22 NORTH AMERICAN SORDARIACEAE 
of development is taken into consideration it appears better to con- 
sider it an 8-spores ascus. But this opens up the question as to 
the definition of a spore into which it is best not to enter here. 
An inspection of 77. 18. f. 8 and 77, will show that here as 
in all of the Ascomycetes, there is a considerable portion of the pro- 
toplasm of the ascus unused in spore formation. In Pleurage this 
is comparatively large in amount, and from it are developed the 
gelatinous appendages of the spores. In the other genera of the 
family it forms gelatinous envelopes instead. All stages of gela- 
tinous appendage formation may often be traced in a single peri- 
thecium of such forms as P. taenioides or P. fimiseda. At first 
they are not visible at all, but as development proceeds they 
gradually appear as short lash-like projections on the ends of the 
spores. At this time they may be very distinct at the proximal 
end, while the distal one gradually fades away into the general 
protoplasmic reticulum of the ascus. As the appendages develop, 
the protoplasm decreases in quantity and gradually assumes a more 
homogeneous consistency, until at maturity, the granularity so char- 
acteristic of the early stage has almost if not quite disappeared. 
The appendages of a spore are almost never straight, but on the 
contrary curve around among other spores and their appendages, 
thus holding them together firmly but delicately to facilitate the 
process of spore ejection as described further on. 
SPORE DISSEMINATION 
Intimately connected with the structural and developmental 
peculiarities discussed in the preceding pages is the function of 
spore dissemination. To gain an adequate conception of this 
function one must necessarily be familiar with such phenomena 
as spore development, spore appendages, structure of perithecia, 
osmosis, turgidity and numerous other physical and structural de- 
tails intimately connected with the process itself. So far as 
development and structure are concerned the preceding pages 
enable us to proceed directly with the question in hand. Owing 
to differences in the method of scattering the spores adopted by 
different groups of the family, it will be necessary to discuss the 
dissemination in the different genera more or less separately. 
The classification of the group as here adopted is determined in 
