400 PA THOGENIC BA CTERIA.

from a recent autopsy are not pathogenic in moderate
amounts for rabbits or guinea-pigs. Liver-tissue pre-
served at 28° F. in an antiseptic wrapper is very patho-
genic for guinea-pigs when injected subcutaneously, but
Sternberg found that this pathogenesis was not true of
yellow fever livers only, as it developed also in control-
autopsies.

Extended research of the alimentary canal in yellow
fever showed the intestine to contain a great number of
bacteria, but no pure or nearly pure culture of any single
species, as in cholera. Few liquefying bacteria were
found, and the most abundant bacterium was, as in
health, the Bacterium coli communis.

The most important micro-organism met with was
Bacillus x (Sternberg), which was isolated by the culture-
method from a considerable number of cases, and may
have been present in all. It was not present in any of
the control-experiments. It was very pathogenic for rab-
bits when injected into the abdominal cavity. Sternberg-
says: "It is possible that this bacillus is concerned in the
etiology of yellow fever, but no satisfactory evidence that
this is the case has been obtained by experiments upon
the lower animals, and it has not been found in such
numbers as to warrant the inference that it is the veri-
table infectious agent."

The latest researches upon yellow fever are those of
Sanarelli.1 In studying the cadavers of yellow fever San-
arelli found them either entirely sterile or universally
invaded by certain microbic species, such as the Strepto-
coccus pyogenes, the colon bacillus, the protei, etc.,
which cannot be the cause of the disease. In the second
case he examined he was fortunate enough to find what
he is satisfied is the specific microbe, the Bacillus icter-
oides. In ii autopsies he never found the organism
alone, but always associated with the ordinary bacteria
mentioned above. The Bacillus icteroides must be sought
for in the blood and tissues, and not in the gastro-intes-

1 Brit. Med. Journ., July 3, 1697.