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GUILFORD B. REED 



15 cm. above the stage and surrounded, except for a slit 2 cm. 

 wide, with an opaque reflecting screen in such a position that a 

 beam of light was projected to the stage at right angles to the 

 optical axis of the microscope (B, fig. 1). A solid black stage 

 provided support for Petri dish cultures or a groved block placed 

 on it provided for the support of tube cultures so as to bring the 

 surface of the media parallel with the stage. 



Fig. 1. A Diagram op a Binocular Microscope Arranged for the Sttjdt 

 or Colonies on the Surface of Media 

 A, Binocular microscope tube and focusing apparatus supported on a base 

 independent of the stage and at an angle of 45° with the stage; B, "daylight" 

 75 watt light surrounded by a screen except for a slit; C, solid black stage 

 and base; D, glass screen to protect open plate cultures; E, Petri dish 

 culture. 



The focal distance of the binocular is sufficient to permit of 

 the examination of tube cultures or Petri dish cultures with the 

 cover left on. For the fishing of colonies from cultures which 

 were to be further incubated a plain glass was supported 15 mm. 

 above the stage by strips along three sides leaving the right 



