THE CLASSIFICATION OF DI8COM YCETES. 
47 
The group of Discomycetes, dehiscing by an operculum, presents 
some characters which give an appearance of close relationship to 
all the species belonging to it. Thus the sporidia of all those 
with which I am acquainted are simple ; that is to say, they are 
without septa, sphasrical, or more frequently, oval, or elliptical in 
shape, with their extremities rounded, rarely acuminate. They are 
often warty and sometimes are reticulated. The consistence of the 
cups is almost always waxy, less elastic than in the second division, 
except in some rare exceptions. The hairs which are sometimes 
found on the exterior are generally of a different structure. The 
greater number of the species are found on the earth, on dung, 
the soil of old trees, or rarely they are met with on sound dead 
wood or on the bark. This first division includes the Morels, the 
Helvellas, the Verpas, the Pezizaa of the sections, Aleuria, Humana, 
many of the Lachnece, A scobolus and the greater part of the genera 
which are derived from this section. 
The second division, the Inoperculce, is clearly separated from 
the first. There is no longer a transverse or oblique slit at the 
extremity of the ascus ; the extremity itself becomes softened in 
the centre at the moment of maturity, and the tension which is 
then produced ruptures it, permitting the escape of the sporidia 
with the liquid in which they exist. By the fact of this emission, 
the margin of the opening becomes more or less turned like a 
collar, either entire or slightly toothed, remaining often very 
visible, as in P. tuberosa , P. rapulum , and P. echinophila ; but 
sometimes also closing together, so that in order to distinguish the 
opening, it is necessary to prove its existence by squeezing the thin 
walls of the ascus together, as in the small Mollisia , Mitrula, &c. 
Most frequently, the extremity of the ascus presents a broad 
truncated nipper, very thin in the centre. 
The species of this section frequently have sporidia with a 
tendency to division, or they are clearly divided ; and very often 
they are simple, but become divided at the time of germination. I 
know of none that are verrucose or areolate; they are rarely 
sphaerical, but most frequently fusiform, more or less elongated, 
and sometimes club-shaped; many are more or less curved, and in 
general they are much smaller than those of the species in the 
first section. The consistence of the cup is more firm and elastic, 
and much less waxy ; the hairs when they exist have a different 
appearance. The species are rarely terrestrial, being much 
oftener found on dead wood, dead leaves and stems, and sometimes 
even on the living branches. This second division includes 
Geoglossum, Mitrula, Leotia, Phialea, Helotium, Lachnella, Mollisia, 
and all the genera belonging to them. 
There exists a little group of ascigerous fungi in which the 
mode of dehiscence is not yet well known : I allude to the true 
Tuberacem, Tuber, Elaphomyces, and others, that is in fungi com- 
pletely closed, in which the asci are altogether internal and 
cannot discharge their sporidia externally. I think that in 
