PLATE II 



100 



a. 



b. 



PLATE COUNTER (Modified from Jeffers). 

 FOR COUNTING COLONIES OF BACTERIA. 



The cross lines divide the figure into square centimeters. The 

 numbers indicate the area of the various discs. The area of each 

 sector (a. and b.) is one-tenth of the whole area. (See page 126.) 



Pacing page 137. 



