Medical Officers of the Army of India.

17

rôle indeed in so far as epidemics are concerned. If Hueppe's observations be
accepted the subordination would, of course, not be so great, but it would still
be present, as it would still be necessary that the local conditions should be
adapted to allow of the multiplication of the Bacilli and of the development of
Arthrospores from them. In both cases alike it would be the presence of abnor-
mal local conditions, and not mere importation of commas, that would be the
primary determinant of epidemic occurrence of the disease, and the preven-
tion of the development of such local conditions would be the end to be aimed
at in the endeavour to prevent such an occurrence.

     As we have already seen, the deviations from the normal tending to favour
the establishment of the Bacilli must probably lie either in increase of suitable
nutritive supply, or in the lowering of the struggle for existence with other
organisms, and the practical measures to avoid the establishment must there-
fore be aimed either at diminution of supply of suitable nutritive material or the
increase of the struggle for existence. The former aim will certainly be more
or less attained by improvements in local sanitation tending to increased purity
of soil and water, the latter would no doubt be to some extent achieved by the
same method, for diminished nutritive supply in itself implies increased struggle
but could only be satisfactorily arrived at by means of an accurate acquaint-
ance with the nature of the organisms most inimical to the Bacilli. Even
could such information be attained there can be no doubt that the endeavour
to diminish nutritive supply would be the preferable course to follow, as it by
no means would necessarily follow that the organisms which were inimical to Com-
ma-Bacilli should be innocent or desirable inhabitants of a locality. As Naegel
long ago pointed out, ¹it is quite possible that excessive dirt in a locality may
be an efficient cause for the prevention of the prevalence of certain forms of
disease in it, the excess of saprophytic organisms tending to the suppression of
more or less parasitic ones, but no one could regard it as, therefore, desirable to
increase the accumulation of dirt.

     It is worth while to consider the principal ways in which the struggle for exist-
ence to which the Comma-Bacilli are exposed in any locality to which they gain
access might be diminished. It might be diminished simply as a result
of diminution in the number of conflicting organisms generally, the nutritive
supply remaining at the same time unaltered. The greater the diminution was
the more would the locality come to resemble a sterilised medium in its relation
to the Comma-Bacilli. Diminution might also be dependent, not on mere general
decrease in the number of organisms present, but on special decrease or
disappearance of organisms specially inimical to Comma-Bacilli, either directly
or indirectly by means of their products. Thirdly, it might be dependent on the
presence of organisms which, in place of being mere competitors for nutrition
or directly inimical, were positively favourable to their development.

     ¹Nägeli, C.v., Die niederen Pilze in ihren Beziehungen zu den Infectionskrankheiten und der Gesundheits-
pflege. München und Leipzig—R. Oldenburg, 1887.

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