PRINCIPLES OF GENETICS 



15 



law, vis., the law of free assortment. In addition to the 

 two classes, there are two other kinds of flies in the second 

 generation (Fig. 11). one with yellow wings and red 

 eves, and the other with gray wings and white eyes. 

 Together thev constitute 1 per cent of this generation. 



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Fig. 11. 

 The inheritance of two recessive sex-linked characters, vie., white 

 eyes and yellow wings and their ' ' normal ' ' allelomorphs, via., 



red eyes and gray wings. 



