YELLO W FE VER. 40^
yellow fever. This fact is not only striking evidence in
favor of the specific nature of the Bacillus icteroides, but
it places the etiological and pathologic conception of yel-
low fever on an altogether new basis.''
The discovery of the Bacillus icteroides, and especially
of its toxin, entirely changes our view of the pathology
of the disease. Instead of being a disease of the gastro-
intestinal tract, as one would conclude from the symp-
toms, " all the symptomatic phenomena, all the functional
alterations, all the anatomical lesions of yellow fever, are
only the consequence of an eminently steatogenous,
emetic, and hemolytic action of the toxic substances
manufactured by the Bacillus icteroides.7'
The mode by which the Bacillus icteroides enters the
body to produce the disease has not been made out.
The digestive and respiratory tracts are the most likely
Sanarelli points out that when it happens that a mould
develops ne2r the Bacillus icteroides, the products of
material exchange of this hyphomycete or the transfor-
mation effected by it, are sufficient to nourish the ba-
cillus and enable it to live and multiply, whereas it
would be otherwise condemned to a more or less early
There seems to be no particular mould possessed of this
power, as of six experimented upon all were capable of
it. Sanarelli is of the opinion that in the holds of ships
and in damp places generally the presence of moulds
favors the development of the Bacillus icteroides.
About the same time that Sanarelli published his
researches, Havelburg announced1 the discovery of an
entirely different bacillus. Without entering into a long
description of Havelburg's bacillus, which seems to be
far less established in its specificity, the following are the
chief characteristic and differential points:
The bacillus is found in the stomach and intestine and
in the "black vomit" It is almost the sole orgaii-
1 Ann. de VInst. Pasteur, 1897.