126 



Experimental Zo'dlogy 



white and blue shanks, crested head, brown egg color, and broodi- 

 ness ; while leaf comb, single comb, black plumage, buff plum- 

 age, normal foot, clear shanks, uncrested head, white egg color, 

 and non-broodiness are all recessive to the dominants given 

 above. Some 0} these recessives may, however, be dominant over 

 others. Thus leaf comb and black plumage are dominant over 

 single comb and buff plumage that remain recessive. 



FlG. io,C. Silver-spangled Hamburgs. {Reliable Poultry Journal.} 



Hurst points out further that dominance may be complete, when 

 it is indistinguishable from pure dominance, or incomplete, 

 showing the influence of the recessive character in different de- 

 grees. For some characters the dominance is always complete ; 

 in some it is always incomplete; and in others it is sometimes 

 complete, but more often incomplete. The incomplete domi- 

 nants appear to be about twice as numerous as the complete. 



In the second generation F 2 the dominants are again complete 

 and incomplete. 



It is to be remembered that all the preceding characters behave 



