S. C. Harland 199 



E the factor for New Era pattern on the seed coat, also producing 

 purple colouration of the tip of the young pod, and in the calyx and 

 peduncle. This factor is without efifect in the absence of R. 



The factor* for buff, N,is common to both parents. The cross is thus 

 New Era (ENR) by white (eNr), and the types appearing in F2. are : 



9ENR 3eNR 3ENp leNr 



New Era Baft White White 



It is recognised that the number of plants on which these conclusions 

 are based is very small, and it is intended to repeat the cross in order to 

 obtain a larger series of numbers. 



(e) The cross New Era by Black. 



The factors B (black), and E (New Era), both produce as one of their 

 effects anthocyanin colouration of the tip of the young pod, calyx, and 

 peduncle, though B produces a more intense colouration than E. It has 

 been shown that both these factors are allelomorphic to their absences. 

 Thus the cross black (BNR) by buff (bNR) will give in F^ the ratio 

 3 black to 1 buff, while the cross New Era (ENR) by buff (eNR) will 

 give in j^2, 3 New Era to 1 buff. If the factors B and E are inherited 

 independently, a cross between black and New Era should produce the 

 double recessive, buff, once in sixteen times in F2, thus : 



9BENR 3BeNR 3bENR IbeNR 



? Black New Era Buff 



The actual results obtained in the cross black by New Era may be 

 set forth as follows : 



Thei^i. Black. 



The F2. In F^ were obtained 73 black and 24 New Era. These 

 results approximate to the 3 : 1 ratio. 



Another cross between black and New Era gave the following 

 results : 



TheF^. Black. 



The F2. Segregation took place into (a) black, (6) buff New Era, 

 (c) red New Era. 



Plants Black Boff New Era Red Hew Era 



841 644 129 68 



197 

 Ratio... 3-8 : 1-0 



The presence of both red and buff New Era need not concern us at 

 this point. The important point to note is that the double recessive, 

 be, does not occur. 



