732 



THE AMERICAN NATURALIST [Vol. L 



Average grade of F 2 hoodeds — .62 — .73 — .94 



Average grade of uncrossed hoodeds — 1.28 — 1.64 — 1.83 



Average grade of uncrossed hoodeds as 



published (—1.31) (—1.18) (—1.75) 



Raised by cross 66 .91 .89 



Generation from which hooded parent came 2 3 



Average grade of F, hoodeds + 1.27 + .95 



Average grade of uncrossed hoodeds as 



published (+ 1.80) (+ 2.50) 



Lowered by cross .83 1.65 



B. Comparisons of the Standard Deviations of Extracted Hooded Bats with 

 the Standard Deviations of the Offspring of Hooded Eats of the Same 

 Grade and Generation as the Hooded Eats used as Parents in the 

 Various Crosses. 



Generation from which hooded parent came 2% 6 10 



S. D. of F 2 hoodeds 1.03 .90 1.18 



S. D. of uncrossed hoodeds 56 .33 .31 



S. D. of uncrossed hoodeds as published . . . (.49) (.44) (.24) 

 Increased by cross 47 .57 .87 



S. D. of F 2 hoodeds 50 .52 .45 



S. D. of uncrossed hoodeds 47 .47 .29 



S. D. of uncrossed hoodeds as published (.53) (.49) (.36) 



Increased by cross 03 .05 .16 



Generation from which hooded parent came 3y 2 4 7Vz 



S. D. of F a hoodeds 64 .60 .84 



S. D. of uncrossed hoodeds 53 .34 .26 



S. D. of uncrossed hoodeds as published (.48) (.46) (.35) 



Increased by cross 11 .26 .58 



Generation from which hooded parent came 2 3 



S. D. of F 2 hoodeds .90 .87 



S. D. of uncrossed hoodeds .38 .47 



S. D. of uncrossed hoodeds as published (.75) (.53) 



Increased by cross .52 .40 



If the difference between these selected generations lies 



in the changed position of the mode of continuons ger- 



