THE EFFECT OF CONTINUED DESICCA- 
TION ON THE EXPULSION OF 
ASCOSPORES OF ENDO- 
THIA PARASITICA 
F. D. Heald and R. a. Studhalter 
The importance of ascospore expulsion in the dissemination 
of the chestnut blight fungus has been emphasized by various 
writers since the process was first observed by Rankin. A brief 
consideration of the work bearing on this phenomenon is pre- 
sented in the historical introduction to a recent article^ and will 
not be repeated here. 
The effect of continued desiccation on the expulsion of asco- 
spores has an important bearing on dissemination, since chestnut 
products bearing perithecial stromata are frequently transported 
for some distance. If these products are dried, the question has 
been raised as to how long the perithecia will retain their power 
to eject spores if subjected again to favorable conditions of 
moisture and temperature. 
Anderson and Babcock^ first brought out the fact by laboratory 
tests that expulsion of spores is resumed after desiccation if 
moisture is supplied. The longest period of drying recorded in 
this first work was seven days and this appeared to have little or 
no effect on the power of the perithecia to expel spores. In a later 
article by Anderson and Rankin®, the influence of long desiccation 
is reported as follows : “ The writers also found that the peri- 
thecia will retain their ability to eject spores for at least seven 
^ Heald, F. D. & Walton, R. C. The expulsion of ascospores from the 
perithecia of the chestnut blight fungus, Endothia parasitica (Murr.) Anders. 
Am. Jour. Bot. i : 499-521. f. i, 2. 1914- 
* Anderson, P. J. & Babcock, D. C. Field studies on the dissemination 
and growth of the chestnut blight fungus. Bull. Pa. Chest. Tree Blight Comm. 
3:1-45. 1913. 
’Anderson, P. J. & Rankin, H. W. The Endothia canker of the chestnut 
Bull. Cornell Agr. Exp. Sta. 347: 531-618. 1914- 
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