TYPHOID FEVER. 375

intestine, exists there in typhoid fever, and adds no little
complication to the bacteriological diagnosis by respond-
ing in exactly the same manner as the typhoid bacillus
to the action of carbolic acid, by having colonies almost
exactly like those of typhoid, by growing in exactly the
same manner upon gelatin, agar-agar, and blood-serum,
by clouding bouillon in the same way, by being of almost
exactly the same shape and size, by having flagella, by
being motile, and, in fact, by so many pronounced simi-
larities as almost to warrant the assertion of some that it
and the typhoid bacillus are identical.

Not the least significant fact about the colon bacillus
is that it is also pathogenic and capable of exciting acute
inflammatory processes which are not infrequent, and
which sometimes serve to increase the seriousness of
typhoid fever.

At the present time we are in more or less of a quan-
dary about this extraordinary resemblance, but base our
differentiation of the 3pecies upon certain constant, slight,
but distinct differences.

The typhoid bacillus does not produce indol.

The open lymphatics and vessels of the intestinal ulcers
of typhoid favor the absorption of the bacteria in the diges-
tive tract, and the colon bacillus enters the blood no
longer to be a saprophyte, but now to be a virulent pus-
producer, and in many cases of typhoid we find suppura-
tions and other milder inflammations due to this microbe.
This is also a stumbling-block, for the typhoid bacillus
when distributed through the blood may act in exactly
the same manner.

The typhoid bacillus may enter the body, at times,
through dust (Klemperer and Levy), but no doubt, in the
great majority of cases, enters the digestive tract at once
through the mouth. It may possibly enter through the
rectum at times, as illustrated by the mention which
Eichhorst makes of the infection of soldiers in military
barracks through the wearing of drawers previously worn
bv comrades who had suffered from typhoid.