312 



The Genetics of the Dutch Rabbit 



interpretation admittedly tentative in view of the present state of the 

 analysis, we may turn to examine Castle's facts. In doing so it will be 

 convenient to consider his different crosses separately, though not 

 necessarily in the order in which he gives them. 



(1) The cross between Self -colour and White Dutch (pp. 10-12y. A 

 White Dutch (/* of grade 17 was crossed with four self-coloured does, and 

 produced 33 young of grades 1-3. An F^ generation of 191 individuals 

 was raised, and in it was represented every grade of pigmentation from 

 self to grade 16. Such an F2 generation is certainly not to be expected 

 on the assumption that Self-colour and White Dutch belong to a system 

 of multiple aUelomorphs; and indeed Castle admits that it " is somewhat 



Fig. 2. 

 1 References given in italics are to Castle's paper. 



