SPIRILLUM METSCHNIKOVI. 595 
rather diminished in size, and the organs generally are 
normal in appearance. In the watery fluid large num- 
bers of spirilla are found; they are found in the blood 
of pigeons always, but only in the blood of young fowls. 
A few drops of a pure culture inoculated subcutane- 
ously in pigeons cause their death in eight to twelve 
hours. According to Gamaleia, fowls may be infected 
by giving them food contaminated with the cultures of 
the spirillum, but pigeons resist infection in this way. 
Infection may also be produced by way of the mouth 
by Koch’s method, a solution of carbonate of soda and 
laudanum having been previously administered. The 
animals then die with symptoms of acute gastro- 
enteritis; the intestines are found to be highly inflamed 
and their liquid contents contain numerous spirilla. 
In contradistinction to ithe pathogenic virulence of 
these spirilla for pigeons and guinea-pigs, the cholera 
spirillum is much less pathogenic. Pigeons are not 
killed by the intramuscular inoculation of pure fresh 
cultures of the vibrio cholere. Gamaleia has claimed 
that by passing the cholera spirillum of Koch through 
a series of pigeons, by successive inoculation, its path- 
ogenic power is greatly increased, and that when steril- 
ized cultures of this virulent variety of the comma 
bacillus are injected into pigeons they become immune 
against the pathogenic action of the vibrio Metschni- 
kovi, and the reverse. But Pfeiffer has shown that 
this statement is not founded upon fact. The patho- 
genic action of the vibrio Metschnikovi upon pigeons 
and guinea-pigs, producing in these animals general 
septiceemia and death, is, therefore, a characteristic point 
of difference between this and the spirillum of Asiatic 
* cholera. 
