STAPHYLOCOCCUS PYOGENES AUKEUS 



111 



and this gradually advances deeper along the thrust-canal, 

 while, as the funnel-shaped liquid area enlarges, the cocci 



Liquefied part 

 Collection of bacteria 



Needle-track in the 

 non-liquefied part 



Liquefied part of the 



gelatine 



Mass of bacteria collected 

 at the bottom of the 

 liquid funnel 



tFiG. 38. THRUST-CULTURES IN GELATINE OP STAPHYLOCOCCUS TYOGENES AUREUS ; 



TWO DIFFERENT FORMS OF GROWTH. 



sink to the bottom and begin to take on colour (fig. 38). 

 When, however, the culture is exposed, not to ordinary tern- 



