SPIRILLUM CHOLERA ASIATICS. 



573 



bator. In bouillon the growth is rapid and abun- 

 dant; in the incubator at the end of ten to sixteen hours 

 the liquid is diffusely clouded, and on the surface a 

 wrinkled membranous layer is often formed. In gen- 



FIG. 79. 



A characteristic series of cholera cultures in gelatin ; one, two, three, four, 

 and six days' growth. (DUNHAM.) 



eral the spirillum grows in any liquid containing a 

 small quantity of organic matter and having a slightly 

 alkaline reaction. An acid reaction of the culture me- 

 dium prevents its development, as a rule; but it has the 

 power of gradually accommodating itself to the pres- 

 ence of vegetable acids, and grows upon potatoes, in 

 the incubator only, which have a slight acid reaction. 

 Abundant development occurs in bouillon which has 

 been diluted with eight to ten parts of water and in 



