Experimejits with Poultry 



125 



sive) normal feet, which gave 11 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. 



Fig, 10, B. Houdans. {Reliable Poultry Joiirtml.) 



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 Fj's were bred together, they 

 produced a large number of F^, 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. 



