36 
RErRODUCTION OF THE ASCOMYCETER. 
and to bind together the series of forms by some more solid chains 
and some more immediate intermediaries. 
We have insisted above upon the great resemblance which exists 
between the spermatia and the conidia, an analogy already signa- 
lised by M. Tulasne. It is necessary, before undertaking the com- 
parison of the different sorts of organs, to convince ourselves of 
this analogy. It is also to be found among the stylospores, in an 
almost equal degree, in such a manner that one ought not to be 
astonished to find free, and not situated in any conceptacles, the 
spermatiferous or stylosporic arbuscles. These last, when they are 
free, have been considered as like the first, and their spores have 
likewise received the name of conidia. It thus happens that under 
this name of conidia are found designated hoth spermatia and 
stylospores : it thus becomes necessary to separate with care these 
two cases, and to be thoroughly clear as to which belong to this or 
that category. But this second case is much more rare than the 
first. Melanconis offers a series of remarkable examples ; one 
sees, among different species of this genus, some veritable sper- 
matia associated with a second sort of spores named conidia, because 
they are born free upon the stroma; but their thick membrane, 
their deep colour, their general analogy with the stylospores of 
Massaria and Cucurhitaria, shows that we have really to do with 
free stylospores. 
When one skilfully makes a delicate cut across a spermogone it 
is not rare, above all if one is dealing with an organ in full organic 
activity, to encounter upon the spermatiferous arbuscles, in all the 
stages of development, the spermatia still attached to the extremity 
of the branches. It is necessary, in order to study this properly, 
to operate upon living plants ; if one has recourse to dried organs, 
one finds great difficulty in getting a proper observation ; the cuts 
appear to be more easily obtained at the expense of a tissue w'hich 
takes the consistence of wax, but the observation of the details is 
incomparably less easy. 
The spermatia are developed in the following manner : — 
At the extremity of the more or less elongated lateral branches 
some small swellings are formed ; the sterigmate fringed in points 
is slightly swelled ; the small part developed at its extremity be- 
comes more or less elongated, but without its diameter much in- 
creasing; it preserves the transversal dimension of the filament 
which has given it birth. Sometimes the small spore remains rec- 
tilinear, sometimes on the contrary, and this is more frequently the 
case : it is slightly curved like a bow, in the case where the sper- 
matia are very long, they are almost always strongly curved (Dia- 
trype, Aglaospora, Quaternaria.) It is difficult to decide, as we 
have attempted to do with the spores of the Hymenomycetes,v^A\ewQe 
is derived this new formation, and what change the plasma under- 
goes at the extremity of the sterigmate ; the most energetic 
swellings appear still insufficient. 
As long as it has not acquired its final volume, the sperma- 
