Medical Officers of the Army of India.
17
attempting to diagnose any case of disease as of choleraic or non-choleraic nature
on the ground of the presence or absence of morphological vibriones in the
intestinal contents or in cultures derived from such sources. The choleraic
condition is certainly normally associated with an astonishing predominance
of vibrionic schizomycetes in the intestinal flora, but does not necessarily
imply that any corresponding predominance, or indeed any appreciable evi-
dence whatever, of the presence of morphological vibriones should be present.
In the majority of cases morphological vibriones are from the outset recognis-
able ; in a certain number they are potentially present, and only in a very few
exceptional cases do they seem to be both actually and potentially absent.
Until quite recently, I was inclined to regard the normal association of
intestinal vibriones with cholera as a purely fortuitous phenomenon, solely deter-
mined by the fact that the abnormal condition of the intestinal contents, accom-
panying the onset of the disease, afforded a favourable environment to
schizomycetes of certain kinds, and especially to members of the vibrionic group
of such organisms. The mere fact that species of vibrio do, as a rule, abound
so excessively in choleraic materials, implies the fact that the latter constitute a
highly favourable environment for their continued vitality and indefinite multi-
plication ; but the mass of evidence accumulated by the labours of von Pettenkofer
and other epidemiologists, and the data derived from the history of cholera in
the hospitals of Calcutta and from the practical results of " camping out " of
bodies of troops or prisoners in all parts of India, appeared so conclusively to
demonstrate that the introduction of choleraic patients and, therefore, of large
quantities of choleraic vibriones into a locality, is by no means necessarily any
source of immediate danger to the latter, that there appeared to be good ground
to doubt whether there were any causal relation whatever between choleraic
vibriones and the disease, and whether the association of the former with the latter
ought not to be regarded as merely consequential rather than of causal origin.
The data were such as seemed to render it possible to account for the peculiari-
ties of the choleraic intestinal flora on the hypothesis that they were simply the
result of the action of the abnormal conditions of the intestinal fluids, in the cho-
leraic state, on the schizomycete population of the intestinal tract ; for it is per-
fectly evident that, with such a formidable alteration in the nature of the
intestinal fluids (looked on as an environment), as the establishment of the
choleraic condition implies, there must tend to be an equally considerable altera-
tion in the nature of the intestinal schizomycete population. Under normal
circumstances, the intestinal contents represent an environment of certain definite
properties, and the latter must necessarily determine what the nature of the pre-
dominant schizomycete population will be ; but, if the properties of the environ-
ment be suddenly and very essentially altered, it almost necessarily follows that a
corresponding alteration in the nature of the population must ensue. The normal
intestinal flora represents the outcome of a struggle for existence under one set of D