ASIATIC CHOLERA. 



363 



around an enclosed bubble of air, and forming a funnel continuous 

 with the lower part of the growth ; the latter preserves for several 

 days its resemblance to a white 

 thread (Plate II., Fig. 1). In 

 about eight days, however, lique- 

 faction takes place along the 

 whole of the needle track. 



On the surface of agar-agar 

 the cultivation develops as a 

 white, semi-transparent layer, 

 with well-defined margin. The 



appearance on blood serum is very similar ; liquefaction very slowly 

 takes place. In broth they form a wrinkled film on the surface, 

 there is a rapid and abundant growth at the temperature of the 



FIG. 150. 



COLONIES OF KOCH'S COMMA- 

 BACILLI, x 60. 



FIG. 151. COVER-GLASS PREPARATION 

 FROM THE CONTENTS OF A CHOLERA 

 INTESTINE, x 600. (a) Remains of the 

 epithelial cells; (b) Comma-bacillus; 

 (c) Group of comma-bacilli (Koch). 



FIG. 152. COVER-GLASS PREPARATION 

 OF CHOLERA DEJECTA ON DAMP LINEN 

 (two days old), x 600. Great prolife- 

 ration of the bacilli with spirilla (a) 

 (Koch). 



blood, and the same applies to sterilised milk ; and they will even 

 multiply in sterilised water. In potato- cultivations the microbe 

 will only grow at the temperature of the blood (37 C.), forming a 

 slightly brown, transparent layer. Inoculation of a cultivation of 

 the bacillus in the duodenum of guinea-pigs, with and without 



