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BACTERIOLOGY 



inoculation, and comes to resemble a capillary tube as the 

 liquefaction advances downwards and the evaporation pro- 



>uperficial air-bubble 



Needle-track 



FIG. 50. THRUST-CULTURE IN GELATIXE OP 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 



