BACILLUS CO LI COM MUNIS. 395

The bacterium coli seems to be the pathogenic agent
of the greater number of summer infantile diarrheas.

This organism is the more often associated with the
streptococcus pyogenes.

The virulence, more considerable than in the intestine
of a healthy child, is almost always in direct relation to
the condition of the child at the time the culture is taken,
and does not appear to be proportional to the ulterior
gravity of the' case.

The mobility of the Bacterium coli is in general pro-
portional to its virulence. The jumping movement,
nevertheless, does not correspond to an exalted virulence
in comparison with the cases in which the mobility was
very considerable, without presenting these jumping
movements.

The virulence of the Bacterium coli found in the
blood and other organs is identical with that of the Bac-
terium coli taken from the intestine of the same indi-
vidual.

Lesage,1 in studying the enteritis of infants, found that
in 40 out of 50 cases depending upon the Bacillus coli
the blood of the patient agglutinated the cultures ob-
tained, not only from his own stools, but from those of
all the other cases. From this uniformity of action Le-
sage very properly suggests that the colon bacilli in these
cases are all of the same species.

The agglutinating reaction occurs only in the early
stages and acute forms of the disease.

It is not difficult to immunize an animal against the
colon bacillus. Loffler and Abel immunized dogs by
progressively increased subcutaneous dosage of live bac-
teria, grown in solid culture and distributed through
water. The injections at first produced hard swellings.
The blood of the immunized animals possessed an active
bactericidal influence upon the colon bacteria. It was
not in the correct sense antitoxic.

In intestinal diseases, such as typhoid, cholera, and

1 Semaine Medicate, Oct. 20, 1897.