Heald-Studh ALTER : Expulsion of Ascospores 129 
specimen showing expulsion began its activity varied from ii to 
58 days. 
Many of the specimens showed a marked and characteristic in- 
crease in the number of active ostioles after the beginning of 
spore expulsion. There appears to be a gradual increase' to a 
maximum of activity with more or less fluctuation after the 
maximum has been reached. This peculiarity is illustrated by 
the record for a number of typical specimens as presented in the 
accompanying table (Table II). In the majority of cases the 
record was not continued beyond the maximum of activity. 
The Viability of the Spores Expelled from Desiccated 
Perithecia 
The longevity of ascospores of the chestnut blight fungus has 
been reported from tests made on material stored under different 
conditions. According to Anderson,® ascospores ejected from 
perithecia on to glass slides continued viable for five months and 
six days, while Anderson and Rankin^ report that spores taken 
directly, from perithecia in desiccated bark retained the power to 
germinate for a much longer period. Their statements on this 
point are as follows : “ At the end of one year very little diminu- 
tion in the percentage of germination could be seen.” “ In 
another series of experiments a large percentage of ascospores 
similarly stored germinated after eighteen months.” No germ- 
ination tests were reported of spores expelled from desiccated 
perithecia, but judging from their results on spores taken direct 
from dried material, one would expect a good germination of 
spores expelled after a prolonged drying of the bark. 
During the progress of the work on spore expulsion reported in 
this paper, germination tests of the expelled spores were made. 
In each determination the percentage of viable spores was de- 
termined in duplicate cultures by the hanging-drop method. A 
spore print from a given specimen was covered with sterile water 
and rubbed up with a sterile loop to secure a uniform suspension, 
and the culture made by transferring spores from this suspension 
“Anderson, P. J. The morphology and life history of the chestnut blight 
fungus. Bull. Pa. Chestnut Tree Blight Comm. 7: 1-44. 1913. 
'' Loc. cit. 
