20 MENDELISM 



to produce a wrinkled green pea as a new variety. Would 

 he not at once say, after seeing the above result, " I have 

 not only lost the wrinkled shape but I have lost the green 

 colour as well ; it is therefore of no use to continue the 

 experiment"? But with Mendelism as a guide he now 

 knows that he must get what he wants in the Fij generation, 

 which will consist of — what ? — 



SY WY SG WG 



(9) (3) (3) (i) 



And the gardener would know that the wrinkled green, 

 being a pure recessive, must continue to breed true. He 

 would thus have produced a new variety — and, please note 

 he has obtained this result in the third year. 



Some beautiful results have been obtained by Mr. 

 Lock with Maize. Maize seeds are mostly yellow or white, 

 and may be smooth or wrinkled. By crossing these we get 



W x W = W ; YxY = Y; Y x W = Y. 



This shows that Y is dominant to white. The Fj 

 yellow is a hybrid = D[R]. If it be crossed with W 

 (Recessive) we ought, according to Law 4, to get yellow 

 seeds and white seeds in about equal numbers. The actual 

 numbers obtained by Lock were — 



26751 white, 

 26792 yellow — 



a very close approximation to theoretical requirements. 

 The yellow hybrid self-fertilized should produce 



3 Y, 1 W. 



Lock obtained 



16705 yellow, 



5568 white— (5568 x 3 = 16704). 



