CHAPTER III,—SPORFS OF FUNGI. 97 
ascus-wall which surrounds them, and the protoplasm disappearing they at length 
entirely fill the cavity of the ascus; the wall of the ascus then forms a delicate septum 
between each pair of spores, and not unfrequently appears constricted between each 
pair c, but the septa are at length broken through in Sphaerophoron and most of the 
Calycieae, and the spores are thereby set free from one another and are collected 
together as a loose dust on the surface of the hymenium. In Lichina and Paulia the 
spores remain firmly united together. 
The phenomenon which we are considering is very common in asci which ripen 
in closed receptacles. Chaetomium (Zopf) and Melanospora parasitica! may be 
mentioned first as trustworthy examples among the Pyrenomycetes. In these species 
the wall of the ascus swells when the spores are ripe into a copious jelly, which increases 
in volume by absorption of water to such an extent that it issues out of the orifice of 
the perithecium and brings out with it the spores which are imbedded in it. The 
tissue surrounding the asci also swells up and adds to the quantity of jelly employed 
in the way described. The mass of spores thus forced out of the perithecium collects 
at its orifice in the form of drop-like aggregations or twisted tendril-like filaments like 
a tough mass squeezed through a narrow tube. This mode of emptying of asci and 
perithecia is very common in Pyrenomycetes with thin-walled asci, occurring probably 
in species of Nectria®, in Hypoxylon concentricum, Nummularia, Stictosphaeria, 
Eutypa, Quaternaria, and many other Xylarieae and Valseae described by Tulasne°. 
But more exact observation of individual cases is still required with reference to the 
considerations mentioned in this section. Perithecia without an orifice like those of 
Chaetomium fimeti and Cephalotheca tabulata * burst by the swelling of the gelatinous 
substance in a fixed manner. 
The asci of Eurotium, Penicillium, Anixia truncigena®, Onygena, Elaphomyces, 
and the Tuberaceae, which are also developed in closed receptacles but with no natural 
aperture, and opening only in consequence of decay or some accidental lesion, are 
dissolved or decomposed sometimes after temporary gelatinous swelling ; they disappear 
entirely and allow the spores to enter free and unconnected into the cavity of the 
receptacle. 
Section XXVIII. The liberation of the spores takes place in almost all 
cases as soon as they have reached maturity, that is as soon as they are fully devel- 
oped, and this as arule precedes the commencement of germination. Inthe few excep- 
tions to the rule, which are rendered more remarkable by its generality and apparent 
necessity, the spores when they are liberated from the ascus increase considerably in 
size either at the expense of their environment or of the reserve material which they 
themselves contain, till they have reached the degree of development which strictly 
corresponds to the state of maturity. Elaphomyces is specially noteworthy in this 
respect‘, in which the spores, after they are set free from the perishing asci, grow to 

1 Kihlmann, Zur Entw. d. Ascomyceten (Act. soc. Fennicae), XIII, 1883. 
? Janowitsch in Bot. Ztg. 1865. 
* Carpol. II. 
* Zopf in Sitzgber. d. naturf. Freunde, see p. 85, and for Chaetomium, Nov. Act. Acad. Leopold 
Bd. 42, Nr. 5 (1881). 
5 H. Hoffmann, Icon. Analyt. III, p. 70. 
° See De Bary, Fruchtentw. d. Ascomyceten, p. 33. 
[4] H 
