73
Spores are not formed, and it does not liquefy the media. Viewed by
transmitted light, the growth has a stippled, granular appearance like the
back of the looking glass. The growth on agar is alkaline.
Involuted forms, in the shape of small cocci, large cocci, pyriform
bodies, dumbbell-like forms, but without a handle, and swollen bodies
were produced on salt solution 4 per cent. in agar, also by 1/200,000 of
perchloride of mercury in agar; and by dipping into 25 per cent. sterile
salt solution momentarily and touching the agar surface at one spot
(blob culture on pure agar) in 24 hours.
When involution-form cultures were re-inoculated on to pure agar,
they reverted to the ordinary type met with.
The virulence of involuted forms was not investigated owing to
want of opportunity. The optimum temperature is 37 C.
Heat up to 120 F. killed the cultures on agar, and an old agar
tube re-sterilised failed to produce a growth on three occasions when re-
inoculated.
Exposure to strong sunlight for a few minutes killed the bacilli, but
mere staining them without beating did not seem to do so.
Alkaline bouillon containing fat produced flake-like islands under-
neath the surface, which fall to the bottom like vermicelli choppings on
shaking the containing flask. This growth appeared in 24 to 48 hours,
and continued to grow and develop fresh festooned flakes for upwards of
a month.
The growth on agar is sticky and viscid, and non-adherent to the
medium.
Bacilli were not found in the lochial discharges of aborted females,
nor in the catamenial discharge, nor in the bodies of the products of con-
ception in three out of four foetus examined.
Numerous bacilli were found in the inflamed gland by rubbing a
cover slip on a freshly-cut (sterile) surface, drying the slip, and staining
in the ordinary basic aniline dyes.
A beautiful double stain for tissues with specific plague bacilli con-
sists of alcoholic solution of eosin followed by methyl blue, the tissue
being fixed by alcohol without heat, and the slide gently washed in
water, between the two additions of dyes.
POST-MORTEM APPEARANCES.
In all 36 autopsies were preformed at Parel, the smallness of the
number being explained by the difficulty of obtaining leave to make post-
mortems on natives of India, owing to the objections of their relatives.
No case was examined without full consent of the deceased's friends,
and most of the bodies were unclaimed.