112 GENETICS 



pure line, the average size of which is indicated by the 

 sign -f. The mean length of the entire lot, as shown 



FIG. 39. Diagram of the species Paramecium as made up of the eight 

 different races shown in Figure 37. Each horizontal row represents a 

 ' single race. The individual showing the mean size in each race is in- 

 dicated by a cross placed above it. The mean for the entire lot is at 

 the horizontal line. The magnification is about 24 diameters. After 

 Jennings. 



by the vertical line, is 155 micra. The total number 

 of individuals belonging to each size is not indicated, 

 but in every horizontal line their number is more 



