er,
thread-like stem. Other species of _Peziza_ are also known to be
developed from similar bases, and these Fuckel has associated
together under a proposed new genus with the name of _Sclerotinia_.
Two or three species of _Typhula_, in like manner, spring from forms
of _Sclerotium_, long known as _Sclerotium complanatum_ and
_Sclerotium scutellatum_. Other forms of _Sclerotium_ are known, from
one of which, found in a mushroom-bed, Mr. Currey developed _Xylaria
vaporaria_, B., by placing it on damp sand covered with a bell
glass.[L] Others, again, are only known in the sclerotioid state, such
as the _Sclerotium stipitatum_ found in the nests of white ants in
South India.[M] From what is already known, however, we feel justified
in the conclusion that the so-called species of _Sclerotium_ are a
sort of compact mycelium, from which, under favourable conditions,
perfect fungi may be developed. Mr. Berkeley succeeded in raising from
the minute _Sclerotium_ of onions, which looks like grains of coarse
gunpowder, a species of _Mucor_. This was accomplished by placing a
thin slice of the _Sclerotium_ in a drop of water under a glass slide,
surrounded by a pellicle of air, and luted to prevent evaporation and
external influences.[N]

As to the cultivation of moulds and _Mucors_, one great difficulty has
to be encountered in the presence or introduction of foreign spores to
the matrix employed for their development. Bearing this in mind,
extensive cultivations may be made, but the conditions must influence
the decision upon the results. Rice paste has been used with advantage
for sowing the spores of moulds, afterwards keeping them covered from
external influences. In cultivation on rice paste of rare species, the
experimenter is often perplexed by the more rapid growth of the common
species of _Mucor_ and _Penicillium_. Mr. Berkeley succeeded in
developing up to a certain point the fungus of the Madura Foot, but
though perfect sporangia were produced, the further development was
masked by the outgrowth of other species. In like manner, orange
juice, cut surfaces of fruits, slices of potato tubers, etc., have
been employed. Fresh, horse-dung, placed under a bell glass and kept
in a humid atmosphere, will soon be covered with _Mucor_, and in like
manner the growth of common moulds upon decayed fruit may be watched;
but this can hardly be termed cultivation unless the spores of some
individual species are sown. Different solutio