106 
REPRODUCTION OP THE ASCOMYCETES. 
on the contrary, placed upon a substance which does not suit them, 
remain without germinating, and wait until they are transported 
elsewhere. When the germination is very backward, which 
consists at first of an increase in diameter, they may still be sw^ept 
away during a sufficiently long period, and develop themselves 
upon a perfectly identical substratum, upon which no spore was 
yet disposed. 
If we examine the species which do not possess any spermatia, or 
at least which possess only one sort of spore, the germination of 
which is easy, we may, perhaps, obtain an idea of the physiological 
role of the speraiatia. Among the Pyrenomycetes we shall find 
Hypoxylon, Xylaria, Poronia^ &o., and the corresponding group of 
coloured Sphceria {Torrubia, Cordyceps) ; the Discomycetes offer 
us other genera, Peziza, AscohoJus, etc. All these genera are 
developed upon slightly compact bodies, old dead wood which is 
easily traversed, organisms living or diseased, dung, etc. These 
spores which genninate easily, in general are found singly ; it 
appears that this suffices, with the endospores, to assure the pene- 
tration of the species into substances which ofi'er no resistance to 
their immediate development. Such is the general fact, but some 
exceptions may present themselves. 
Without attaching more importance than is necessary to these 
theoretical considerations, we may with good reason be astonished 
at the facility with which Fungi exhibit themselves upon dead 
branches. It is rare to find such, which are not attacked by an 
Ascomycete, even whilst they are still attached to the tree. 
The idea of a spontaneous generation ought not to present itself 
to the mind for a single instant. Instead of admitting the direct 
transport of the spores each year, we may solve some great diffi- 
culties by proposing a rather plausible explanation. The parasite 
deposited in the condition of spermatia most generally (or of some 
other sort of spore), so that it can lodge itself in a chink of the 
bark, germinates upon the pabulum which suits it ; it struggles 
against the foster plant which defends itself, and probably bars the 
route to the mycelium by a partitioning of its cells, as we often 
see examples. The Fungus at first remains confined to a small 
area, in which it is almost stationary — a small space of dead 
tissue, or the base of a leaf partially detached. When at last the 
branch is killed, perhaps subdued by the struggle, the parasite, 
installed some long time before, is finally dispersed through the 
mass of the wood which it seizes upon entirely. This explains the 
rapidity of the development of the Ascomycetes upon cut and 
fallen branches, or even those which are killed upon the tree ; 
each dead branch is very soon covered, at the epoch favourable to 
the fructification, by a species often special to itself. 
Such should be the role of the true spermatia. 
W e may remark that the order of appearance is generally as 
follows : the spermatia are developed first of all, then the stylo- 
spores, finally the endospores. Thus, when there are none of the 
