INOCULATION OF BREAD PASTE. 



69 



the flask plugged, and only then is it restored to its upright position. 

 During all these manipulations the operator is careful not to breathe 



Fig. 28. — Aspergillus nigrescens growing on bread paste. 



upon the flask, plug, or inoculating wire, and his hands are previously 

 washed in a 1 per 1000 solution of perchloride of mercury, to destroy 



