bservation, and during that period was held sacred from the
disturbing influences of the housemaid's broom and duster.

Curiosity prompted us from the first to submit the mouldy denizens of
the wall to the microscope, and this curiosity was increased week by
week, on finding that none of the forms found vegetating on nearly two
square yards of damp wall could be recognized as agreeing specifically
with any described moulds with which we were acquainted. Here was a
problem to be solved under the most favourable conditions, a forest of
mould indoors, within a few yards of the fireside, growing quite
naturally, and all strangers. Whence could these new forms proceed?

The cottony tufts of white mould, which were the first to appear, had
an abundant mycelium, but the erect threads which sprang from this
were for a long time sterile, and closely interlaced. At length
fertile threads were developed in tufts, mixed with the sterile
threads. These fruit-bearers were shorter and stouter, more sparingly
branched, but beset throughout nearly their whole length with short
patent, alternate branchlets. These latter were broadest towards the
apex, so as to be almost clavate, and the extremity was beset with two
or three short spicules. Each spicule was normally surmounted by an
obovate spore. The presence of fertile threads imparted the ochraceous
tint above alluded to. This tint was slight, and perhaps would not
have been noticed, but from the close proximity of the snow-white
tufts of barren threads. The fertile flocci were decumbent, probably
from the weight of the spores, and the tufts were a little elevated
above the surface of the matrix. This mould belonged clearly to the
_Mucedines_, but it hardly accorded well with any known genus,
although most intimately related to _Rhinotrichum_, in which it was
placed as _Rhinotrichum lanosum_.[R]

The white mould having become established for a week or two, small
blackish spots made their appearance on the paper, sometimes amongst
thin patches of the mould, and sometimes outside them. These spots, at
first cloudy and indefinite, varied in size, but were usually less
than a quarter of an inch in diameter. The varnish of the paper was
afterwards pushed off in little translucent flakes or scales, an
erect olivaceous mould appeared, and the patches extended to nearly an
inch in diameter, maintaining an almost universal circular form. This
new mould sometimes possessed a dirty reddish tint