomy of Submerged Leaves . . .163 



XIII. The Morphology and Vascular Anatomy of 



Aquatic Stems . . . . . .172 



XIV. The Aerating System in the Tissues of Hydro- 



phytes . ..... 183 



