100 



SELECTION IN CLADOCEKA ON THE BASIS OF 



was 36.08 times its probable error. In every case in this test series 

 the plus brood had a lower reaction-time than the corresponding 

 minus brood. 



For the year August 1914-July 1915 (43 generations and 472 

 individuals, and 44 generations and 507 individuals, respectively) 



TABLE 45. Selection summary for Line 757. 



Time period. 



Nov. 16, 1912- 

 July 31, 1913 



Aug. 1, 1913- 

 July 31, 1914 



Test s e ri e s , 

 Sept. 1913. . 



Aug. 1, 1913- 

 Oct. 31, 1913 



Aug. 1, 1914- 

 July 31, 1915 



Aug. 1, 1915- 

 July 31, 1916 



Test series, 

 Apr. 1916... 



Mar. 1, 1916- 

 MaySl, 1916 



Aug. 1, 1916- 

 May 1, 1917. 



Strain. 



Plus. . 



Minus 

 Plus. . . 

 Minus 

 Plus.. 

 Minus 

 Plus.. 

 Minus 

 Plus. . 

 Minus 

 Plus. . 

 Minus 

 Plus... 

 Minus 

 Plus. .. 

 Minus 

 Plus. .. 

 Minus 



1-29 



1-28 



30-73 



29-70 



34 



33 



30-42 

 29-41 

 74-116 

 71-114 

 117-152 



9.0 

 11.5 

 41 10.0 

 1423.0 

 .2 



12.1 

 1310.4 

 .5 



11.8 

 14.0 

 116-163 37 12.9 

 143 1254.3 



140-145 

 138-146 

 153-181 

 164-181 



142 12 56 



29 11.0 



7 16 



7 16.6 

 20 12.3 

 2411.0 



4>;< 



683.7 

 753.0 

 409.0 

 559. 7 

 691.2 

 553.4 

 604.8 

 706.5 

 458.2 

 770.2 

 697.0 



564! 3 

 542.2 

 313.1 

 625.9 



226.8 



294.7 



260.7 

 309.3 



8.57 



171.9 

 290.4 

 235.; 

 301.7 11.34 

 6.26 

 292.0 15.72 

 166.4 

 305.4 

 290.5 



8.72 

 7.9; 



9.05 

 9.48 

 5.70 



8.84 



7. 



8.17 



-60.6 11.18 



-460.7 12. 



-162.218.16 



'-ib'g.bi'e.87 



-167.6 

 '-77'. 9 

 '-Slie'.S 18.37 17.01 



9.1218.38 



is'.4sii'.86 



TABLE 46. Same-day broods. Summary of data for Line 757. 



Time period. 



Nov. 16, 1912- 

 July 31, 1913 



Aug. 1, 1913- 

 July 31, 1914 



Aug. 1, 1914- 

 July 31, 1915 



Aug. 1, 1915- 

 July 31, 1916 



Aug. 1, 1916- 

 May 1, 1917 



Strain. 



Plus.... 

 Minus . . 

 Plus.... 

 Minus . . 



Plus 



Minus . . 

 Plus.... 

 Minus . . 



Plus 



Minus . . 



9 12.7 



9 11.0 



13.2 



// 11. 

 8 12.9 

 814.1 

 818.1 

 8 16.0 

 1 6.0 

 1 26.0 



1.3 



798.4213.38 

 8 133.47 

 3306.29 

 505.4 219.47 

 299.79 

 09.76 

 100.89 

 'IS. 56 

 50.28 

 5 184.86 



13.49 

 9.05 

 17.16 

 13.36 

 19.92 

 9.86 

 16.85 

 .13.09 

 13.85 

 24.45 



-.735 

 -200' 



16. 24 

 21 '.74 

 tl'.ll 

 21 '.34 



3.69 



c'.si 



9'.46 

 t'.66 



the mean reaction-times differed by 102.0 12. 87 seconds (table 

 45). This is a difference 7.93 times the probable error. None of the 

 8 minus same-day broods had a reaction-time lower than that for 

 the corresponding plus brood. The mean reaction-time for these 



