Fungi: Their Nature and Uses

by M. C. Cooke

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 diarrhœa, 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 diarrhœa, 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.