Experiments on the Brown Rust of Bromes 
(Puccinia dispersa). 
BY 
E. M. FREEMAN, M.S., 
University of Minnesota. 
T HE experiments from which the following results have 
been obtained were carried on in the botanical laboratory 
of Cambridge University, and I take pleasure in the acknow- 
ledgement of my indebtedness to Professor Marshall Ward 
for his many valuable suggestions and helpful direction, as 
well as for the excellent laboratory facilities afforded me. 
The experiments were undertaken for the purpose of obtaining, 
if possible, evidence on the brown rust of Bromes correlative 
to the recent work of Professor Ward 1 , viz. to test the in- 
fection capabilities of numerous species, among which were 
several whose systematic position in the genus has been 
somewhat doubtful, with spores from Br omits sterilis and 
B. mollis , using the reaction of plant and Fungus as an indica- 
tion of the systematic affinities. The work was begun March 
19 and closed June 18. The method of procedure was in 
general that used by Marshall Ward. Upon the first foliage 
leaf of seedlings of Brome plants, usually less than two inches 
high, were rubbed spores of the Uredo of B. sterilis and 
B. mollis respectively, a short distance from the apex of the 
leaf, or the spores were placed in the water-drop exuding 
from the water-stomata at the tip. The plants were then 
placed under moist bell-jars or beakers and kept in the labora- 
tory for about twenty-four hours ; they were then placed out 
1 Proc. Camb. Phil. Soc., vol. xi, pt. v ; Proc. Roy. Soc. ; Annals of Botany, xv, 
No. lix, 1901. 
[Annals of Botany, Vol. XVI. No. LXIII. September, 1902.] 
