.120 
N. C. AGRICULTURAL EXPERIMENT STATION. 
probable that the presence of the paper simply inhibited the forma¬ 
tion of the disks, not of the stipe of the ascophore. Light is evidently 
the stimulus which causes the tip of the sprouts which come from 
Fig. 24.—-Ascophores, showing new disk formation after mutilation. 
the sclerotium to stop growing in length and to expand into the 
disks and the presence of the paper covering was probably sufficient 
to exclude the light and thus to prevent this reaction. 
As shown on page 118 heat or cold beyond certain limits retards 
or inhibits the formation of ascophores. The maximum temperature 
for ascophore formation seems to be about 8 to 25 degrees C. 
The Ascospores. 
The ascospores, as has frequently been noted, are discharged quite 
forcibly into the air when mature. To observe this phenomenon sclero- 
tia-bearing disks were grown in flower pots and covered with plates of 
glass, or kept in tea cups covered with damp cloth. Upon the removal 
of the covering clouds of spores were forcibly ejected and could be fol¬ 
lowed by the eye for a distance of several feet. Currents of air caused 
by any one passing rapidly by ripe disks in open pots caused the ejection 
of spores. Spores for study were readily secured at any time by placing 
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