Vol. LXIII. No. 3 JULY, 1903 



THE 



POPULAR SCIENCE 

 MONTHLY 



EDITED BY J. MoKEEJ^ CATTELL 



CONTENTS 



Hertzian Wave Wireless Telegraphy. Dr. J. A. Fleming 193 



Why a Flame emits Light. Professor Robert Montgomery Bird . . 209 



Evolution, Cytology and Mendel's Laws. 0. F. Cook 219 



The Pearl Fisheries of Ceylon. Professor W. A. Herdman .... 229 

 A Comparison of Land and Water Plants. Professor George James 



Peirce 239 



The Preservation of Wild Flowers. Frances Zirngiebel 246 



An Unfilled Field in American Agricultural Education. Kenyon L. 



BUTTERFIELD • • 257 



The Story of English Education. J. E. G. de Montmorency .... 262 



Discussion and Correspondence : 



The Question of Kacial Decline : C. E. Smith 275 



Scientific Literature : 



Psychology 278 



Progress of Science : 



Lord Kelvin on 'Creative Purpose ' ; Celebrations in Honor of Dal ton and Liebig ; 

 The American Museum of Natural History ; The American Philosophical Society ; 

 Scientific Items 2<9 



THE SCIENCE PRESS 



LANCASTER, PA. GARRISON, N. Y. 



NEW YORK : Sub-Station 84 

 Single Ncmbee, 30 Cents Yearly Subscription, |3.00 



Copyright, 1903, by THE SCIENCE PRESS 



