Mar. is, 1924 
Currant Cane Blight Fungus on Other Hosts 
843 
2-3 mm. on the smaller branches to 3-3.5 by 5-8 mm. near the base of the 
older canes where the bark was 2.5 mm. in thickness. Moreover, the 
host apparently affects to some extent the amount of stromatic tissue 
which develops about the perithecium. In the present study it was 
evident that the perithecia which matured on the inoculated rose plants 
had associated with them much less stromatic tissue than those which 
matured on inoculated currant plants (fig. 1, A, B). That the inoculum 
was identical in the two cases is assured by the fact that subcultures 
from a single ascospore culture were used in both cases. This observa¬ 
tion alone would suggest that mere size of stroma is an unreliable character 
for the identification of species in this group. 
SUMMARY 
Currant cane blight is now known to occur in Massachusetts, Connecti¬ 
cut, New York, Ohio, Pennsylvania, New Jersey, Maryland, and Virginia, 
but is less severe in the northern portions of this region. 
The disease is caused by a fungus to which the name Botryosphaeria 
ribis was given by Grossenbacher and Duggar, who first demonstrated 
its pathogenicity. 
A fungus identical morphologically and in cultural characters with the 
currant cane blight fungus has been collected by the writers on horse- 
chestnut and rose. 
Inoculations on currants with the fungus from both these hosts have 
produced typical cane blight. 
The fungus is apparently parasitic on several varieties of cultivated 
roses, and its pathogenicity has been established by inoculations on at 
least one variety. 
The size of the stromata in this fungus is apparently directly affected 
by the thickness of the bark in which it develops as the stromata are 
smaller in thin currant bark than in thick bark, and uniformly smaller on 
rose than on currant. 
In view of the agreement of the fungi from the different hosts in cul¬ 
tural characters, morphology, and parasitism, the conclusion seems amply 
warranted that they are identical, and that the fungus hitherto known 
only as the causal organism of currant cane blight does actually occur on 
other hosts. 
