Medical Offiers, of the Army of India.
Hay-Bacillus is checked just in proportion to the amount of the other species,
which is inoculated along with it, and the older any cultivation is and the more
the latter species comes to abound in it, the more do involution-forms of the
Hay-Bacillus tend to abound. Plate-cultivations, even from the oldest sources,
in which the Hay-Bacillus is at a minimum, fail to yield pure cultivations of the
other species, because when isolated from the former its elements do not find
the conditions necessary for their further development.
An example .of this kind illustrates, on the one hand, the favourable influence
which the presence of one species of Schizomycete may exert on the develop
- m e n t o f a n o t h e r , a n d o n t h e o t h e r h a n d t h e p o s s i b i l i t y o f t h e d e t e r m i n a t i o n . o f
obstruction or suppression of development under a similar association. In this
case the presence of the Hay-Bacillus determined the growth of the other spe
- c i e s , a n d t h e g r o w t h o f t h e l a t t e r o b s t r u c t e d t h e d e v e l o p m e n t o f i t s h o s t .
In the light of such facts, it becomes readily conceivable how variations in
the local conditions in any area of a nature to be quite inappreciable to ordinary
observation may determine the development or the extinction of organisms im
- p o r t e d i n t o i t , a n d t h e r e f o r e , i n c a s e s w h e r e t h e s e a r e o f p a t h o g e n i c n a t u r e , t h e
presence or absence of special forms of disease,
But variations in local conditions may tell in this direction in another
fashion also; they may not only determine the possibility of the existence of pa
- t h o g e n i c o r g a n i s m s i n t h e a r e a , t h e y m a y a l s o t e l l o n t h e i r c a p a c i t y f o r p r o d u c i n g
their specific effects on the organisms of the inhabitants. If we accept Koch's
theory of the epidemic diffusion of cholera, the essential coincident epidemic
diffusion of an abnormal dyspeptic condition may, quite conceivably, be due to
the presence of abnormal organisms in the affected localities.
View the question as we may, however, the paramount importance of local
conditions and the subordinate and secondary rôle which Comma-Bacilli must
play in reference to epidemic diffusion of cholera is very evident. The more
the facts are considered, the more evident does it become that no contagionist
theory will account for the phenomena of epidemic diffusion of the disease, and
that the only one which will do so must be of the nature of that which has been
so long advocated by the observer who has done most to advance our knowledge
of the subject. It is very possible to differ from Von Pettenkofer in regard to
matters of detail, and yet to believe that he has all along been in the right in
insisting on the primary importance of local conditions. It is of little moment
whether these. act by preventing or favouring the development of a germ, the
multiplication of a mature form, the presence of specially resistent elements, or
receptivity on the part of the inhabitants; in any case, they must be the primary
determinants, and those, too, which may be hopefully contended with. A soli
- t a r y l i v i n g B a c i l l u s , i m p o r t e d i n t o a f a v o u r a b l e l o c a l i t y , m a y , a s s u r e d l y , i f t h e
Schizomycete origin of cholera be a fact, give rise to an epidemic, and on purely
theoretical, as well as on practical grounds, the futility of measures aimed at pre-
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