2() 



THE AMERICAN NATURALIST [Vol. XLTVTII 



the F 7 generation means being 28.3 ± .11 leaves and 25.1 

 ± .15 leaves, respectively, but in the F 8 generations they 

 differ. Selecting minus extremes for the first two genera- 



Low Leaf Number in Family 77. New Haven, 1912. 



tions reduced the mean of that line from 26.3 ± .10 leaves 

 to 25.1 ± .15 leaves, but the third selected generation (F 8 ) 

 had a higher mean than the original family (27.3 ±.08 

 leaves) . The parent plant of this F 3 generation produced 



