188 JEAN BROADHURST 



upon the edge of the Petri dish and held it firmly against the 

 paper. 



Blue-print paper has been used for photographing photo- 

 genic bacteria, but this particular application is perhaps new. 

 Teachers will readily recognize the value of this method in per- 

 manently recording most of the results for which Petri-dishes 

 -are used. 



I had hoped to publish photographs of the prints as prepared. 

 The blueprints, however, on account of their color, do not repro- 

 duce well enough to show their real value. "Black and white" 

 architects' paper which could be used equally well is imported 

 and not to be procured at this time. 



