36

drop of water of condensation in the tube, the bacillus first
commences to lose its virulence and then dies altogether.

Inoculation on too old dry agar tubes will produce no
growth at all.

The bacillus can be kept alive for months and the same
pathogenicity maintained if it be grown at 30°C. and subcul-
tured every time the water of condensation commences to
dry up, i.e., every 5th or 6th day. After two months it
should be passed through a rabbit to renew lease of
virulence.

In peptone bouillon the organism renders the medium
slowly turbid and there is a quantity of thick growth at the
bottom of the tube which rises up in clouds on shaking.
The bottom growth is easily broken up during the first few
days by shaking, but in older tubes it is almost impossible to
break up the stringy growth, so firmly is it glued together
by its mucoid substance. If the tube is incubated quite
unshaken for a few days, a thin scum forms on the surface
and climbs up the sides of the tube.

The bacillus will not grow at all anærobically. Tubes
of bouillon inoculated with the bacillus were put in Buch-
ner's tubes and incubated three days without result. The
tubes were then removed from Buchner's tubes and incu-
bated ærobically, and in 24 hours an abundant growth took
place.

                        II.—MORPHOLOGY.

The bacillus of Hæmorrhagic Septicæmia is, when
examined from the blood of an infected animal, a short and
thick bacillus averaging 2µ long and .4µ to .5µ broad. It
varies greatly in size and shape according to its environment.

Bacilli from the spleen often vary greatly in size, some
individuals being very much longer and thicker than those
seen in the blood.

In cultures the bacilli are sometimes very short indeed,
if they have been multiplying quickly, and they may even
be round. Rod-shaped forms are sometimes seen.

In recent cultures it is not uncommon to see three or
even more bacilli joined end to end, forming short chains
resembling streptococci.