it, Y the provisions of the will of the late Dr. William Johnson Walker 
if er B two prizes are annually offered by the Boston Society oF NATU- 
dl RAL History for the best memoirs written in the English language 
on subjects proposed by a Committee appointed by the Council. 
Prizes For the best memoir presented a prize of sixty dollars may be awarded ; 
if, however, the memoir be one of marked merit, the amount may be 
increased to one hundred dollars, at the discretion of the committee. 
F For the next best memoir, a price not exceeding fifty dollars may be 
: awarded. 
Satural Prizes will not be awarded unless the memoirs presented are of ade- 
3 quate merit. 
: The competition for these prizes ts not restricted, but ts open to all. 
: Attention is especially called to the following points : 
. In all cases the memoirs are to be based on a considerable body of 
original and unpublished work, accompanied by a general review of the 
made directly in competition for the prize. 
al Each memoir must be accompanied by a sealed envelope enclosing the author's name 
Lega with a motto corresponding to one borne by the manuscript, and must be in 
Se of the Secretary on or before April 1 of the year for which the prize Is offered. 
Dike a0 FOR 1901: Monograph on any problem connected with or any group belonging 
* North American fauna or flora. 
eta 1892: (1) Nuclear fusions in plants. (2) The fate of specific areas of the 
as determined by local destruction. The reactions of organisms to solu- 
om the standpoint of the chemical theory of dissociation. 
Theos C. F. BACHELDER, Secretary. 
ON Soctety or NATURAL HIstTory, 
Boston, Mass., U.S. A. 
: 
of OOD paper and printing, 
North Ameri G printing on one side of 
ie can page only, larger tyP® 
| Plants, ee J os genera arranged and numbered 
if according to the Engler & 
and exten- 
are fea- 
Prantl sequence, 
sive use of synonyms, 
tures of this edition. 
SECOND EDITION 
tte 
Price $1.00 per COPY paper 
covers, or $1.25 bound in cloth. 
ad 
| a 
| =, HELLER “ 
: wha Walnut street Sample pages may 
Lanca 
; STER, , U.S. A: upon application. 
be had - 
