66 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



The comma-bacilli grow equally well in neutral brcth. I 

 have seen them grow fairly well even in faintly but distinctly 

 acid broth, but the amount of turbidity and of precipitate 

 was far less than in alkaline and neutral broth. 



(b) In milk the comma-bacilli grow well, but not so 

 luxuriantly as in broth ; the appearance of the milk (as has 



^fll 









FIG. 21. PLATE CULTIVATION WITH COLONIES OF CHOLERAIC COMMA-BACH. LI, 

 SEVHNTY-TWO HOURS OLD. MAGNIFIED FIFTY TIMES. FROM A PHOTOGRAPH 

 AFTER PLAGGE. 



been pointed out by Koch) remains practically unaltered, 

 and the casein is not precipitated. Mr. Warrington (Journal 

 of the Chemical Society, 1888) has noticed curdling of milk to 

 take place by the comma-bacilli when growing at 3oC. 



(c) In Agar-agar mixture (Brand's meat-extract i tin, dis- 

 solved in ico ccm. of distilled water, to which is added 10 



