4
Scientific Memoirs by
commas. No trace of interstitial growth . or of pink with 33 per cent. nitric
acid. Potato cultivations :—Growth occurring readily, but very. slowly. At first
very pale pink and devoid of any halo, ultimately becoming strong pink with a
limited deep brown halo. From the beginning, of a dense, leathery, cartilaginous
consistence. Very sharply defined marginally, and readily detached from the
substratum, leaving the surface of the latter quite clean. At first smooth, but
gradually becoming elevated into a beautiful, complex series of highly elevated
folds. Throughout, very dry, ultimately very thick, and forming a deep pink
wrinkled mass, continuing slowly to increase in bulk during periods of many
months' duration ; the thickness of the growth very excessive in relation to its
surface extension. Absolutely unlike the potato growths of any other choleraic
vibrio as yet encountered in Calcutta. Growth consisting of beautiful, small,
slender, slightly curved commas. Cover glass preparations, when heated, giving
off a strong honey-like odour.
Gelatine tube cultures :—Thin, dry, surface growth ; no track-growth or
solution of the basis.
Broth cultures :—Agree with the primary stool in giving very strong effer
- v e s c e n c e , b u t n o t a t r a c e o f p u r p l e o n a d d i t i o n o f m i n e r a l a c i d s . A l t h o u g h q u i t e
incapable of yielding any interstitial growth in agar-agar media, this organism gives
rise to conspicuous and rapid clouding of broth, unattended by the development of
any pellicle. In two other cases in which agar-agar cultures, although originally
yielding interstitial growths after some time give surface growths only,—G. V and
G. XXII, the former fails to yield any growth whatever in broth, and the latter
only faint clouding, and a thin, late, imperfect pellicle.
G. H. XXI. Received August 6th, 1895, and examined at once.
An abundance of nearly limpid, colourless fluid with a scanty deposit of
white, gelatinous flocculi. Smell strong, offensive. Reaction alkaline. Giving
beautiful violet peach-colour with pure nitric acid.
Plate cultures :—In 24 hours crowded with colonies. The interstitial ones
forming minute, ochreous knots, which, when they reached the surface, gave
origin to expansions of very pale ochreous tint and finely granular texture, exactly
like the purely superficial ones. They consisted of minute, well curved commas.
Agar - agar t ube cul t i vat i ons : —These wer e f or some t i me char act er i sed
by an abundant interstitial evolution of gaseous bubbles, a peculiarity not com
- m o n i n c o m m a s d e r i v e d f r o m c h o l e r a i c s o u r c e s , b u t w h i c h w o u l d s e e m t o b e
more frequent in the case of similar organisms derived from the intestinal tract
of fishes ; also by the occurrence of a limited amount of solution of the surface
of the medium. Both of these phenomena, after a time, ceased to be constant,
although, especially as regards the gaseous evolution, they occasionally mani
- f e s t e d t h e m s e l v e s e v e n i n r e l a t i v e l y l a t e s u b c u l t u r e s , p r o b a b l y i n c o n n e c t i o n w i t h
slight variations, in the constitution of the medium.