time one of the most beautiful. This is the _Agaricus muscarius_, or
Fly Agaric, which is sometimes used as a fly poison.[A] It has a
bright crimson pileus studded with pale whitish (sometimes yellowish)
warts, and a stem and gills of ivory whiteness. Many instances have
been recorded of poisoning by this fungus, and amongst them some
British soldiers abroad, and yet it cannot be doubted that this fungus
is eaten in Russia. Two instances have come under our notice of
persons with some botanical knowledge, and one a gardener, who had
resided in Russia and eaten of this fungus. In one case the Fly Agaric
was collected and shown to us, and in the other the figure was
indicated, so that we might be under no doubt as to the species. Only
one hypothesis can be advanced in explanation. It is known that a
large number of fungi are eaten in Russia, and that they enter much
into the domestic cookery of the peasantry, but it is also known that
they pay considerable attention to the mode of cooking, and add a
large amount of salt and vinegar, both of which, with long boiling,
must be powerful agents in counteracting the poison (probably somewhat
volatile) of such fungi as the Fly Agaric. In this place we may give a
recipe published by a French author of a process for rendering
poisonous fungi edible. It must be taken on his authority, and not our
own, as we have never made the experiment, notwithstanding it seems
somewhat feasible:--For each pound of mushrooms, cut into moderately
small pieces, take a quart of water acidulated with two or three
spoonfuls of vinegar, or two spoonfuls of bay salt. Leave the
mushrooms to macerate in the liquid for two hours, then wash them with
plenty of water; this done, put them in cold water and make them boil.
After a quarter or half hour's boiling take them off and wash them,
then drain, and prepare them either as a special dish, or use them for
seasoning in the same manner as other species.[B]
This method is said to have been tried successfully with some of the
most dangerous kinds. Of these may be mentioned the emetic mushroom,
_Russula emetica_, with a bright red pileus and white gills, which
has a clear, waxy, tempting appearance, but which is so virulent that
a small portion is sufficient to produce disagreeable consequences. It
would be safer to eschew all fungi with a red or crimson pileus than
to run the risk of indulging in this. A white species, which, however,
is not very common, with a bulbous base enclosed in a volva, called
_Agaricus vernus_, should also be avoided. The pink spored species
should also be regarded with suspicion. Of the _Boleti_ several turn
blue when cut or broken, and these again require to be discarded. This
is especially the case with _Boletus luridus_[C] and _Boletus
Satanas_,[D] two species which have the under surface or orifice of
the pores of a vermilion or blood-red colour.
Not only are species which are known to be poisonous to be avoided,
but discretion should be used in eating recognized good species. Fungi
undergo chemical changes so rapidly that even the cultivated mushroom
may cause inconvenience if kept so long after being gathered as to
undergo chemical change. It is not enough that they should be of a
good kind, but also fresh. The employment of plenty of salt in their
preparation is calculated very much to neutralize any deleterious
property. Salt, pepper, and vinegar are much more freely employed
abroad in preparing fungi than with us, and with manifest advantage.
It is undoubtedly true that fungi exert an important influence in
skin diseases. This seems to be admitted on all hands by medical
men,[E] however much they may differ on the question of the extent to
which they are the cause or consequence of disease. Facts generally
seem to bear out the opinion that a great number of skin diseases
are aggravated, and even produced, by fungi. Robin[F] insists that a
peculiar soil is necessary, and Dr. Fox says it is usually taught
that tuberculous, scrofulous, and dirty people furnish the best
nidus. It is scarcely necessary to enumerate all these diseases,
with which medical men are familiar, but simply to indicate a few.
There is favus or scall-head, called also "porrigo," which has its
primary seat in the hair follicles. Plica polonica, which is
endemic in Russia, is almost cosmopolitan. Then there is Tinea
tonsurans, Alopecia, Sycosis, &c., and in India a more deeply-seated
disease, the Madura Foot, has been traced to the ravages of a fungus
described under the name of _Chionyphe Carteri_.[G] It is probable
that the application of different names to the very often imperfect
forms of fungi which are associated with different diseases is not
scientifically tenable. Perhaps one or two common moulds, such as
_Aspergillus_ or _Penicillium_, lie at the base of the majority, but
this is of little importance here, and does not affect the general
principle that some skin diseases are due to fungi.
Whilst admitting that there are such diseases, it must be understood
that diseases have been attributed to fungi as a primary cause, when
the evidence does not warrant such a conclusion. Diphtheria and thrush
have been referred to the devastations of fungi, whereas diphtheria
certainly may and does occur without any trace of fungi. Fevers may
sometimes be accompanied by fungoid bodies in the evacuations, but it
is very difficult to determine them. The whole question of epidemic
diseases being caused by the presence of fungi seems based on most
incomplete evidence. Dr. Salisbury was of opinion that camp measles
was produced by _Puccinia graminis_, the pseudospores of which
germinated in the damp straw, disseminated the resultant secondary
bodies in the air, and caused the disease. This has never been
verified. Measles, too, has been attributed freely, as well as
scarlatina,[H] to fungal influences, and the endeavours to implicate
fungi in being the cause of cholera have been pertinaciously
persevered in with no conviction. The presence of certain cysts, said
to be those of _Urocystis_, derived from rice, was announced by Dr.
Hallier, but when it was shown that no such fungus was found on rice,
this phase of the theory collapsed. Special and competent experts were
sent from this country to examine the preparations and hear the
explanations of Dr. Hallier on his theory of cholera contagion, but
they were neither convinced nor satisfied.
As long ago as 1853, Dr. Lauder Lindsay examined and reported on
cholera evacuations, and in 1856 he declared--"It will be evident that
I can see no satisfactory groundwork for the fungus theory of cholera,
which I am not a little surprised to find still possesses powerful
advocates."[I] And of the examinations undertaken by him he
writes:--"The mycelium and sporules of various species of fungi,
constituting various forms of vegetable mould, were found in the scum
of the vomit, as well as of the stools, but only at some stage of
decomposition. They are found, however, under similar circumstances,
in the vomit and stools of other diseases, and, indeed, in all
decomposing animal fluids, and they are therefore far from peculiar to
cholera."
Some writers have held that the atmosphere is often highly charged
with fungi spores, others have denied the presence of organic bodies
to any extent in the air. The experiments conducted in India by Dr.
Cunningham[J] have been convincing enough on this point. This report
states that spores and similar cells were of constant occurrence, and
were generally present in considerable numbers. That the majority of
the cells were living and ready to undergo development on meeting with
suitable conditions was very manifest, as in those cases in which
preparations were retained under observation for any length of time,
germination rapidly took place in many of the cells; indeed, many
spores already germinating were deposited on the slides. In few
instances did any development take place beyond the formation of
mycelium or masses of toruloid cells, but in one or two distinct
sporules were developed on the filaments arising from some of the
larger septate spores, and in a few others _Penicillium_ and
_Aspergillus_ produced their characteristic heads of fructification.
With regard to the precise nature of the spores and other cells
present in various instances little can be said, as, unless their
development were to be carefully followed out through all its stages,
it is impossible to refer them to their correct species or even
genera. The greater number of them are apparently referable to the old
orders of fungi--_Sphæronemei_, _Melanconei_, _Torulacei_, _Dematiei_,
and _Mucedines_, while some probably belonged to the _Pucciniei_ and
_Coæmacei_. Amongst those belonging to the _Torulacei_, the most
interesting was a representative of the rare genus _Tetraploa_.
Distinct green algoid cells occurred in some specimens. Then follow in
the report details of observations made on the rise and fall of
diseases, of which diarrhoea, dysentery, cholera, ague, and dengue
were selected and compared with the increase or diminution of
atmospheric cells. The conclusions arrived at are:--
"Spores and other vegetable cells are constantly present in
atmospheric dust, and usually occur in considerable numbers; the
majority of them are living, and capable of growth and development.
The amount of them present in the air appears to be independent of
conditions of velocity and direction of the wind, and their number is
not diminished by moisture.
"No connection can be traced between the numbers of bacteria, spores,
&c., present in the air, and the occurrence of diarrhoea, dysentery,
cholera, ague, or dengue, nor between the presence or abundance of any
special form or forms of cells, and the prevalence of any of these
diseases.
"The amount of inorganic and amorphous particles and other débris
suspended in the atmosphere is directly dependent on conditions of
moisture and velocity of wind."
This report is accompanied by fourteen large and well-executed plates,
each containing hundreds of figures of organic bodies collected from
the air between February and September. It is valuable both for its
evidence as to the number and character of the spores in the air, and
also for the tables showing the relation between five forms of
disease, and their fluctuations, as compared with the amount of spores
floating in the atmosphere.
We are fain to believe that we have represented the influence of fungi
on man as far as evidence seems to warrant. The presence of forms of
mould in some of their incipient conditions in different diseased
parts of the human body, externally and internally, may be admitted
without the assumption that they are in any manner the cause of the
diseased tissues, except in such cases as we have indicated. Hospital
gangrene may be alluded to in this connection, and it is possible that
it may be due to some fungus allied to the crimson spots (blood rain)
which occur on decayed vegetation and meat in an incipient stage of
decomposition. This fungus was at one time regarded as an algal, at
another as animal; but it is much more probable that it is a low
condition of some common mould. The readiness with which the spores of
fungi floating in the atmosphere adhere to and establish themselves on
all putrid or corrupt substances is manifest in the experience of all
who have had to do with the dressing of wounds, and in this case it is
a matter of the greatest importance that, as much as possible,
atmospherical contact should be avoided.
Recently a case occurred at the Botanic Gardens at Edinburgh which was
somewhat novel. The assistant to the botanical professor was preparing
for demonstration some dried specimens of a large puff-ball, filled
with the dust-like spores, which he accidentally inhaled, and was for
some time confined to his room under medical attendance from the
irritation they caused. This would seem to prove that the spores of
some fungi are liable, when inhaled in large quantities, to derange
the system and become dangerous; but under usual and natural
conditions such spores are not likely to be present in the atmosphere
in sufficient quantity to cause inconvenience. In the autumn a very
large number of basidiospores must be present in the atmosphere of
woods, and yet there is no reason to believe that it is more unhealthy
to breathe the atmosphere of a wood in September or October than in
January or May. Dreadful effects are said to be produced by a species
of black rust which attacks the large South of Europe reed, _Arundo
donax_. This is in all probability the same species with that which
attacks _Arundo phragmitis_ in this country, the spores of which
produce violent headaches and other disorders amongst the labourers
who cut the reeds for thatching. M. Michel states that the spores from
the parasite on _Arundo donax_, either inhaled or injected, produce
violent papular eruption on the face, attended with great swelling,
and a variety of alarming symptoms which it is unnecessary to
particularize, in various parts of the body.[K] Perhaps if _Sarcina_
should ultimately prove to be a fungus, it may be added to the list of
those which aggravate, if they are not the primary cause of, disease
in the human subject.
II. What influences can be attributed to fungi upon animals other than
man? Clearly instinct preserves animals from many dangers. It may be
presumed that under ordinary circumstances there is not much fear of a
cow or a sheep poisoning itself in a pasture or a wood. But under
extraordinary circumstances it is not only possible, but very
probable, that injuries may occur. For instance, it is well known that
not only rye and wheat, but also many of the grasses, are liable to
infection from a peculiar form of fungus called "ergot." In certain
seasons this ergot is much more common than others, and the belief is
strong in those who ought to know something of the subject from
experience, viz., farmers and graziers, that in such seasons it is not
uncommon for cattle to slip their young through feeding on ergotized
grass. Then, again, it is fairly open to inquiry whether, in years
when "red rust" and "mildew" are more than usually plentiful on
grasses, these may not be to a certain extent injurious. Without
attempting to associate the cattle plague in any way with fungi on
grass, it is nevertheless a most remarkable coincidence that the year
in which the cattle disease was most prevalent in this country was one
in which there was--at least in some districts--more "red rust" on
grasses than we ever remember to have seen before or since; the
clothes of a person walking through the rusty field soon became
orange-coloured from the abundance of spores. Graziers on this point
again seem to be generally agreed, that they do not think "red rust"
has been proved to be injurious to cattle. The direct influence of
fungi on quadrupeds, birds, reptilia, &c., seems to be infinitesimally
small.
Insects of various orders have been observed from time to time to
become the prey of fungi.[L] That known at Guadaloupe under the name
of _La Guêpe Végétale_, or vegetable wasp, has been often cited as
evidence that, in some instances at least, the fungus attacks the
insect whilst still living. Dr. Madianna states that he has noticed
the wasp still living with its incumbrance attached to it, though
apparently in the last stage of existence, and seeming about to perish
from the influence of its destructive parasite.[M] This fungus is
called by Tulasne _Torrubia sphecocephala_.[N] About twenty-five
species of this genus of sphæriaceous fungi have been described as
parasitic on insects. Five species are recorded in South Carolina, one
in Pennsylvania, found on the larvæ of the May-bug, and one other
North American species on Nocturnal Lepidoptera, one in Cayenne, one
in Brazil, on the larva of a _Cicada_, and one on a species of ant,
two in the West Indies, one in New Guinea on a species of _Coccus_,
and one on a species of _Vespa_ in Senegal. In Australia two species
have been recorded, and two are natives of New Zealand. Dr. Hooker
found two in the Khassya mountains of India, and one American species
has also been found at Darjeeling. It has long been known that one
species, which has a medicinal repute there, is found in China, whilst
three have been recorded in Great Britain. Opinions are divided as to
whether in these instances the fungus causes or is subsequent to the
death of the insect. It is generally the belief of entomologists that
the death of the insect is caused by the fungus. In the case of
_Isaria sphingum_, which is the conidia form of a species of
_Torrubia_, the moth has been found standing on a leaf, as during
life, with the fungus sprouting from its body.
Other and less perfect forms of fungi also attack insects. During the
summer of 1826, Professor Sebert collected a great many caterpillars
of _Arctia villica_, for the purpose of watching their growth. These
insects on arriving at their full size became quite soft, and then
suddenly died. Soon after they became hard, and, if bent, would easily
break into two pieces. Their bodies were covered with a beautiful
shining white mould. If some of the caterpillars affected with the
parasitic mould were placed on the same tree with those apparently
free from its attack, the latter soon exhibited signs that they also
were attacked in the same manner, in consequence of coming into
contact with each other.[O]
During the spring of 1851, some twelve or twenty specimens were found
from amongst myriads of _Cicada septemdecim_, which, though living,
had the posterior third of the abdominal contents converted into a
dry, powdery, ochreous-yellow compact mass of sporuloid bodies. The
outer coverings of that portion of the insect were loose and easily
detached, leaving the fungoid matter in the form of a cone affixed by
its base to the unaffected part of the abdomen of the insect. The
fungus may commence, says Dr. Leidy, its attacks upon the larva,
develop its mycelium, and produce a sporular mass within the active
pupa, when many are probably destroyed; but should some be only
affected so far as not to destroy the organs immediately essential to
life, they might undergo their metamorphosis into the imago, in which
case they would be affected in the manner previously described.[P]
The common house-fly in autumn is very usually subject to the attacks
of a mouldy fungus called _Sporendonema muscæ_, or _Empusa muscæ_ in
former times, which is now regarded as the terrestrial condition of
one of the _Saprolegniei_.[Q] The flies become sluggish, and at last
fix themselves to some object on which they die, with their legs
extended and head depressed, the body and wings soon becoming covered
with a minute white mould, the joints of which fall on the surrounding
object. Examples are readily distinguished when they settle on windows
and thus succumb to their foe. Mr. Gray says that a similar mould has
been observed on individuals of the wasp family.
A _Gryllotalpa_ was found in a wood near Newark, Delaware, U. S., upon
turning over a log. The insect was seen standing very quietly at the
mouth of its oval cell, which is formed in the earth, having a short
curved tube to the surface. Upon taking it up it exhibited no signs of
movement, though perfectly fresh and lifelike in appearance. On
examining it next morning it still presented no signs of life. Every
part of the insect was perfect, not even the antennæ being broken.
Upon feeling it, it was very hard and resistant, and on making an
incision through the thorax it exhaled a fungoid odour. The insect had
been invaded by a parasitic fungus which everywhere filled the animal,
occupying the position of all the soft tissue, and extending even into
the tarsal joints. It formed a yellowish or cream-coloured compact
mass.[R]
The destructive 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 fungi of a corky or woody nature, are always sought after
for certain species which they seek in vain elsewhere,[W] and those
who possess herbaria know how destructive certain minute members of
the animal kingdom are to their choicest specimens, against whose
depredations even poison is sometimes unavailing.
Some of the Uredines, as _Trichobasis suaveolens_ and _Coleosporium
sonchi_, are generally accompanied by a little orange larva which
preys upon the fungus; and in the United States Dr. Bolles informs us
that some species of _Æcidium_ are so constantly infested with this
red larva that it is scarcely possible to get a good specimen, or to
keep it from its sworn enemy. Minute _Anguillidæ_ revel in tufts of
mould, and fleshy Agarics, as they pass into decay, become colonies of
insect life. Small _Lepidoptera_, belonging to the _Tineina_, appear
to have a liking for such _Polyporei_ as _P. sulfureus_ when it
becomes dry and hard, or _P. squamosus_ when it has attained a similar
condition. _Acari_ and _Psocidæ_ attack dried fungi of all kinds, and
speedily reduce them to an unrecognizable powder.
III. What are the influences exerted by fungi on other plants? This is
a broad subject, but withal an important one, since these influences
act indirectly on man as well as on the lower animals. On man,
inasmuch as it interferes with the vegetable portion of his food,
either by checking its production or depreciating its quality. On the
lower animals, since by this means not only is their natural food
deteriorated or diminished, but through it injurious effects are
liable to be produced by the introduction of minute fungi into the
system. These remarks apply mainly to fungi which are parasitic on
living plants. On the other hand, the influence of fungi must not be
lost sight of as the scavengers of nature when dealing with dead and
decaying vegetable matter. Therefore, as in other instances, we have
here also good and bad influences intermingled, so that it cannot be
said that they are wholly evil, or unmixed good.