STERILE BREAD PASTE. 



67 



The steam steriliser is now prepared, and when the water is boiling 

 the flasks are placed in the steam chamber, where they remain for 



Fig. 26. — Aspergillus repcns growing on bread paste (extension of surface of 

 growth causing undulations.) 



half an hour. They are then removed, and placed in an ice-press for 

 twenty-four hours, and then once more steamed for thirty minutes. 



