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THE AMERICAN NATURALIST [Vol. XLVII 



lowed, produce vp (vermilion-pink) whereas it actually pro- 

 duces red. 



The use of capital letters for dominant factors and small 

 letters for recessive ones, while it may work well in some cases, 

 would be difficult of application in others. Brown color in 

 beans is dominant 2 to yellow but recessive to black. Shall we 

 then use B or bf True, Castle limits the use of the capital letter 

 to the "factor responsible for a variation which is dominant in 

 crosses with the normal" (italics mine), but who is to say what 

 is the normal color of beans? The use of capital letters for some 

 characters and small letters for others is, however, a minor 

 matter and would not alone disqualify the proposed terminology. 



When one is considering any new scheme, it is natural that he 

 should try it out on material with which he is familiar. I have, 

 therefore, attempted to apply Castle's suggestions to aleurone 

 colors in maize. To make the matter as simple as possible, I 

 will leave out of consideration color patterns and also the vari- 

 ous dilutions or intensities of color and limit myself to the state- 

 ment that aleurone may be purple, red, or white. In an account 

 of certain crosses published last year 3 I made use of the symbols 

 suggested by East and Hayes: C a general color factor, R con- 

 cerned with C in the production of red, P resulting in purple 

 when both C and R are present, and / an inhibitor of color 

 development. I listed 14 kinds of white aleurone. 4 Now if we 

 were to adapt Castle's formula? for albino mice to these white 

 maize types, we might use wP for whites transmitting purple in 

 crosses, wr for whites transmitting red, and wPr for those trans- 

 mitting both purple and red. But there are seven kinds of 

 whites, all of which might yield purples in appropriate crosses 

 with non-purples. How shall we distinguish between them? 

 Of course we could add to w the letters C, R, P, I or such ones 

 of these as might be necessary to indicate the factors latent in a 

 particular white, but wCRPI is no improvement over CRPI 

 from the standpoint of simplicity. Students in elementary 

 courses in genetics who have used maize for laboratory material 

 have had little trouble in calculating that when a white maize 

 CCrrPpli is crossed with another white maize ccRRPpli there 



2 On the presence-and-absence hypothesis it is hardly allowable to speak 



•American Naturalist, 46: 612-615, 1912. 



