I suspect to be an abnormal state of a well-known Sphaeria (_S.
lanciformis_), which grows upon birch, and upon birch only.

We might multiply, almost indefinitely, instances amongst the
_Sphaeriacei_, but have already given sufficient for illustration, and
will therefore proceed briefly to notice some instances amongst the
_Discomycetes_, which also bear their complete or perfect fruit in
asci.

The beautiful purple stipitate cups of _Bulgaria sarcoides_, which may
be seen flourishing in the autumn on old rotten wood, are often
accompanied by club-shaped bodies of the same colour; or earlier in
the season these clavate bodies may be found alone, and at one time
bore the name of _Tremella sarcoides_. The upper part of these clubs
disseminate a great abundance of straight and very slender spermatia.
Earlier than this they are covered with globose conidia. The
fully-matured _Bulgaria_ develops on its hymenium clavate delicate
asci, each enclosing eight elongated hyaline sporidia, so that we have
three forms of fruit belonging to the same fungus, viz. conidia and
spermatia in the _Tremella_ stage, and sporidia contained in asci in
the mature condition.[X] The same phenomena occur with _Bulgaria
purpurea_, a larger species with different fruit, long confounded with
_Bulgaria sarcoides_.

On the dead stems of nettles it is very common to meet with small
orange tubercles, not much larger than a pin's head, which yield at
this stage a profusion of slender linear bodies, produced on delicate
branched threads, and at one time bore the name of _Dacrymyces
Urticae_, but which are now acknowledged to be only a condition of a
little tremelloid _Peziza_ of the same size and colour, which might be
mistaken for it, if not examined with the microscope, but in which
there are distinct asci and sporidia. Both forms together are now
regarded as the same fungus, under the name of _Peziza fusarioides_,
B.

The other series of phenomena grouped together under the name of
polymorphism relate to forms which are removed from each other, so
that the mycelium is not identical, or, more usually, produced on
different plants. The first instance of this kind to which we shall
make reference is one of particular interest, as illustrative of the
old popular creed, that berberry bushes near corn-fields produced
mildewed corn. There is a village in Norfolk, not far from Great
Yarmouth, called "Mildew Rollesby," because of its unenviable
notoriety