CONTENTS 



CHAPTER I 



INTRODUCTION 



Method of chemical analysis in photosynthetic investigation — 

 Difficulties of the problem arising from complicating factors — 

 The method of evolution of oxygen by water-plants — Errors 

 of the Bubble-counting Method — New method for securing high 

 accuracy in quantitative determinations — Different lines of 

 investigation on photosynthesis by the new method . 



CHAPTER II 



THE EVOLUTION OF PURE OXYGEN UNDER LIGHT 



The aquatic plant Hydrilla verticillata — Anatomical characteristics — 

 Analysis of pond-water — Proportions of different gases absorbed 

 by water — Method of obtaining evolution of unmixed oxygen — 

 Absorption of oxygen by water ...... 7 



CHAPTER III 



DETERMINATION OF RATE OF EVOLUTION OF EQUAL 

 VOLUMES OF OXYGEN 



Frequency and volume of the bubblets — Effects of depth of immer- 

 sion — Effect of choking of the cut end by mucilage — Spontane- 

 ous variation in the frequency of the bubblets — Determination 

 of successive evolution of equal volumes of oxygen — The plant- 

 vessel — The Bubbler — Measurement of photosynthetic activity — 

 Determination of the constant of the Bubbler .... 14 



30081 



