THE POULTRY BOOK. 
311 
THE TUFTED, OR CRESTED DUCK. 
This is another variation which has been perpetuated and even increased by 
the care and selection exercised by man. 
It is characterized by a large tuft of feathers on the top of the skull, very 
like that of a Polish hen. In some cases this globular crest attains a large size, 
and renders the birds very remarkable objects. In the skulls of some specimens 
that we have examined after death, we have noticed a deficiency of the bones 
of the forehead, their place being supplied by a cartilaginous thickening of the 
membranes under the base of the crest. 
THE FARM-YARD DUCK 
Calls for no special description at our hands. In size, early maturity, and 
aptitude to fatten, the mongrel races that are found in too many localities are 
far inferior to the Aylesbury or Eouen breeds, whether regarded as profitable 
for the table or market, or viewed as ornamental and elegant water-fowl. 
Before concluding this long list of the varieties of the domesticated duck, we 
may call attention to another variation that not unfrequently occurs, namely, the 
absence of the web or membrane between the toes ; this also is hereditary, 
but it is not generally perpetuated by the owners, as the ducks have not the 
power of swimming with vigour. We mention it merely to notice a very common 
error concerning its production, namely, that the birds so varied are the result of 
a union between the common fowl and the duck : it should be needless to insist 
on the absurdity of such a belief, which has no foundation whatever in fact. 
