No. 537] INHERITANCE OF THE « EYE » IN V1GNA 523 



A fourth hypothesis is as follows : 



H = a factor for Holstein pattern. 

 E = a factor for Small Eye pattern. 



S=ra factor which enlarges the pigmented area, converting E into 



All four of these hypotheses are in complete agreement 

 with the statistical data, and lead to exactly the same 

 types, and the same ratios, in all generations. 



If we look upon the symbols as representing cell organs, 

 differences in whose functions are responsible for the 

 phenomena observed, then these four hypotheses are 

 identical. They all provide exactly the same set of cell 

 organs. The differences between the hypotheses are 

 found only in the nature of the functions which these cell 

 organs are supposed to perform. As we know nothing 

 definite about these functions, the hypotheses are essen- 

 tially identical within the range of present knowledge. 

 The functions assumed for the bodies represented by the 

 symbols of the first hypothesis seem to the writer to 

 accord more nearly with our meager knowledge of cell 

 chemistry. 



The author desires to acknowledge his indebtedness to 

 Mr. G-. "W. Oliver, who not only performed the cross- 

 fertilizations planned by the writer, but freely made 

 available similar extensive material of his own, which is 

 included with my own in these studies. Mr. Oliver also 

 grew the F 1 hybrids. He is also under obligations to Mr. 

 J. W. Froley, Mr. E. D. Carmack and Mr. W. E. Hum- 

 phries, who grew the F 2 plants and made the necessary 

 field notes ; to Mr. E. P. Humbert, who rendered valuable 

 assistance in classifying the F 2 material, and to Pro- 

 fessor C. V. Piper, agrostologist of this bureau, who fur- 

 nished seeds of the varieties used as parents in these 

 investigations, and made many helpful suggestions con- 

 cerning probable "factors" present in the varieties. 



