irregular _Antennariei._
Threads free--
Sporangia terminal or lateral _Mucorini._
Aquatic _Saprolegniei._

VI. Asci formed from the fertile cells of a hymenium ASCOMYCETES.
Asci often evanescent--
Receptacle clavaeform--
Asci springing from threads _Onygenei._
Perithecia free--
Asci springing from the base _Perisporiacei._
Asci persistent--
Perithecia opening by a distinct ostiolum _Sphaeriacei._
Hard or coriaceous, hymenium at length exposed _Phacidiacei._
Hypogaeous; hymenium complicated _Tuberacei._
Fleshy, waxy, or tremelloid; hymenium mostly
exposed _Elvellacei._

IV.

USES.

The rigid utilitarian will hardly be satisfied with the short
catalogue which can be furnished of the uses of fungi. Excepting those
which are employed more or less for human food, very few are of any
practical value in arts or medicine. It is true that imperfect
conditions of fungi exert a very important influence on fermentation,
and thus become useful; but, unfortunately, fungi have the reputation
of being more destructive and offensive than valuable or useful.
Notwithstanding that a large number of species have from time to time
been enumerated as edible, yet those commonly employed and recognized
are very few in number, prejudice in many cases, and fear in others,
militating strongly against additions to the number. In Great Britain
this is especially the case, and however advisable it may be to
exercise great care and caution in experimenting on untried or
doubtful species, it can only be regarded as prejudice which prevents
good, in fact, excellent, esculent species being more extensively
used, instead of allowing them to rot by thousands on the spots where
they have grown. Poisonous species are also plentiful, and no golden
rule can be established by means of which any one may detect at a
glance good from bad, without that kind of knowledge which is applied
to the discrimination of species. Yet, after all, the characters of
half a dozen good esculent fungi are acquired as easily as the
distinctions between half a dozen birds such as any ploughboy can
discriminate.

The common mushroom (_Agaricus campestris_) is the best known
esculent, wheth