38 
RErUODUCTION OF THE ASCOM i'CETES. 
typical form of whicli is not clearly established. One may see the 
different periods of the development of Prostliemium hetulinwn, 
certain prolongations of which remain sterile, although others 
grow and become partitioned. One will consult with interest the 
Set. Fung. Carpolugia (Vol. ii., p. 234 and 242, and t. hi., p. 76), 
where the near relation of these species is treated of. 
It is probable that the genera Triposporium, Corda, Hiruclinaria., 
Ces., Speii^a, Corda, Dictyosporiurn, Corda, &c., are very nearly 
related to the preceding forms, and these last insensibly conduct 
us to the Pleospora, Fumagu, and other species, of which the mem- 
brane of the filaments and of the conidia becomes browned in the 
air, and becomes incrusted, although the small spores described by 
M. Tulasne as stylospores offer a greater resemblance to the micro- 
stylospores or spermatia. But, as my studies upon the different 
species of these groups have not been complete enough, I am 
forced, to my great regret, to stop myself sharply here without 
conclusion relative to these two last genera, and to retake the sub- 
ject studied more specially, that is to say, the morphology of the 
spermatiferous apparatus. 
For the particular study of the spermatiferous organs, it is 
necessary at first to take, as a starting-point, the organs assimilated 
to the spermogonia of the Lichens, and designated by the same 
name among the Ascomycetes. The spermatiferous arbuscles 
are formed of straight filaments, each cell of which is prolonged 
laterally at the underside of the cell which surmounts it ; the short 
branch thus formed is the bearer of a small spore of variable form, 
but with a simple membrane and dense plasma. These are veritable 
conidia ; the cells which give them birth are at times short, as in the 
Pliyscia ciliaris, at others, on the contrary, more elongated, Parmelia 
acetabulum. 
Among most of the Ascomycetes the spermatiferous arbuscles 
affect a very analogous form. Among certain species they are 
constituted by short cells prolonging themselves into short lateral 
sterigmates ; it is easy to see that these are some formations very 
nearly allied to those of the Lichens. Among other species the 
cells of the filaments are much more slim, the sterigmates consti- 
tuting veritable lateral branches, and sometimes some of them are 
separated from the others by partitions ; it is not rare to see at 
that time many born at the same height. Their nature is very 
evident when they prolong a joint of the filament, but one easily 
passes in thought from this case to that wLere the sterigmate is 
isolated and becomes itself a lateral cell. It is this which is the more 
frequently encountered in the Ascomycetes, and wdiich has been 
represented in Valsa ambiens. This form scarcely differs from the 
preceding, and M. Tulasne proclaims it as identical wdth the other. 
It is a very general modification of the filament which bears the 
spermatia ; this would be noticed in turning over the plates of the 
Selecta Fungorum Carpologia. 
