SYSTEMATIC AND DESCRIPTIVE. 233 



their middle* (vide p. 135). When cultivated by 

 introducing a drop of the infected blood into sterile 

 chicken-broth, a number of round bodies, undergoing 

 rapid movement and as a rule united as diplococci, 

 or elongated and contracted in the middle, appear 

 in the broth, which is at first slightly milky, but be- 



FIG. 79. BACTERIUM OF CHICKEN CHOLERA ; BLOOD OF 

 INOCULATED HEN, x 1200. 



comes limpid, and the microbes at the same time 

 pass into a finely granular state. From this, how- 

 ever, fresh cultures can still be started. Cultivated 

 in a test-tube of nutrient gelatine, after from three 



FIG. 80. BACTERIUM OF CHICKEN CHOLERA, FROM MUSCLE JUICE 

 OF INFECTED HEN. x 2500 [from a Photograph]. 



days to a week there develops along the needle 

 track a fine, almost imperceptible, greyish thread 

 without liquefaction of the gelatine (Plate III., 

 Fig. 2). The growth is exceedingly scanty, even 

 after several weeks. 



Fowls suffering from the disease usually die very 



* Cornil and Babes, Les Bacteries. 



