260 
Journal of Agricultural Research 
Vol. V, No. 6 
From these cage experiments therefore it would appear that the wilt 
bacteria are carried over the winter by the hibernating beetles and inocu¬ 
lated into the cucumbers as they feed upon the young leaves. However, 
from the fact that wilt appeared in only one of the four cages into 
which beetles were introduced, it would seem that not all hibernating 
beetles carry the disease, but only those, or some of those, which have 
previously fed upon wilted plants. In other words, the beetles act not 
only as summer but also as winter carriers of the wilt organism from one 
cucumber plant to another. At least the above facts seem to warrant 
this as a tentative conclusion. The only possible alternative is to sup¬ 
pose that some of the beetles captured on June 17 and introduced into 
the four cages had recently had opportunity to gnaw diseased plants, 
which under the circumstances of their capture appears to the writer out 
of the question. Finally, in addition to the positive evidence of insect 
transmission afforded by this cage and by the one into which a beetle 
accidentally penetrated, as well as by daily observation on the check 
plants, there is the negative evidence afforded by the fact that in all 
cages from which beetles were excluded the plants remained free from 
the disease in two fields where it was very prevalent. 
