estructive silk-worm disease, _Botrytis Bassiana_, is also a
fungus which attacks and destroys the living insect, concerning which
an immense deal has been written, but which has not yet been
eradicated. It has also been supposed that a low form or imperfect
condition of a mould has much to do with the disease of bees known as
"foul brood."[S]

_Penicillium Fieberi_, figured by Corda on a beetle, was doubtless
developed entirely after death, with which event it had probably
nothing whatever to do.[T] Sufficient, however, has been written to
show that fungi have an influence on insect life, and this might
be extended to other animal forms, as to spiders, on which one or two
species of _Isaria_ are developed, whilst Dr. Leidy has recorded
observations on _Julus_[U] which may be perused with advantage.
Fish are subject to a mouldy-looking parasite belonging to the
_Saprolegniei_, and a similar form attacks the ova of toads and
frogs. Gold fish in globes and aquaria are very subject to attack
from this mouldy enemy, and although we have seen them recover
under a constant change of water, this is by no means always the
case, for in a few weeks the parasite will usually prevail.

The influence of fungi upon animals in countries other than
European is very little known, except in the case of the species of
_Torrubia_ found on insects, and the diseases to which silkworms are
subject. Instances have been recorded of the occurrence of fungoid
mycelium--for in most it is nothing more--in the tissues of
animals, in the hard structure of bone and shell, in the intestines,
lungs, and other fleshy parts, and in various organs of birds.[V] In
some of the latter cases it has been described as a Mucor, in most it
is merely cells without sufficient character for determination. It is
by no means improbable that fungi may be found in such situations;
the only question with regard to them is whether they are not
accidental, and not the producers of unhealthy or diseased tissues,
even when found in proximity thereto.

There is one phase of the influences of fungi on the lower animals
which must not be wholly passed over, and that is the relation which
they bear to some of the insect tribes in furnishing them with food.
It is especially the case with the _Coleoptera_ that many species seem
to be entirely dependent on fungi for existence, since they are found
in no other situations. Beetle-hunters tell us that old _Polyporei_,
and similar f