. Walker Prizes in Natural History. 
the provisions of the will of ei late Dr. William oe Walker two prizes are annually offered 
by the Boston SOCIETY OF NATURAL HISTORY for the best memoirs written in the English language, on 
sebjects proposed by a Dacidines cppbinted by the Council. 
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 dotinrs, at the Te of the Committee. 
For the : : 
Prizes will not be awarded unless the memoirs presented are o sane nent 
The competition for these prizes is not restricted, but is open to all, 
Luge is especially called to the following points 
all cases the memoirs are to be based on a considerable body of original and unpublished work, 
ato panied ~y a ahi review of the literature of the subject. 
. Anythin i n the hi oa ng ll furnish proof an the identity of the author shall be considered 
from Peompet 
s. Preterence will b t a showing intrinsic evidence of being based upon researches made 
deectly in competition for the priz 
4. Each memoir must be Seiciea a by a sealed steueete Te the author's name and super- 
embed with a motto corresponding to one borne by the manuscript, and must be in the hands of the Sec- 
mary on or before April 1st of the year for which the prize is 0 
§, The Society assumes no responsibility for publication of snatinclons submitted. 
Subjects for 1905: Subjects for 1906: 
t The life history of any parasitic fun ngus 1. An experimental Gord bres in CoOngTs: 
Ls Contin to our A 
pant 
nowledge of ‘the physiology of 2. A contribution to a k p 
tition in plants, 
3. A physiological life history of a single species of 
: Costrbution to the development of some group of fos- 
Rate in animals or plan plant. 
same? of geographical lsibution of species. 4. Phyloge ny ofa si fossil organisms. 
mas Study of the mechanism of Galeleveltie (pene- _ pisgrs ne ia mineral Dhysie 
et iettetion to ge we Shee ye lation in the United . petits Cera ae 
Boston Society of Natural History, Boston, Mass., U.S.A. GLOVER M. ALLEN, Secretary. 
—— 
Methods in Plant Histology 
y CHARLES J. CHAMBERLAIN, A.M., PH.D., Instructor in Botany in the University of Chicago 
eee a I ed 
A 
CONSTANT HELP to Teachers and Students of Botany 
CONTAINS DIRECTIONS FOR COLLECTING AND PREPARING 
PLANT MATERIAL FOR MICROSCOPIC INVESTIGATION 
§ bas 
Tete publ ¢d upon a course in ian penis technique, and is the an complete manual to 
ag pith on “pe su i c 
ch ; 
uch preparations as are needed by those who wis! 
e alge i up to the flowering plants. Special attention n is paid t 
ep euating rnd ce because the student who masters this problem wi 
2 onical labee uctures. Formulas are given for the reagents common 
ec m fro om t 
; “hs Tyokined aaa 
ad ic 
ly use ed in 
I 
am, 8vo, illustrated, cloth, (net) $1.50; postpaid $1.59 
For sale by dealers or by the publishers 
The Unive 
s_’*TSity of Chicago Press, Chicago, Illinois 
