CHAPTER III.—SPORES OF FUNGI. 91 
Section XXIII. The process of ejection in the Pyrenomycetes which discharge 
their spores simultaneously was first correctly described in Sordaria by Zopf?. 
Numerous asci placed upright side by side in a thick tuft fill the swollen enlarged 
basal portion of a flask-shaped receptacle, the perithecium, which is continued upwards 
into a more or less elongated neck. In large forms, as S. fimiseda, the neck is more 
than a millimetre in length but much shorter in the smaller species, and is traversed 
longitudinally by a very narrow canal, not so broad as an ascus, which enlarges into a 
conical form at its inner end above the group ofasci and is open to the air above at the 
outer end. Till the spores begin to ripen the asci are between narrowly cylindrical 
and club-shaped, and of the same height as the basal 
ventral portion of the perithecium. Then they begin to 
elongate one after another while they grow much broader 
at the apex. The only direction in which they can 
elongate is that of the canal of the neck. When the apex 
of the first ascus reaches the inner end of the canal, it 
enters it and swelling there to a broadly club-shaped 
form, and causing a corresponding enlargement of the 
canal, it continues to lengthen, till its apex is on a level 
with the outer mouth of the canal or a little above it; 
then its ejection takes place. Then the next ascus enters 
into the now empty canal, and so on one after another. 
The lower extremity of the ascus continues attached to 
its original point of insertion at the base of the peri- 
thecium until ejection. The elongation is therefore very 
considerable; in the case depicted in Fig. 44, for instance, 
it is more than six times the length attained by the ascus 
at the time the spores are ripe, and is at least three times 
that length beneath the widened upper part. The lower 
portion seems to become narrowed at the same time 
under the pressure of the neighbouring asci which are a 
FIG. 44. Sordaria minuta, Fuckel f}. 
beginning to swell, but it is difficult to be quite certain on Form with 4spored asci; small perithe- 
cium grown on a microscopic slide and 
this point on account of the strong lateral pressing to- observed in the living state lying in the 
culture-fluid, in optical longitudinal sec- 
gether of the parts. tion; at the base of the perithecium is 
ee M 2 5 a dense group of asci, most of them with 
The rapidity with which the elongations are accom- ‘ire spores; above this group are other 
3 " x a mature asci in various stages of elongation 
plished is comparatively small. In a small specimen preparatory to ejection, the u 
A having almost reached the opening of the 
observed in water the movement of the apex about a neck. Magn. about 100 times. 
spore’s length (= 17 x) occupied some 15 minutes, and 
the passage through the whole neck about 8 hours. In the specimen of Sordaria 
minuta (?) given in Fig. 44 the motion was quicker, a spore’s length of 10 » requiring 
some five minutes. How far light, heat and other external causes accelerate or 
retard the movement, and what are the specific differences which certainly exist, 
are points which have yet to be investigated. 


Section XXIV. The force with which the spores are ejected does not appear 
tobe great. In Bulgaria inquinans and Protomyces macrosporus they are sent straight 

1 As cited on p. 85. 
