Medical Officers of the Army of India .
7
the course of a few days proved fatal to all of them but one. This one was
removed to another basin and is still alive and healthy up to the present time—
more than a year later. A cultivation of the intestinal contents of one of the.
dead fish was first established in a tube of agar-agar medium, and primary
growth which appeared in this was employed as the source for a plate-culture.
Twenty-four hours after the latter had been set, it was found to be crowded
with superficial and interstitial colonies which, apparently, were all alike in
regard to the nature of their constituent elements. The superficial colonies
were ochreous, roughly granular in texture and of very dense consistence,
resisting diffusion even under rough friction. The smell of the culture
was fishy. When treated with 33 per cent. nitric acid the colonies very
slowly acquired a faint pink tinge. The constituent elements entering into
their composition were well-curved comma-bacilli, of considerable size, and
staining very deeply with ordinary aniline dyes.
Tube stab-cultures, derived from the plate, rapidly yielded abundant
growth, both on the surface and all along the course of the needle-track, consist
-ing of comma-bacilli of like character. The surface growth on old tubes ulti
- m a t e l y b e c a m e v e r y t h i c k , o f a w h i t i s h c o l o u r a n d d e v o i d o f a n y a p p r e c i a b l e
adhesiveness.
Cultivations on potatoes at first yielded characteristic growths certainly
and rapidly. These formed expansions, relatively thin, with irregular, ill-
defined margins, which were originally ochreous and gradually acquired a pink
tint of soft, smeary, inconsistent, creamy texture, and with a strong, sweet,
somewhat caseous odour. The constituent elements had the form of oval
cocci and short rods, but plate cultivations inoculated with them yielded pure
cultivations of colonies, which, both macroscopically and microscopically, were
identical with those of the primary one of the series.
Subsequently, in the case of cultures which had not been carried on direct
from potato to potato, but from continuous sub-cultures of the series of tube
cultivations, the growth was much slower, remained throughout relatively thin,
never acquired such a distinct pink tint, and consisted of beautiful, highly-curved
commas. This affords a striking example of the phenomenon, which is not infre
-quently encountered in connection with the morphological variation of certain
other species of vibrionic organisms, that, where growth is excessively rapid and
luxuriant, the constituent elements tend to separate from one another rapidly in
a more or less coccoid condition, whilst, when it is more retarded, they either
assume a simple bacillar form or appear in the form of rods composed of a series
of cocci included within a common sheath. At a still later period, as is not
unfrequently the case with vibrionic organisms, the growths in the continuous
series of tube cultures ultimately failed entirely to yield any on potatoes.
Growth in common gelatine is accompanied by rapid liquefaction of the
medium, which soon shows a wide tapering column of liquid extending along