142 



BACTERIOLOGY 



inoculation, and comes to resemble a capillary tube as the 

 liquefaction advances downwards and the evaporation pro- 





Superficial air-bubble 



Xeedle-track 



FlG. 50. THKUST-CULTUBE IN GELATINE OF THE CHOLERA BACILLUS (THIRD DAY). 



gresses. When liquefaction has gone still further the 

 bacilli sink in the needle-track, and the coherent mass of 

 bacteria forms a loose thread which is sometimes thicker 



