New York AGRICULTURAL EXPERIMENT STATION. 63 
may strangle a succulent terminal portion; or the fungus may 
kill the lateral shoots while the main stem remains green. On 
the older woody stems the spots are considerably sunken, but 
on succulent shoots this character is scarcely noticeable. The 
spots are elliptical, their major axes having a length of from 
three to ten millimeters and lying parallel to the axis of the 
shoot. At first they are dirty white with a narrow brown border. 
In a short time several minute pimples, which are at first brown 
but soon turn black, appear in the central portion. Microscopic 
examination shows these pimples to consist of a brown stroma. 
Neither spores nor sete are present at this time. It is in this 
black-pimple condition that the fungus is generally found. Still, 
under fayorable conditions of moisture the spots fruit profusely; 
and both spores and sete may be obtained in abundance at any 
time by placing spots- showing the black pimples in a moist 
chamber for about 48 hours. However, very old spots may refuse 
to fruit under any conditions. With the appearance of spores 
and setz the spots become quite black over the greater part of 
their surface. The acervuli are numerous and so crowded that 
it is difficult to distinguish the individuals even with the aid of a 
good magnifier. The stroma is dark brown and well developed. 
Several sete are borne on each acervulus. The majority of 
them are straight but some are bent. They are dark brown and 
taper uniformly to a moderately sharp point. As a rule they are 
3-septate, but 2-septate and 4-septate individuals are not uncom- 
mon. They are 50 to 100” in length and unbranched. 
The conida are non-septate, colorless and mostly about 43 
times as long as broad, measuring 16-21x4 The majority of 
them are slightly curved, with both ends rounded or else with a 
short obtuse point at one side of one end (Plate VI, fig. 3). The 
young conidia have granular contents and almost invariably a 
Single vacuole near the center; but with age more vacuoles appear 
and finally they become two to four nucleate. The writer’s obser- 
vations on plants in the greenhouse at Geneva lead him to believe 
that a high degree of humidity in the atmosphere is necessary 
