CHAPTER V. 

 CHICKEN-CHOLERA. 



BACILLUS CHOLERA GALLINARUM (PERRONCITO). 



General Characteristics. A non-motile, non-flagellated, non- 

 sporogenous, non-liquefying, non-chromogenic, aerobic bacillus patho- 

 genic for birds and mammals, staining by the ordinary methods, but 

 not by Gram's method, producing acids, indol, and phenol, and co- 

 agulating milk. 



The barnyards of both Europe and America are occa- 

 sionally visited by an epidemic disease known as chicken- 

 cholera, Huhner -cholera, or cholera de poule, which rapidly de- 

 stroys pigeons, turkeys, chickens, ducks, and geese. Rabbit- 

 warrens are also at times affected and the rabbits killed. 



The bacillus responsible for this disease was first observed 

 by Perroncito * in 1878, and afterward thoroughly studied 

 by Toussaint and Pasteur, f 



Morphology. The organisms are short and broad, with 

 rounded ends, measuring i X 0.4-0.6 //, sometimes joined 

 to produce chains. Pasteur at first regarded them as diplo- 

 cocci, because the poles stain intensely, a narrow space 

 between them remaining almost uncolored. This pecu- 

 liarity is very marked, and careful examination is required 

 to detect the intermediate substance. The bacillus does not 

 form spores, is not motile, and has no flagella.t 



Staining. The organism stains with ordinary anilin dye 

 solutions, but not by Gram's method. 



Cultivation. Colonies. Colonies upon gelatin plates 

 appear after about two days as small, irregular, white points. 

 The deep colonies reach the surface slowly, and do not attain 

 any considerable size. The gelatin is not liquefied. The 

 colonies appear under the microscope as irregularly rounded 

 yellowish-brown disks with distinct smooth borders and 



* " Archiv f. wissenschaftliche und praktische Thierheilkunde," 1879. 

 t " Compte-rendu de 1'Acad. de Sci. de Paris," vol. xc. 

 J Thoinot and Masselin assert that the organism is motile. "Precis 

 de Microbie," 2d ed., 1893. 



38 593 



