, but was commonly
dark olive. There could be no mistake about the genus to which this
mould belonged; it had all the essential characters of _Penicillium_.
Erect jointed threads, branched in the upper portion in a fasciculate
manner, and bearing long beaded threads of spores, which formed a
tassel-like head, at the apex of each fertile thread. Although at
first reminded of _Penicillium olivaceum_, of Corda, by the colour of
this species, it was found to differ in the spores being oblong
instead of globose, and the ramifications of the flocci were
different. Unable again to find a described species of _Penicillium_
with which this new mould would agree, it was described under the name
of _Penicillium chartarum_.[S]

Almost simultaneously, or but shortly after the perfection of the
spores of _Penicillium_, other and very similar patches appeared,
distinguished by the naked eye more particularly by their dendritic
form. This peculiarity seemed to result from the dwarfed habit of the
third fungus, since the varnish, though cracked and raised, was not
cast off, but remained in small angular fragments, giving to the spots
their dendritic appearance, the dark spores of the fungus protruding
through the fissures. This same mould was also found in many cases
growing in the same spots amongst _Penicillium chartarum_, but whether
from the same mycelium could not be determined.

The distinguishing features of this fungus consist in an extensive
mycelium of delicate threads, from which arise numerous erect
branches, bearing at the apex dark brown opaque spores. Sometimes the
branches were again shortly branched, but in the majority of instances
were single. The septate spores had from two to four divisions, many
of them divided again by cross septa in the longitudinal direction of
the spore, so as to impart a muriform appearance. As far as the
structure and appearance of the spores are concerned, they resembled
those of _Sporidesmium polymorphum_, under which name specimens were
at first published,[T] but this determination was not satisfactory.
The mycelium and erect threads are much too highly developed for a
good species of _Sporidesmium_, although the name of _Sporidesmium
alternaria_ was afterwards adopted. In fresh specimens of this fungus,
when seen _in situ_ by a half-inch objective, the spores appear to be
moniliform, but if so, all attempts to see them so connected, when
separated from the matrix, failed. On one occasio