PATHOGENIC BACTERIA. 107 



tions. The flagella can be well seen by staining according to the 

 flagella stain. 



Pathoyenesis. Experiment animals are not subject to cholera 

 Asiatica, but by overcoming two obstacles Koch has produced 

 choleraic symptoms in guinea-pigs. Nicati and Rietsch pre- 

 vented peristalsis and avoided the acidity of the stomach juices 

 by direct injection into the duodenum, after tying the gall-duct. 

 Koch alkalinizes the gastric juice with 5 c.cm. of 5 per cent, 

 sol. of sodii carbonas, and then injecting 2 grams of opium tinc- 

 ture for every 300 grams of weight into the peritoneal cavity 

 paralyzes peristalsis. The cholera culture then introduced 

 through a stomach-tube, the animals die in forty-eight hours, 

 presenting the same symptoms in the appearance of the intes- 

 tines as in cholera patients, the serous effusion containing great 

 numbers of spirilla. 



Comma bacillus in mucus, from a case of Asiatic cholera. 



Manner of Infection in Man. Usually through the alimen- 

 tary tract, with the food or drink, the intestinal discharges of 

 cholera patients having found entrance into the source of drink- 



