PART IY. 



MICRO-ORGANISMS PATHOGENIC FOR ANIMALS ONLY. 



Chicken Cholera (Bacillus Gallinarum). 



Bacillus gallinarum, the specific cause of chicken cholera, is 

 a very short and thick bacillus, with rounded ends, occur- 

 ring singly and in short chains (Fig. 144). Polar staining is 



FIG. 144. 



Bacillus of chicken cholera, from the heart's blood of a pigeon. X 1000. 

 (Fraenkel and Pfeiffer.) 



very marked, giving the organism the appearance of a diplo- 

 coccus. It does not form spores, neither is it motile. Gram's 

 stain is not applicable. Heat and drying are rapidly fatal. 

 It is strongly aerobic. 



All the cultures of this germ are absolutely devoid of any 

 characteristic. The culture is white in color, and develops 



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