AMERICAN 
JOURNAL OF BOTANY 
Vol. I April, 1914 No. 4 
CONTRIBUTION TO THE LIFE HISTORY AND 
PHYSIOLOGY OF CYLINDROSPORIUM ON 
STONE FRUITS^ 
Bascombe Britt Higgins 
WITH PLATES XIII-XVI 
Introduction. 
The disease of plums and cherries caused by the fungus CyHndro- 
sporium has long been known, and because of its economic importance 
and peculiar appearance has for many years attracted the attention 
of horticulturists and plant pathologists both in Europe and America. 
On certain species of the hosts the disease becomes very conspicuous 
because of the "shot hole" effect on the leaves, produced by the 
dropping out of roundish areas of diseased tissue. From the leaves 
of other species however the spots do not drop out, and usually in such 
cases the leaf tissue is not killed to any appreciable extent. In cases 
of severe attack the leaves often turn yellow and drop prematurely, 
which of course interferes more or less seriously with food production 
and the future welfare of the tree. 
''Shot holes" are produced in the leaves of stone fruits by several 
different organisms or even by mechanical injury, for example, as the 
result of a needle prick. Duggar (8) found also that they were pro- 
duced readily by spraying plants with poisonous solutions. However, 
the fungus Cylindrosporium is probably the most prolific cause of 
this phenomenon, at least in cherries; and many collectors have 
apparently attributed all ''shot hole" effects on species of Prunus to 
Cylindrosporium padi Karst. 
1 Contribution from the Department of Botany, Cornell University. No. 155. 
[The Journal for March (1: 97-144) was issued 6 May 1914.] 
145 
