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: 

 Cbablzs Louis Pollard, Founder 



JosKPB Charles ARTHtrR 



Purdue Uni\er8ity 

 Otib VVilli.vm Caldwell 



Teacher's College, Columbia University 

 William Austin Cannon 



Desert Laboratory 

 J. Arthur Harris 



Station for Experimental Evolution 

 Burton Edward Livinqbton 



Johns Hopkins University 

 Francis Ernest Lloyd 



McGill University 

 Edwin Bennett McCallum 



Continental Rubber Company 



Daniel Trembly MacDouoal 



Carnegie Institution of Washiugton 

 Jambs Bertram Overton 



University of Wisconsin 

 George James Peirob 



Stanford University 

 Herbert Maule Richards 



Columbia University 

 Forrest Shreve 



Desert Laboratory 

 John James Thornber 



University of Arizona 

 Edgar Nelson Tranbeau 



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 early 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 approximately the following rates: 



Advertising rates will be furnished on application. 



Address all correspondence regardintj 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; Volumes 10 

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

 S2.50 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 payable to The Plant World. Address all correspond- 

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

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

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

 Arizona. 



