96 



SELECTION IN CLADOCERA ON THE BASIS OF 



TABLE 42. Summary of selection data by broods for Line 757 minus Continued. 



This selection made from a fourth brood of 71 individuals constituting a part of a test series. Data cot 

 included here as not strictly comparable to other data of this table. 



b Selection made, but time of beginning of experiment inadvertently omitted. 



the plus was the more reactive during every month except for 4 

 months during the period of irregularity in reactiveness in 1914 and 

 1915 (see pages 115-116 and table 44). 



Averages of the data by two-month periods (tables 41 and 42), 

 such as are given for Lines 695, 689, 711, and 719, serve still further 

 to compensate for temporary irregularities in reactiveness and are 

 used in the analysis of the data for line 757 and as a basis for the 

 curves given in figure 18s. 



