182 SPECIAL BACTERIOLOGY 



Motility . N on-motile . 

 Spore Formation absent. 



Staining Reactions. Exhibits the usual bipolar staining with 

 the ordinary aniline stains. Does not stain by the Gram method. 



Cultivation. It is an aerobic, non-liquefying bacillus, growing in 

 the usual culture media at room temperature. The growth in the 

 various media corresponds to that of the bacillus of fowl cholera. 



Pathogenesis. Affects ducks, but not chickens or pigeons, and 

 only kills rabbits when injected in large quantities. Ducks die in one 

 to three days from subcutaneous inoculations, or by ingestion of food 

 containing the bacillus. 



BACILLUS OF FOWL CHOLERA. 



(Ger. Bac der Huhner Cholera ; FT. Cholera des poules). 



This disease often occurs in poultry as an epizootic ; it is char- 

 acterized by diarrhoea and death in one to two days. 



Microscopical Appearances. Very short bacilli of varying size. 

 Motility. Non-motile. 

 Spore Formation absent. 



Staining Reactions. In cover-glass specimens the bacilli stain 

 with the ordinary aniline dyes, more at the pole than in the middle, 

 giving them the appearance of diplococci (see Photomicrograph, Fig. 66), 

 but by intensive staining they appear as genuine bacilli. By the Gram 

 method the bacilli are decolorized. 



Vitality. Exhibit slight resistance to heating and drying, but 

 remain lying a long time in contaminated or mixed cultures. 



Biological Characters. The bacilli grow on the ordinary media 

 at both room and incubator temperature. 



On Gelatine Plates, in the deep portions of the medium, they form 

 round, irregular, brownish discs, and on the surface the growth is slow 

 and limited. 



In Gelatine Stab Cultures the growth occurs on the surface, as well as 

 along the course of the needle. The surface growth consists of a 

 delicate greyish-white coating. 



On Agar and Blood Serum Media a glistening whitish coating is 

 formed. 



On Potatoes it does not grow at ordinary temperature, but at higher 

 temperatures a transparent, greyish -white, flat coating is formed. 



