AMERICAN 
JOURNAL OF BOTANY 
Vol. I December, 1914 No. 10 
THE EXPULSION OF ASCOSPORES FROM THE PERITHECIA 
OF THE CHESTNUT BLIGHT FUNGUS, ENDOTHIA 
PARASITICA (MURR.) AND. 
F. D. Heald and R. C. Walton 
Introduction 
General historical consideration of ascospore expulsion from peri- 
thecia. — The scope of the present article will not permit an exhaustive 
treatment of the subject of spore expulsion, but it seems desirable to 
point out at the beginning some of the more noteworthy observations, 
and especially those which apply to pyrenomycetous forms. 
Forcible expulsion of spores as a means of aiding in their dis- 
semination takes place in many fungi and is accomplished in a variety 
of ways. The projection of the entire sporangia as in Piloholus 
crystallinus, or of the single spores as in species of Empusa and 
Entomophthora, are well known illustrations. Cases of forcible 
expulsion of spores by Ascomycetes have long been known, and more 
recently similar phenomena have been demonstrated for Hymeno- 
mycetes (4, 7) and Uredinales (5, 7). Although the height of projec- 
tion is never great it is incomparably greater in the ascomycetes (few 
mm. to 15 cm.) than in the basidiomycetes, as has been pointed out 
by Falck (8). 
Directing our attention to Ascomycetes, the simultaneous ejection 
of the spores from a considerable number of asci giving rise to " pufhng" 
may be noted. This phenomenon has been known since the time of 
Persoon (1798) and Desmazieres for the larger Discomycetes, and 
according to De Bary (6) simultaneous ejection of the spores from the 
[The Journal for November (1: 441-498) was issued 4 Dec. 1914.] 
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