PROCEEDINGS I NOV211921 



OF ^<J[ce Liwa^y, 



THE ROYAL SOCIETY. 

 Series B. Vol. 92. No. B 647. 



BIOLOGICAL SCIENCES. 



CONTENTS. 



Page 



The Development of Vegetation in the English Lakes, considered in relation 

 to the General Evolution of Glacial Lakes and Rock Basins. By 

 W. H. PEARSALL . . . . . . . . . . 259 



A Method for Investigating the Haemolytic Activity of Chemical Substances. 



By E. PONDER . . . . 285 



Observations on the Effects of Fat Excess on the Growth and Metamorphosis 



of Tadpoles. By R. McCARRlSON, M.D., D.Sc. LL.D,, Lt.-Col. I. M.S. 295 



Experimental Researches on Vegetable Assimilation and Respiration. 

 XIV. — Assimilation by Submerged Plants in Dilute Solutions of 

 Bicarbonates and of Acids : an Improved Bubble-Counting Technique. 

 By A. J. WILMOTT . .... . . . . . 304 



PRINTED AND PUBLISHED FOR THE ROYAL SOCIETY BY 

 HARRISON & SONS, Ltd., 44—47, ST. MARTIN'S LANE. LONDON, W.C.2. 



Price Fott-r Shillings. 



No. B 647. 



November 1 , 1921. 



