68 



THE BACTERIA IN ASIATIC CHOLERA. [CH. 



vegetable albumen, such as the white substance of Brazil nut, 

 extracted with dilute alkali, filtered, precipitated, and then 

 dissolved in dilute alkali ; to the solution is added Agar- 

 agar in the proportion of i p. c.) forms a translucent solid 

 nutritive medium. The comma-bacilli grow in this medium 

 fairly well, but not so well as in Agar-agar and meat-extract 

 peptone. They form a thin transparent greyish film on the 



FIG. 2. PLATE-CULTIVATION OF CHOLERAIC COMMA-BACILLI IN GELATINE 



AFTER FOUR DAYS AT 19 C. NATURAL SIZE. 



Many of the colonies have become confluent. 



surface with an irregular outline ; when sown into the depth 

 they form a greyish line indicating the channel of inocula- 

 tion. But in neither case does the growth even after several 

 weeks reach considerable dimensions, and in this respect the 

 medium is very inferior to the Agar-agar and meat-broth 

 peptone. 



(e)Egg-albumen and Agar-agar is much preferable and is 



