SCIENCE PROGRESS 



IN THE TWENTIETH CENTURY 

 I A QUARTERLY JOURNAL OF 

 \ SCIENTIFIC WORK 



I & THOUGHT 



VOL. VIII 

 NO. 31. JANUARY 1914 



EDITOR 



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

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



LONDON 

 JOHN MURRAY, ALI3EMARLE STREET, W. 



1914 



