GROWTH OF CHOLERA BACILLI 143 



and sometimes thinner, and which extends to the bottom 

 of the funnel-shaped liquid cavity (fig. 50). In four weeks 

 liquefaction has made such progress that the entire mass 

 of gelatine is fluid. 



Cholera bacilli grow with a fair degree of luxuriance 

 upon other media also, forming on culture bouillon a wrinkled, 

 much-folded membrane, while the bouillon itself remains 

 tolerably clear. Only on shaking do the masses rise from 

 the bottom and render it cloudy. 



They grow also in sterilised milk, but in milk which has 

 not been freed from germs they undergo speedy destruction, 

 owing to the occurrence of acid fermentation. 



In sterilised water they grow rather actively and main- 

 tain themselves for a considerable time, so that cholera 

 bacilli find in many places the conditions required for their 

 increase. 



On agar the bacilli grow in the form of a whitish layer 

 spreading out from the line of inoculation. 



On potato they thrive even when the surface shows a 

 slightly acid reaction, but only at 30 to 40 C. In the region 

 surrounding the site of inoculation there develops a greyish- 

 brown layer, which gradually spreads and presents an 

 appearance almost identical with that exhibited by cultiva- 

 tions of the glanders bacillus. 



Blood serum is slowly liquefied by the growth of cholera 

 bacilli. 



The inoculated streak in the case of plovers' egg albumen 

 (Von Hovorka and F. Winkler) becomes covered with a 

 coating which reflects more light than the surrounding mass 

 of transparent white of egg, and consequently looks lighter. 

 If examined with a lens the streak, which slowly widens, 

 exhibits closely-packed, distorted colonies with a grey sheen, 

 partly united with one another. There is no liquefaction 

 of the nutrient medium. 



