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Scientific Memoirs by
relatively very large size, and in certain instances demonstrate the presence of a
sheath including the ultimate elements very distinctly. The form which the ulti
- m a t e e l e m e n t s a s s u m e w o u l d a p p e a r t o b e t o a c o n s i d e r a b l e e x t e n t d e t e r m i n e d b y
c o n d i t i o n s i n t h e e n v i r o n me n t f a v o u r i n g o r i n h i b i t i n g r a p i d g r o wt h , f o r wh e n
growing slowly, at relatively low temperatures such as 70°F., rods or elongated
filaments tend to predominate, whilst the rapid growths developed at 95°F. are
ordinarily composed, in greater part, of short, oval or rounded cocci.
In agar-agar media, growth occurs both superficially and interstitially all
along the course of the track of the needle, in stab-cultures, and in dense small
colonies in the substance of plate ones. The surface growth in tube-cultures in
agar-agar media is soft, incoherent and chalky white, and, as in the case of agar-
agar cultures -of certain other species of choleraic bacilli, the substance of the me-
dium retains a light colour throughout and does not assume the strong yellow or
brownish yellow tint characteristic of old cultures of the majority of species. Old
cultures in agar-agar are specially characterised by the relatively very large size
and eccentric forms of the involution elements which they contain, and some of
which from their size very distinctly demonstrate the presence of an including
sheath surrounding included coccal elements.
Shortly after it was first obtained, cultivations of the organism in to per cent.
common gelatine were attended by slow, progressive liquefaction of the basis; The
process of liquefaction was unlike that attending the growth of any other species
of choleraic comma bacillus as yet met with. in. Calcutta, as there was not a trace
of any softening along the course of the needle track, but an even liquefaction, set
- t i n g i n o v e r t h e e n t i r e s u r f a c e o f t h e m e d i u m , a n d g r a d u a l l y a n d s t e a d i l y e a t i n g
its way down to the bottom of it. This was not dependent on absence of intersti
-tial development, as a finely clouded cone of growth soon made its appearance
along the entire course of the track. A little more than a year later all capacity
for liquefaction had disappeared, the characters of the growth otherwise remain
-ing entirely unchanged.
Cultivations in broth give pale, bright purple throughout, with pure sul-
phuric acid, 24 hours after their initiation, and very strong, pure purple after 48
hours' cultivation, and this although the growth is quite exceptionally slow, so
that after 48 hours the fluid is merely faintly hazy and has no pellicle.
Growth takes place on potatoes certainly and rapidly, in the form of a very thin,
moist, canary-yellow stratum. The edges of this are at first very ill defined, but
gradually become distinct owing to the fact that the uncovered surface of the
potato assumes a very deep pure umber tint. The cultivations rapidly acquire a
very strong, bitter-sweet odour.
In guinea pigs, subcutaneous injections of diffusions of considerable masses
of the growth in water gave rise to extreme dulness and, drowsiness, usually
followed by death in the course of a few days.
This organism has been under cultivation for a. year and nine months, and