SPIRILLA RESEMBLING CHOLERA. 343
ilium. At times the growth may be a little more rapid.
The growth on agar is very luxuriant, and gives off a
pronounced odor of indol. Loffler's blood-serum is ap-
parently not a perfectly adapted medium, but upon it the
organisms grow, with resulting liquefaction. Upon po-
tato at the point of inoculation there is a thin, glazed,
more or less dirty yellow, shading to brownish deposit that
is sometimes surrounded by a flat, dry, lusterless zone.
In litmus milk a slightly reddish tinge is found after
twenty-four hours at body temperature. After forty-eight
hours this is increased and the milk is coagulated. In
peptone solutions indol is produced. No gas is pro-
duced in glucose-containing culture-media. The organ-
ism is a facultative anaerobic spirillum. The thermal
death-point is 50° C. for five minutes.
The organism is pathogenic for pigeons, guinea-pigs,
and mice. The pathogenesis is much like that of the
Spirillum Metschnikovi. No Pfeiffer's phenomenon was
observed with the use of the serum of immunized ani-
Immunity was produced in pigeons, and it was found
that their serum was protective against both the Vibrio
Schuylkiliensis and Spirillum Metschnikovi, the immun-
ity thus produced being of about ten days' duration.
In a second paper by Abbott and Bergy1 it was shown
that the vibrios were found in river water during all
four seasons of the year, and in all parts of the river
within the city, both at low and at high tide. They were
also found in the sewage emptying into the river. The
spirilla were also found in the water of the Delaware
River as frequently as in that from the Schuylkill.
One hundred and ten pure cultures of spirilla were iso-
lated from the sources mentioned and subjected to routine
tests. It was found that few or none of them were iden-
tical in all points. There seems, therefore, to be a family
of river spirilla related to each other like the different
colon bacilli are related..
1 Journal of Experimental Medicine^ vol. ii., No. 5, p. 535.