SPIRILLA RESEMBLING CHOLERA. 289 



motion. The edges of the bacterial mass are fringed with 

 radiating organisms (Fig. 87). 



In gelatin tubes the culture is very much like that of 

 cholera, but develops more slowly. 



Upon the surface of agar-agar a yellowish-brown 

 growth develops along the whole line of inoculation. 



On potato at the room-temperature no growth occurs, 

 but at the temperature of the incubator a luxuriant 

 yellowish-brown growth takes place. Sometimes the 

 color is quite dark, and chocolate-colored potato cultures 

 are not uncommon. 



In bouillon the growth which occurs at the tempera- 

 ture of the incubator is quite characteristic, and very 

 different from that of the cholera spirillum. The entire 

 medium becomes clouded, of a grayish-white color, and 

 opaque. A folded and wrinkled mycoderma forms upon 

 the surface. 



The addition of sulphuric acid to a culture grown in a 

 medium rich in peptone produces the same rose color ob- 

 served in cholera cultivations. 



The organism is pathogenic for animals, but not for 

 man. Pfeiffer has shown that chickens, pigeons, and 

 guinea-pigs are highly susceptible animals. The birds 

 when inoculated under the skin generally die pigeons 

 always. When guinea-pigs are treated according to 

 the method of Koch for the inoculation of cholera, the 

 temperature of the animal rises for a short time, then 

 abruptly falls to 33 C. or less. Death follows in twenty 

 to twenty-four hours. A distinct inflammation of the 

 intestine, with exudate and numerous spirilla, may be 

 found. The spirilla can also be found in the heart's 

 blood and in the organs of such guinea-pigs. When the 

 bacilli are introduced by subcutaneous inoculation, the 

 autopsy shows a bloody edema and a superficial necrosis 

 of the tissues. 



In the blood and all the organs of pigeons and young 

 chickens the organisms can be found in such large num- 

 bers that Pfeiffer has suggested the term u vibrionensep- 



19 



