PROCEEDINGS 



OF 



THE ROYAL SOCIETY. 



Series B. Vol. 84. No. B 569. 



BIOLOGICAL SCIENCES. 



CONTENTS. 



Page 



The Properties of Colloidal Systems. — II. On Adsorption as Preliminary 

 to Chemical Reaction. By W. M. BAYLISS, F.R.S., Institute of Physiology, 

 University College, London . ........ 81 



On the Distribution and Action of Soluble Substances in Frogs Deprived of 



their Circulatory Apparatus. By S. J. MELTZER, New York . . 9& 



The Mechanism of Carbon Assimilation : Part III. By FRANCIS L. USHER 



and J. H. PRIESTLEY 101 



Transmission of Amakebe by means of Rhipicephalus appendiculatus, the 



Brown Tick. By Dr. A. THEILER, C.M.G., Pretoria . . . .112 



The Discrimination of Colour. By F. W. EDRIDGE-GREEN, M.D., F.R.C.S., 



Beit Medical Research Fellow "6 



Note on the Sensibility of the Eye to Variations of Wave-length. By 



W. WATSON, D.Sc, F.R.S • • 8 



On the Direct Guaiacum Reaction given by Plant Extracts. By Miss 



M. WHELDALE, Fellow of Newnham College, Cambridge . . .121 



The Action of Radium Radiations upon some of the Main Constituents of 

 Normal Blood. By HELEN CHAMBERS, M.D., and S. RUSS, D.Sc, Beit 

 Memorial Research Fellow I2 + 



On a New Method of Estimating the Aperture of Stomata. By FRANCIS 

 DARWIN, F.R.S., and D. F. M. PERTZ . 



PRINTED FOR THE ROYAL SOCIETY and sold by 

 HARRISON & SONS, 45, ST. MARTIN'S LANE, LONDON, W.C. / 



Price Two Shillings and Sixpence. 



No. B 569. 



July 20, 1911. 



