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S c i e n t i f i c M e m o i r s b y
a tendency to an increase in size of the individual commas connected with
transference to a less nutritive medium, the conditions appearing in one case to
make for rapid multiplication, in the other for continued growth, of individuals.
There can be little doubt that the persistence of the commas in the case of
the heated media must be regarded as due to the artificial advantage which they
there acquired in the struggle for existence. The temperature was not sufficient
to produce any important change in the water or soil, save reducing the number
of living organisms in them. In regard to the mixture of soil and fæculent
matter, it is easy to realise so far exactly why such a reduction should have been
of advantage to the commas. The change which primarily takes place in con
-nection with decomposing fæculence of normal quality in Calcutta is an exces
-sive development of filamentous fungi, which is accompanied by extreme acidity
and a temporary suppression of schizomycete evolution generally, and, from
what we know of the nature of the comma-bacilli, such conditions must be espe
-cially unfavourable to them. In the case of the water, however, there is no such
development of filamentous fungi present, so that the boiling here must have
acted in some other fashion. It seems probable that here also it was the partial
sterilisation that was the efficient factor, due to its destructive effects on the
schizomycetes normally present. The removal of these was calculated to favour
the commas in the struggle for existence, certainly by increasing the amount of
food at their disposal, and also, quite possibly, by arresting the formation of
waste products, arising in connection with the development of other forms and
directly toxic in their effects on the commas. In the case of the soil the effect
would not be limited to the suppression of the higher fungi, but would also par
-tially extend to the schizomycetes originally present in it and the fæculence with
which it was mingled; and, although actual sterilisation was not attained, must
have destroyed large numbers of them and may have determined the absence of
species specially antagonistic to the commas.
In the discussion of the vexed question of the relation of Comma-Bacilli
to cholera generally, it would appear to have been very commonly assumed that,
in order to a definite decision of it, all that was necessary was to show that
choleraic symptoms accompanied the multiplication of commas within the
intestinal tract, or the introduction of special toxic matters of the nature of
ptomaines formed by them into the system, by that or other paths. Great dili
- g e n c e h a s t h e r e f o r e b e e n a p p l i e d t o e x p e r i m e n t a l r e s e a r c h i n t h i s d i r e c t i o n , a n d
the fact that morbid effects are frequently the result has, by those who regard
these as of truly choleraic character, been regarded as a final one, while
another school of observers has devoted all its energies to endeavour to show
that the symptoms are not really choleraic in their nature. It appears to have
been, to a great extent at all events, lost sight of that there are really two subor
- d i n a t e q u e s t i o n s i n v o l v e d i n t h e m a j o r o n e o f t h e r e l a t i o n o f t h e B a c i l l u s t o t h e
disease. These are first:—Are commas or their products capable of giving