especially indicated as the source of the superadded infective vegetation; and in many of the cases where the lungs are involved shortly after the commencement of the illness-an epiphenomenon which shows that the infection of pneumonia was taken in either simultaneously with or very soon after the infection of the other disease —the nature of this latter will frequently point to the bed as the common cause of the two concurrently induced affections. Many instances might be given, but brief notices of two outbreaks in schools must suffice.

In October 1885 Dr. Edward Seaton brought under notice a nondescript febrile epidemic which attacked the boys in a school suddenly and was in many cases complicated with pneumonia. The symptoms of the malady were strange and severe, but the point of interest here is, that a sudden fall of temperature in the cases was generally accompanied by the appearance of a peculiar herpetic eruption on the upper lip. The other outbreak in a school is the one that occurred during the present year (1888) at Glasgow; and, from the obscurity surrounding its causation, the singularity of the symptoms, and the rapidity of the deaths in the fatal cases, it received a deal of attention and was the subject of special investigation. Conclusions as to its etiology varied. Professor Gairdner inclined to regard the disease as malignant influenza; Dr. Finlayson took the outbreak to be one of epidemic or infectious pneumonia; whilst Dr. Gemmell looked on it as having a local origin and as not being of an epidemic type. Dr. Russell attributed the occurrence to the insanitary site of the school.

These peculiar outbreaks are of the highest etiological interest in many ways, but only one aspect of them can now be glanced at. They who shall have examined into the details will have observed, no doubt, that, as in the earlier so in this later outbreak, the boys attacked had herpes or herpetic affections. In its characters the disease in the one differed from that in the other school, but they were both accompanied more or less with pneumonia and herpes. And these links connect the two outbreaks in regard to origin. By the light of the "straw mildew theory" we may survey the causation of the diseases in the dormitories of the two schools, and we may see that the divergencies in their symptomatology were due to the intrusion of the spores of adventitious fungi into the ordinary kinds of bedroom malaria. The occurrence of herpes suggests the intervention of one of the Ustilagines or its allies; but speculation as to the class of the vegetation implicated in that feature would be unprofitable. It is enough if the view here opened out concerning the principal source and general nature of the infection by which the boys in the schools in question were affected shall be found to offer a fairly correct, though not literal, interpretation of the phenomena seen in these outbreaks. The appearance of peculiar eruptions during the course either of a normal or "true-bred" infective disease, or of an irregular or unclassified febrile disorder, points

significantly, if not conclusively, as has been before suggested, to the growth of some fungus (not commonly occurring in the sick-room) in close proximity to the sick; and the soil in the bed stands out as the place of growth. When, therefore, we find that herpes and pneumonia were associated with these school outbreaks, and weigh this fact with other data, the inference is that their infections derive from the same or from adjacent soil in or about the bed.

For the reasons very inadequately outlined in this short notice, I conceive that certainly all forms of epidemic pneumonia, and probably most instances of idiopathic pneumonia (for it would seem unlikely that congestions of the lung induced by cold pure and simple should lead to the lesions), are nearly related to measles. And when it is remembered that pneumonia is the most frequent, the earliest, and on the whole perhaps the gravest outcome of the attack of measles, it will be seen to be almost a certainty that the specific forms of vegetation which cause the lung affection and the rash are intermingled from the first and are taken into the organism together. In effect, in morbilli sine morbillis the catarrh and the pneumonia (with its attendant fever) constitute the disease; and the pneumonic symptoms might be held to be characteristic but for the occurrence of morbilli sine catarrho. Indeed, it is a warrantable assumption that epidemics of morbilli sine morbillis are, substantially, epidemics of pneumonia in which the "straw fungi" proper have been dropped out of the infection from some cause; and that in morbilli sine catarrho the converse happens. But as strict limitations in this respect rarely prevail throughout a district at epidemical seasons, all the local outbreaks, of whatever character, are classed as measles.

In short, I submit that the damp bed sufficiently accounts for at least nine-tenths of the occurrences of pneumonia; and that, therefore, all practical measures designed to prevent the disease will be effective in proportion to the number of beds they keep dry.

9. CATARRHS AND SORE THROATS.

The catarrhs and sore throats adolescents and adults get in a house in which children are down with measles are hardly congeners of measles, but are, rather, abortive attacks of the disease itself, of greater or less severity in proportion to the dose of the infection. They are instructive in that they exhibit what I take to be certain defects in the accepted theory of the causation of measles by contagium vivum, and in that they illustrate certain points in connection with the contention that measles cannot be communicated directly from person to person, either instantaneously or in any length of time, and that they are not to be caused except by a certain amount of exposure to what has been defined in this work to be efficient air-contamination: but as these points have been taken they need not be further dwelt upon.

10. WHOOPING COUGH.

If the "straw mildew theory" is sound, it is a certainty that whooping cough is a congener of measles. It may be difficult at present to conceive or to bring out the species of fungus concerned as the infective agent, but that it is one of the "straw fungi” proper or some species nearly allied to the "straw fungi" proper, or one which is addicted to, or will grow upon, the same or very similar descriptions of soil, there can be very little doubt. All the phenomena surrounding its incidence indicate that the bedroom is the place of infection, and that, almost as a necessary consequence, the bed is the site of the growth of the infective vegetation.

The markedly circumscribed localisation of the parasitism in the human body of the fungus which causes this affection-a localisation which has not yet been, I believe, determined by observation, but is to be inferred from its effects-denotes that a single entity only is concerned in causing the pathognomonic manifestations of the disease: yet the frequent occurrence of early pneumonia in whooping cough suggests that, as in measles, rötheln, scarlet fever, &c., the imbibition of the spores of the specific fungus is concurrent, or nearly so, with the introduction of the spores of other fungi growing, principally, about the bed. The not infrequent escape of the infant in arms from whooping cough also suggests the occurrence of the infective vegetation on the straw beds of the infected children; and, besides, disposes of the view as to the intensely contagious nature of the malady, unless it be held that young infants are endowed with preternatural insusceptibility, not only in regard to measles and scarlet fever, but to whooping cough and all infective diseases.

Several other phenomena would seem to stamp whooping cough as a congener of measles, rötheln, and scarlet fever, and therefore as a disease deriving from the "straw fungi." It is unknown, for instance, in the tropics, except among the white races. It is common in Japan, where it is known as the "Hundred Day Cough." Rötheln is also very common there, and appears in limited outbreaks; whilst measles are rare, and, as we have seen, occur only in extensive epidemics. From which it may be inferred, perhaps, that a less prolonged sodden state of the straw mats of the Japanese suffices for the germination and fruiting of the whooping cough and rötheln fungi than for the growth of the measles fungi-in such numbers and for such a length of time as to create efficient air-contamination. Whatever the precise explanation of these phenomena, however, the limitation of the occurrence of whooping cough to those regions in which measles and its congeners occur is significant as to their relationship. The alternation of these diseases, too—the following up of epidemics of measles by epidemics of whooping cough—is highly suggestive of the dying out of one crop of fungi and its supplantation

by another crop of allied fungi. Unlike the species which are assumed to cause pneumonia, these two species which are supposed respectively to cause measles and whooping cough would appear to want the same soil, or to be unable to grow side by side.

All things considered, the presumptive evidence is strong as to the existence of close relations between measles and whooping cough. It also lends colour to the view of the acclimatisation at different periods of their respective infective fungi on the artificial soil provided in straw beds. If this view is sound, it follows that the one disease cannot be stamped out without the other.

There may be a few more true congeners of measles, but this exhausts the list of those affections which appear to me to be obviously related to one another by way of the "straw fungi." I would submit, however, that it is more than probable that many other infective diseases have a common origin with them in the bed; and, moreover, that it is by no means unlikely that some diseases which do not originate in the bed are nevertheless fostered in it through an extension to the bedroom of their several infective fungi. Further, I suggest that it is almost a certainty that most diseases which entail confinement to bed for a month or six weeks may, if the under-bed be of straw, and cannot be or is not changed, be complicated by infective material alien to the diseases and derived chiefly from the bed; and that persons detained in bed under such conditions may be efficiently infected by the spores of the species of fungi which, collectively, induce pneumonia, and, perhaps, in addition, by the spores of the species which cause measles, or scarlet fever, or some other of their congeners which come of damp straw, and possibly also by the spores of the foreign or adventitious species which are assumed to find entrance into the paillasse and germinate there and cause peculiar eruptions.

II. INFLUENZA.

Although this disease clearly does not originate in "straw fungi," and as clearly does not depend on the bed of man, either for its occurrence or its spread, it is nevertheless a disease which so strongly resembles measles in some of its characteristics, that, but for its universal presence in a country, it would he impossible to discriminate between some local occurrences of influenza and certain types of measles. This likeness is perceptible even in the East, but by the time the waves of influenza have reached Europe it has become remarkable.

Influenza epidemics on the largest scale start in India or China as a widespread specific catarrh, and when at length the disease appears, say, in the British Isles, it would seem to acquire, or to have acquired, greater malignancy. Pathologists have not yet ascertained the precise nature of the infection, but looking at the principal seat and nature of the affection, it may safely be inferred that it is caused by the presence in the respiratory tract of the spores of fungi. What

fungus gives the chief specificity to the catarrh is not perhaps to be evolved; but putting together all the phenomena of a plague of influenza, it appears to me that, although one species, or perhaps one genus, stamps its effects on a large proportion of the infected, yet several species contribute to the sum of the infection. I conceive that the epidemic as a whole is the outcome of an inordinate growth, from rare seasonal conditions, of fungi of various kinds and in varying proportions in different countries and in different parts of the same country; the common moulds preponderating largely over all other fungi, in regard to the total number of spores contributed to the air. This undue growth of fungi extends over the surface of the land, and all available organic material is laid under contribution as soil; and as the whole atmosphere becomes charged with a much greater number of spores than the number man (or beast) can long breathe with impunity, the chances are that sooner or later most people succumb to the overwhelming invasion of the respiratory tract -the more especially if they expose themselves in the open at night, when the malaria, of course, holds the largest number of spores.

The activity of the facultative parasitism of the fungi inhaled will depend not only on the species taken in, and on their relative numbers in the total amount taken in, but also upon the soils upon which they have grown. There is but little doubt that the malaria of influenza is essentially an outdoor malaria. The advancing myriads of spores invade every particle of dead animal and vegetable matter lying about exposed to the air in the first place, and then send forward other swarming myriads to take possession of the unoccupied organic soils ahead. The severity of the epidemic in a given place will depend, therefore, in great measure, both on the quantity and on the quality of the organic matter distributed on its surface; or, in other words, will be proportionate to the degree of its general filth. But though the universally prevalent malaria is most potent, or causes more infections rather, outside habitations, particularly the dwellings of Europeans-inasmuch as it is shut out to some extent by walls, and dried (and therefore despoiled of many of its spores) by fires-yet in numbers of the bedrooms of a people the conditions will be highly favourable for the extension of the fungi. The persistently damp bedroom will afford these conditions, and the mattress and paillasse will always provide more or less congenial soil for the invading saprophytes. As a consequence the point of efficient air-contamination in such damp rooms will soon be reached, sooner than in the outer air; and in addition to the specific infective vegetation of influenza, the bedroom malaria thus created will hold the spores of whatever fungi are indigenous to the rooms, and are capable of growing side by side with the extraneous fungi. And among these would seem to be the "straw fungi" proper.

As the seasonal conditions which have preceded and accompanied the great epidemics of influenza in Europe are just such conditions as, when obtaining on a smaller scale, bring about epidemics of some

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