146 LOTSY AND KUIPER, A PRELIM. STATEMENT OF THE RESULTS OF MR. 
contain members with only the normal four toes, which are still 
capable of transmitting the extra toe. The numbers in such fami- 
lies are not favourable to the suggestion that the irregularity is 
caused by a definite disturbing factor. (BATESON). 
Normal size of feathers on the hocks, is dominant to elongation 
of these feathers to forms quills — the Vulture-hock — of fanciers. 
The inheritance of the leg-feathering is not quite plain. Feathered 
leg partially dominates over clean leg. Hurst and DAVENPORT found 
dominance very irregular. Fy is intermediate and traces of leg-feathering 
are occasionally seen in the offspring of clean legged birds. 
Since CUNNINGHAM’S paper was written, we learned a great deal 
about this character by PUNNETT and BAILEY. We may resume 
their studies by PUNNETT’S own words. So far as our present know- 
ledge of the heredity of leg-feathering goes, we may say that in 
certain crosses it may behave as a single dominant, though domi- 
nance is always incomplete. In breeds with more heavily feathered 
legs there are grounds for supposing that two factors for leg- 
feathering may be present. Further it is possible that some strains 
of clean legged birds may carry an inhibitor for the feathered-leg 
character. The extent of the feathering shews considerable variation 
even in birds similarly constituted in respect of the factor or factors 
for feathered leg. Rarely a potentially leg-feathered bird may fail 
to shew even traces of the feathering. Probably clean-legged birds 
will be found in some cases to carry factors, hitherto not identi- 
fied, which affect the extent to which the feathering is developed. 
In support of this is the fact that a clean legged bird, mated with 
a bird in which the leg-feathering is slight, may give offspring in 
which the legs are strongly. feathered. | 
The comb of the Silky mostly is called a rosecomb. But this is 
not quite right. HOUWINK calls it a ,,crowncomb” (dutch kroonkam). 
We can describe it as a broad and short rather blooted comb 
divided at the posterior end into three points, and the surface of 
which shows brain-like windings and fissures. 
BATESON describes the comb of the Silky as a rose with atrifid 
element, which causes its posterior end to be divided into three 
irregular points. This character is dominant. In F9 from Silky X simple, 
regular rose combs are produced in those individuals which have 
the rose factor without this trifid element. 
