V 



The Plant World 



A Monthly Journal of General Botany 



Established 1897 



Edited by 

 Forrest Shreve 



Published by 



The Plant World Association 



COMPOSED OF THE FOLLOWING MEMBERS: 

 Charles Lo0is-Pollabd, Founder 



JotEPH Chables Arthur . 



Purdue University 

 Otib William Caldwell 



Teacher's College, Columbia University 

 WiLLiAU Austin Cannon 



Deaert Laboratory 

 J, Abthub Harris 



Station for Experimental Evolution 

 BuBTON Edwabd Livingston 



Johns Hopkins University 

 Fbancib Ernest Lloyd 



McGill University 

 Edwin Bennett McCallum 



Continental Rubber Company 



Daniel Tbeublt MacDouqal 



Carnegie Institution of Washington 

 James Bertram Overton 



University of Wisconsin 

 Geobqe Jame!: Peirce 



Stanford University 

 Herbebt Maule Richards 



Columbia University 

 Forrest Shrevb 



Desert Laboratory 

 John Jambs Thornber 



University of Arizona 

 Edqab Nelson Transeau 



Ohio State University 



All manuscripts submitted for publication should be type-written and in good 

 order. Galley proof is submitted to the author who should return it as earl}' as 

 possible to the Editor. Reprints should be ordered on a blank for that purpose 

 which accompanies the galley proofs. 



Reprints will be supplied at cost, at approximatelj' the following rates: 



Advertising rates will be furnished on application. 



Address all correspondence regarding contributions and reprints, and all 

 books for review to The Editor, The Plant World, Tucson, Arizona. 



The subscription price is S2.50 per annum in the United States, its overseas 

 dependencies, and Canada and Mexico; $3.00 to other countries. Single copies 

 are 30 cents each. Volumes 1 to 7 inclusive can not be supplied; Vo'umes 10 

 and 11 can be supplied incomplete; Volumes 8 and 9, and Volumes 12 to 20 are 

 J2.50 each. 



Missing numbers lost in the mails will be replaced gratis only when notice 

 is received within one month of date of issue. 



Make all remittances pajable to The Plant World. Address all correspond- 

 ence regarding subscriptions, discontinuances, changes of address, back num- 

 bers and early volumes to: The Waverly Press, Williams & Wilkins Company, 

 2419-21 Greenmount Avenue, Baltimore, Md., or to The Plant World, Tucson, 

 Arizona. 



