Wilson — Agouti-black Colour in Rabbits. 



599 



Professor Punnett, but as Z and s show themselves apparently to bring about 

 densing and diluting, we shall suggest that the name dilute cinnamon be 

 changed to dilute yellow. 



We may now set down the constitutions and the colours resulting from 

 the introduction of X'. We need do this for the heterozygous form only, 

 since, when X' is homozygous in a constitution, the colour is black. 



Thus, since there are at least seven factors carried by the experimental 

 rabbits, the decision as to whether the assumption of coupling or that of a 

 factor having more tlian one alternative is the more reasonable depends upon 

 finding whether there are four or three recessives operating in the foregoing 

 series of colours when X' is included. 



The writer's attention was drawn to this case by his colleague Dr. F. E. 

 Hackett, with wliom he has had the advantage of discussing it on more thai? 

 one occasion. 



SCIENT. PROO. K.D.S., VOL. XIII,, NO. XXXVII. 



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