REPRODUCTION OF THE A8COMYCETES. 
37 
tium remains adherent to the filament ; it is separated by a rather 
sensible contraction, and it is there that the separation in two of 
the partitions takes place, which isolates the spore from its support. 
These small bodies are surrounded by a sort of mucus which 
appears to be exuded by each of them, and probably also by the 
filaments which gave them birth ; this is very visible in the Lichens : 
when this mucus is swelled out under the influence of moisture, 
the spermatia are driven to the outside. 
What has just been said applies wholly to the better character- 
ized conidia ; we shall see, in fact, by the examination of different 
conidia apparatus, the extreme resemblance which they present to 
the typical forms of the spermatiferous filaments. 
The veritable stylospores (in restricting this name to the asexual 
forms which accompany the spermatia, microstylospores or micro- 
conidia) offer an ensemble of characters easily recognisable in certain 
cases. They are produced at the extremity of filaments, in general 
short, which line the cavity of the pycnidia, or which may be free 
and pluricellular. The extremity of the filament, primitively 
rounded or obtuse, swells out in a considerable fashion so as to 
exceed one or more times its proper diameter. At the same time 
as this swelling a considerable elongation manifests itself ; if the 
stylospore is to present several partitions, they are produced at this 
instant. When the stylospore has attained its definite form it is 
still attached to the filament, and its membraneis still uncoloured ; 
this membrane is not slow to thicken itself, but in order that the 
spore acquire its definite aspect it has frequent need of being 
submitted to contact with the air. The action of the air deter- 
mines a peculiar browning of the more external part, notwithstand- 
ing the more internal part remains colourless : this last remains 
delicate, although the other is become notably increased and modi- 
fied, in certain cases even the thickness of the partition is a con- 
siderable fraction of the contents of the spore. When the germi- 
nation takes place, this external membrane bursts, and it is the 
inside which makes a rupture at the exterior. 
It is not rare to see the spore embellished with prolongations, 
points, a fringe which takes no part in this blackening : certain 
cells, in general those of the poles, are sometimes in this case. 
The modification exerted by the action of the air is manifest upon 
the stylospores of Massaria eburnea^ and upon the very probably 
stylosporic form described separately under the name of Diplodia. 
M. Tulasne has signalized both these facts, and refers to the last in 
more than one passage of his work. 
The same as Diplodia, the Hendersonia and Pestalozzia ought 
probably to be considered as stylosporic forms of Ascomycetes. 
Sometimes the stylosporous formation is more complicated ; one 
may cite Prosthemium betulinum, a stylosporic apparatus of Mas- 
saria siparia, according to M. Tulasne, a Prosthemium placed in 
similar relation to Nectria armeniaca, and the curious Asterospm- 
rium Hoffmanni, evidently an ally of the preceding species, but the 
