Medical Officers of the Army of India.

11

from its contents gave what was practically a pure culture of colonies of
comma-bacilli.

     The colonies were of relatively small size and circular outline, of a bluish tint
under oblique illumination, and, when viewed by directly transmitted light, pale
ochre, with a central dark nucleus immediately surrounded, first by a homogene-
ous yellow zone, succeeded by a shaded zone fringed by a delicate, pale, some-
what radiant margin. The constituent elements consisted of slender, pale, well
curved, and, in many instances, distinctly beaded comma-bacilli. The colonies
failed to show any pink under the influence of 33 per cent. nitric acid.

     Stab tube-cultures in agar-agar:—These were characterised by the following
features. Superficial growth occurred relatively slowly, but ultimately became of
a strong yellow colour. Interstitial growth, on the other hand, was very rapid
and diffuse, and was unattended by any gaseous evolution. The elements con-
sisted of beautiful, typical, highly curved comma-bacilli,

     Broth cultures:—These, within the course of 24 hours, became densely
clouded throughout and covered by a pellicle which presently assumed a
membranous character and became of considerable thickness. They struck,
bright, pure purple throughout with pure sulphuric acid within 24 hours.

     Potato cultures:—Growth occurred rapidly and assumed the character of
very thin, ill-defined, moist, almost colourless expansions, nearly odourless or at
most of a faint, yeasty odour, and devoid of any halo of discolouration of the sur-
face of the basis around them. In the earlier stages of its development it con-
sisted almost purely of coccal and diplococcal elements, and later, when the
growth was less rapid, showed similar bodies and a certain number of others
which had assumed the characters of distinct comma-bacilli, thus once more
affording an example of the occurrence of variation in morphological characters
in association with variations in rates of growth.

C.—COMMA-BACILLI OCCURRING IN BODIES OF WATER APART FROM
THE EXISTENCE OF ANY CHOLERA IN THE VICINITY.

     a . Species present in the water of a tank in the grounds of the Dalanda
Native Lunatic Asylum in Calcutta.

     The sample of water from which this species was obtained was taken in the
month of June 1896 at a time when no cases of cholera had occurred within the
Asylum for many weeks. Primary plate cultivations, as is usually the case with
those of tank-water, yielded colonies of several distinct species of schizomycete
organisms, and among these one, the elements of which were typical commas.
Plate sub-cultures of this species were characterised by possessing a faint
peculiar odour like that of herring-pickle, and similar to, but not so strong as,

C 2