HEEEDITY 



Gray (or agouti) = C B Br A; Cinnamon = C Br A 



Black = C B Br; Brown = C Br 



Albino (1) = B Br A; Albino (3) = Br A 



Albino (2) = B Br; Albino (4) = Br 



Proof of the correctness of this interpretation 

 may be obtained from crosses. Suppose the 

 four kinds of albinos described be crossed with 

 the same colored variety, brown; albino 1 will 

 produce gray offspring, albino 2 will produce 

 black ones, albino 3 will produce cinnamon 

 ones, and albino 4 will produce brown ones. 

 The cross with albino 1 brings together all the 

 four factors entering into the production of 

 gray, viz. C, B, Br, and A, hence the young are 

 gray. The cross with albino 2 brings together 

 the factors C, B, and Br only. The result is 

 black. The cross with albino 3 brings together 

 the factors C, Br, and A; result, a cinnamon 

 animal. The cross with albino 4 brings to- 

 gether no factors except C and Br; result, a 

 brown animal. 



Thus far we have considered merely varia- 

 tions which arise by loss of one or more of 

 the three unit-characters, A, B, and C. We 

 may now consider variations which arise 



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