744 THE AMERICAN NATURALIST [Vol. XLVI 



describing the facts. But the great factor in the magnitude 

 of x 2 is the deficiency in the wrinkled green seeds, and the 

 authors have suggested a reasonable biological explanation for 

 this deficiency. 



Illustration III. Color in Oats 



Nillson-Ehle, -fide Baur. Einf. Exp. Vererbungsl., pp. 66-67 



Thus x 2 = .0476 only. P is not tabled for x 2 < 1, since the 

 probabilities of such deviations being due simply to errors of 

 sampling are so enormously high. Theory and observation 

 could hardly agree more perfectly. 



Illustration IV. Body Color in Drosophila 

 Morgan, Journ. Exp. Zool., 13: 35, 1912 



Here x 2 is over 40, the odds against the deviations, being due 

 to errors of sampling, are so enormously great that it is idle to 

 express them in figures. In short, the facts do not substantiate 

 the hypothesis, and Professor Morgan has himself suggested 

 possible reasons for the disagreement. 



Illustration V. Partia: 



Purple, lo 

 Red, long 



:he 7:1:1:7 basis, x 2 = 12.7699, P = .0053. For the 

 :15 hypothesis, x * = 3.6375, P = .3086. Thus the 



