diate influence is greater than has been generally suspected.
Dr. Lowe has induced sldu-diseases by inoculation with the
grannies of yeast, and he is inclined to attribute a great deal
more to the agency of Fungi than has hitherto been allowed.*
An exact knowledge of their influence, whether externally or
internally, meanwhile, is producing a better mode of treatment,
such salts being administered with good effect as are
fatal to fungal growth.
Fungi, perhaps, are more destructive to insects than to
other members of the animal kingdom. Several species of
the genus Cordiceps, as (Plate 23, fig. 4, 5) C. militaris and
entomorrhiza, attack insects in the pupa or larva state, and,
as it should seem, while they are still living. The insect-
plant of New Zealand, which is so often brought home by
travellers, is a familiar example. One species, indeed, in the
West Indies, is developed on a perfect wasp, which flies about
with it, till it is weighed down by its Sindbad, and dies. The
fact was stated many years ago, and obtained but little credence
; hut I am assured by one who has had an opportunity
of ascertaining the real state of the case, that it is strictly
true. Silkworms suffer from a disease called Mnscardine,
from its converting them into a hard substance resembling a
particular kind of pastile, and at the time of their death have
their tissues completely traversed by the spawn of a Botrytis.
A few spores placed lightly on the skin are sufficient to propagate
the disease. Bees also, it is believed, occasionally die
from a similar cause, but this requires confirmation.
I t would be easy to multiply instances, were it necessary,
hut these are sufficient for my purpose. The diseases produced
by Fungi amongst vegetables are far more formidable
from the injury they cause in those plants which supply the
* See ‘ Lancet,’ Sept. 17, 1859.
staple food of man. Most of the Fungi which attack living
vegetables belong to the lower Orders of the tribe. The
spaw'n, however, of higher species is often fatal to trees and
herbaceous plants, by running over the roots and inducing
decay. I t has been long known that trees would not in general
flourish where others had grown before, and this was
attributed to exhaustion of the soil; it is now, however, ascertained
that the evil arises from spawn attached to old decaying
roots. A most striking instance occurred lately in the
Gardens at Kew. Two Deodaras were planted before the director’s
house, within a few yards of each other, under apparently
similar circumstances. After a time, one of these
became unhealthy, and it was suggested that the roots should
he examined. A scrutiny in consequence took place, when it
was found that an old cherry-tree formerly stood on the
same spot, that its roots were covered with spawn, and that
this had extended to the roots of the Deodara. The remains
of the old cherry-tree were accordingly grubbed up, and the
diseased portions of the Deodara removed, and now it bids
fair to thrive without any further check. The effect is sometimes
apparently so sudden, that it is attributed to lightning,
the fact being that the exigencies of the plant have been supplied
by a small portion of the roots which remained in a
sufficiently healthy condition to convey nutriment. Herbaceous
plants—as, for instance, strawberries—suffer from the
same cause, and it is now matter of certainty, that wherever
fragments of wood or sticks exist in manure, whether
in the garden or field, there is considerable danger. The
formidable Larch-rot, which converts the trunks of larches
so frequently into hollow pipes, is often attributable to this
cause.
Several Fungi, as Polyporus squamosus, and other species.