PATHOGENIC SPIRILLA. 



599 



it, after which the color test may be applied. The result of this, in 

 connection with the morphology of the microorganisms 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. 



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c * 



Fia. 179. Section through mucous membrane of intestine from cholera cadaver; a tubular 

 gland (a) is cut obliquely; in the interior of this (6), and between the epithelial and basement 

 membrane, are numerous spirilla. X 600. (Fliigge.) 



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 Lieberkiihn, and in some cases were seen between the 

 epithelium and basement membrane. As a rule, the spirillum is not 



