256 
Usually he spores of this species are borne singly, but in one 
particularly luxuriant pure culture they were found in chains as 
is here shown. This places the species in the genus A/fernana. 
The other species, which ought to be known by the name 
Alternaria fasciculata, for reasons given below, is found abundantly 
_on the dead leaves of the potato, but all attempts at inoculation 
of living tissues failed to produce any infection, even under the 
most favorable green house conditions. 
During the same summer studies of fungus diseases of the 
onion were undertaken and on some of the dead onion leaves a fun- 
gus was found which so closely resembled A/ternaria fasciculata as 
to be indistinguishable from it. Spores of Alternaria fasciculata 
from a pure culture from potato leaves were sown on dead onion 
leaves still attached to a living plant. A rank growth of mycelium 
bearing the characteristic A/ternaria spores soon appeared on the 
inoculated spots, but none elsewhere. This experiment thor- 
oughly demonstrated the undiscriminating nature of the plant, 
for a fungus which will grow on dead leaves of onions and of 
potatoes can scarcely be restricted to any group or groups of 
plants. 
When later on in the summer the study of the tomato rot was 
taken up, it was found that the fungus which causes the black 
patches on the rotting fruit was an A/fernaria not distinguishable 
from the one on the onion and the potato. It was further proved _ 
that this fungus did not cause the rot, for green tomatoes inocu- 
