Medical Officers of the Army of India.
33
A comparison of the above notes shows clearly that, in spite of prolonged
exposure to the influence of cultivation under like conditions, certain forms of
comma-bacilli occurring in connection with cholera in Calcutta continue to
show distinctive peculiarities. In certain cases, such as those of forms δ , ι , and
λ , these are so very conspicuous that it is almost impossible to imagine that
any unprejudiced observer can regard them as indicative of any but specific
differences. But even in regard to the others, I believe that the distinctions;
although minor in degree as compared with those present in the above cases,
are really of specific value, for in no single case has there been any true unification
in character between any two forms. Certain distinctive peculiarities, which were
primarily very conspicuous, have in some cases diminished or even totally dis-
appeared under the influence of prolonged cultivation, but only to be replaced
by new ones, and we have therefore no ground to believe that any general true
assimilation in character has occurred. But if this be so in a case where we are
dealing with organisms which, as even the data contained in the preceding pages
unequivocally show, are specially liable to modification under the influences of
alterations in environment, we have certainly no ground for regarding the differen-
ces which they present as the result of mere variations incident on exposure to
special conditions, and I, therefore, can only once more affirm that not only do a
certain number of cases of cholera, or, at all events of disease presenting all the
symptoms of cholera, occur in Calcutta unaccompanied by the presence of any
cultivable comma-bacilli whatever, but that in those cases in which such organisms
are present, they are neither necessarily of the nature of those described by Koch
nor of any one particular species. But, if cases of the disease can occur apart
from the presence of any cultivable comma-bacilli within the digestive tract of,
or in association with, the presence of many very distinct cultivable species, it is
clear that Koch's theory that the symptoms are due to the action of a particular
species of such organisms, and epidemic diffusion of the disease to its conveyance
from one locality to another by means of human intercourse is untenable.
Whilst this is the case, it of course does not necessarily follow that the
disease is not due to the presence of certain organisms within the intestinal tract.
The evidence unequivocally forbids the assumption that it is invariably due to
the presence of the bacillus described by Koch or to that of any other specific
organism which has hitherto been isolated, but it may be argued that the fact
that the vast majority of cases of the disease are characterised by the presence
of comma-bacilli of one form or other, affords good ground for believing that
although not specifically related to the access of any one individual species of
schizomycetes to the digestive tract, the disease is due to the access of any
member of a group of schizomycetes possessing certain peculiarities in respect
to the nature of the products which they give rise to during the course of their
development, and that the commonest members of this group are certain species
of comma-bacilli. The objection to this view lies first in the absence of any
F