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 Urticæ_, 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 in days past for mildewed corn, produced, it was said, by the berberry bushes, which were cut down, and then mildew disappeared from the corn-fields, so that Rollesby no longer merited its _sobriquet_. It has already been shown that the corn-mildew (_Puccinia graminis_) is dimorphous, having a one-celled fruit (_Trichobasis_), as well as a two-celled fruit (_Puccinia_). The fungus which attacks the berberry is a species of cluster-cup (_Æcidium berberidis_), in which little cup-like peridia, containing bright orange pseudospores, are produced in tufts or clusters on the green leaves, together with their spermogonia.