424 



BACTERIOLOGICAL ANALYSES 



(Fig. 207), each subdivision has an area of i square 

 centimetre; in Fakes' counter (Fig. 208), radii divide 



FIG. 207. Jeffer's disc, reduced. 



FIG. 208. Fakes' disc, reduced. 



the circle into sixteen equal sectors, and counting is 

 facilitated by concentric circles equidistant from the 

 centre. 



