38 BOTANICAL GAZETTE [ JANUAR 
gained in the selection and cultivation of varieties as little s 
ceptible to the disease as possible. We have to find out to w 
degree by crossing we can combine a small susceptibility to rus 
with a strong resistance to cold, and finally whether com 
regions may not tend to repress the development of the Be 
germ of the disease, and thus become regions for the producti 
of certain kinds of cereals. 
The questions above mentioned are of.great practical int : 
tance, and they suggest a very rich field for further investigatio 
STOCKHOLM, SWEDEN, 
