Experiments with Poultry 



125 



sive) normal feet, which gave n individuals with and 13 without 

 extra toes. A similar experiment with the hen (F^) gave analo- 

 gous results. Evidently in this case a character usually domi- 

 nant has become recessive. It is clear that unless great pre- 

 cautions are taken, such cases might easily be put down, in other 

 experiments, amongst the recessives. 



<^v 



' 1& 



FIG. 10, B. Houdans. (Reliable Poultry Journal^) 



The shank feathering of the Cochin dominates over the clear 

 shank of the Leghorn, Houdan, and Hamburg, but the dominance 

 is always incomplete. When the F^s were bred together, they 

 produced a large number of F 2 with feathered shanks, and a few 

 recessive clear shanks in the proportion of 28.7 : i. The Mende- 

 lian expectation is 3 : i. In other combinations the expectation 

 is much more nearly realized. Hurst concludes that "the Men- 

 delian principles are at work in these aberrant phenomena, but 

 are masked by something not yet perceived." 



Hurst's general conclusions are as follows: Dominant char- 

 acters are rose comb, white plumage, extra toes, feathered shanks, 



