410 POLYMORPHIC FUNGI. 
ceous than membranaceous, are reticulated, bringing to mind the 
same structure in Erysiphe, to which the perithecia bear consider- 
able resemblance. The ostiolum is so obscure that we could not 
be satisfied of its existence, or whether the perithecia are ruptured 
when mature. It is rather from analogy than positive evidence 
that the name of Spheria is given (Fig. 80, a). The interior of 
the perithecia is occupied by a gelatinous substance consisting of 
long cylindrical sacs or asci, each containing eight globose, color- 
less sporidia (Fig. 80, b). These are accompanied by slender 
branched threads, called paraphyses, supposed to be abortive asci. 
At first, and for some time, the perithecia contain only a granular 
mass, at length mixed with paraphyses. The contents of the fer- 
tile asci are also at the first granular, and 
Fig. 80, 
finally the sporidia are perfected. 
We have now described, as fully as 
seemed to be necessary, the four forms of 
fungi which vegetated during last winter and 
spring on our damp wall. What presump- 
tion have we that they belong to one and 
the same fungus—direct evidence there is 
none —or should they be regarded each as 
autonomous? We have already intimated 
the difficulties which beset all attempts to 
obtain positive evidence in such cases. Al- 
ready too many theories have been based on, 
a, Peritheciumof Sphe- OY supported by, supposed results from the 
with sporlaia > para. Cultivation of fungi spores. Many ridicu- 
ae lous assertions have been made by those 
who have thus exhibited their thorough ignorance of even generic 
distinctions, to say nothing of more complex relations in mycol- 
ogic science. Still we are by no means prepared to doubt that 
many of the recorded cases of polymorphism will ultimately be 
proved to be fact, and that many more will yet be discovered. 
We would admit that it is possible that none of the species, now 
included in the two great families of Coniomycetes and Hyphomy- 
cetes are autonomous. But, because it is possible, it by no means 
follows that we are prepared to condemn them by wholesale, or to 
admit that there is at present, any evidence for doubting the auton- 
omy of some entire genera. In the present condition of the 
study, and in the face of some startling facts, it is important that 
