510 F. D. HEALD AND R. C. WALTON 
Table III 
Amount of Ascospore Expulsion at Different Temperatures 
Specimen and Trap 
Numbers 
Average Temperatures 
F. 
No. of Active Ostioles per 
Trap per Day 
Amount of Expulsion 
II-18; 26-38 
38.6 
0 
None 
52-71 
53.8 
1.4 
Very light 
293-304 
56.25 
12.5 
Light 
I5O-I6I 
62.5 
17.7 
Light 
71.9 
( 72.6 ] 
Abundant 
< Average for all > 
{ controls J 
245-256 
79 
84-5 
Abundant 
269-280 
84.6 
32.06 
Medium 
233-244 
90.8 
5-5 
Very light 
98.4 
0.4 
Traces 
It would appear from this comparison that continued ascospore 
expulsion is dependent to a certain extent upon growth. This is also 
substantiated by the tests made on the duration of ascospore expulsion 
as recorded in the following pages. 
Duration of Ascospore Expulsion 
Probably one of the most remarkable facts to be noted in regard 
to ascospore expulsion under artificial conditions is the power which 
the perithecial stromata have to expel spores for an almost indefinite 
period, provided they are given the proper temperature and moisture 
conditions. 
On December 24, 191 2, 23 specimens collected at Emilie, Pa., two 
days before, were prepared and a duration experiment started at 
laboratory temperature using the same method as for the temperature 
tests. Daily records were taken for 5 months and 17 days and at the 
end of this time, June 9, 1913, all but three of the specimens showed 
some active ostioles. One of these three specimens was overgrown by 
molds and undoubtedly had ceased shooting permanently but the 
other two, according to their former records, would probably have 
started up again. One peculiarity of ascospore expulsion is the 
fact that when first brought in from the field, the perithecia will 
generally shoot spasmodically for some days, that is, they will expel 
spores abundantly for one, or sometimes two or three days in succes- 
sion, and then drop off to a very small amount. Then the succeeding 
days they will either gradually pick up and shoot abundantly for two 
