PATHOGENIC SPIRILLA. 599 
it, after which the color test may be applied. The result of this, in 
connection with the morphology of the microédrganisms forming the 
film and the character of growth in the gelatin plates, will estab- 
lish the diagnosis if the cholera spirillum is present in considerable 
numbers. If but few are present in the original material it may be 
necessary to make two or more series of plates and bouillon cultures 
before a pure culture can be obtained and a positive diagnosis made. 
aN 7 
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Gee, ve 
Fie. 179.—Section through mucous membrane of intestine from cholera cadaver; a tubular 
gland (a) is cut obliquely; in the interior of this (>), and between the epithelial and basement 
membrane. are numerous spirilla, x 600. (Pligge.) 
The spirillum is not found in the blood or in the various organs of 
individuals who have succumbed to an attack of cholera, but it is 
constantly found in the alvine discharges during life and in the con- 
tents of the intestine examined immediately after death; frequently in 
almost a pure culture in the colorless “rice-water” discharges. It is 
evident, therefore, that if we accept it as the etiological agent in this 
disease, the morbid phenomena must be ascribed to the absorption of 
toxic substances formed during its multiplication in the intestine. In 
cases which terminated fatally after a very brief sickness Koch found 
but slight changes in the mucous membrane of the intestine, which 
was slightly swollen and reddened; but in more protracted cases the 
follicles and Peyer’s patches were reddened around their margins, and 
an invasion of the mucous membrane by the “comma bacilli” was 
observed in properly, stained sections; they penetrated especially 
the follicles of Lieberktihn, and in some cases were seen between the 
epithelium and basement membrane. As a rule, the spirillum is not 
