SCIENCE PROGRESS 



IN THE TWENTIETH CENTURY 



A QUARTERLY JOURNAL OF 



SCIENTIFIC WORK 



& THOUGHT 



EDITOR 



SIR RONALD ROSS, K.C.B., F.R.S., N.L., 

 D.Sc, LL.D., M.D., F.R.C.S. 



VOL. XI 

 19 i 6 — 19 1 7 



LONDON 

 JOHN MURRAY, ALBEMARLE STREET, W. 



1917 



