PROCEEDINGS 



OF 



THE ROYAL SOCIETY. 



Series B. Vol. 84. No. B 572. 



BIOLOGICAL SCIENCES. 



CONTENTS. 



Page 



The Influence of Ionised Air on Bacteria. By W. M. THORNTON. D.Sc, 

 D.Eng., Professor of Electrical Engineering at Armstrong College, 

 Newcastle-upon-Tyne. (Plates 7—12) 280 



The Permeability of the Yeast-Cell. By SYDNEY G. PAINE. Research 



Scholar in the Biochemical Department, Lister Institute, London . . 289 



The Intrinsic Factors in the Act of Progression in the Mammal. By 



T. GRAHAM BROWN . 308 



An Inquiry into the Influence of the Constituents of a Bacterial Emulsion on 

 the Opsonic Index. By A. F. HAYDEN, M.B., B.S., F.R.C.S., I.M.S., and 

 W. PARRY MORGAN, M.A., B.Sc, M.B 320 



The Morphology of Trypanosoma gambiense (Dutton). By Colonel Sir 



DAVID BRUCE, C.B., F.R.S., A.M.S. (Plate 13) 327 



The Behaviour of the Infusorian Micronucleus in Regeneration. By 

 KENNETH R. LEWIN, B.A., Senior Scholar and Coutts Trotter Student 

 of Trinity College, Cambridge . . . . . . . .332 



The Refractive Indices of the Eye Media of some Australian Animals. By 



JUDAH LEON JONA, D.Sc, M.B.. B.S 345 



printed for THE ROYAL SOCIETY and sold by 



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

 Price Four Shillings and Sixpence. 



No. B 572. 



December 8, 1911. 



