336 
Mil MACGILLIVRAY ON THE 
general, very minute, linear, cut even at the tip : a large 
patch on the back of the neck, having the feathers termi- 
nated by a sort of flattened stiff brush ; on the back, the 
feathers are very broad, and clipped, as it were, or cut 
even at the ends : the inner quills are weak, and curved 
outwards, so as to overlap some of the primaries. 
In the Tadorna, there is a similar characteristic group- 
ing of the feathers, affording five or six varieties of outhne, 
and many more of texture, &c. 
Between this and the King Duck, which belongs to the 
same division, the differences are obvious and great, inde- 
pendently of the protuberance at the base of the beak, or 
even of the inner quills, which are curved outwards, as in 
the Eider. 
Anas Boschas, Querquediila, Penelope and Crecca^ are 
very distinct in plumage. 
A. mduata^ besides other obvious markings, has a singu- 
lar appendage to the tip of the tail feathers, consisting of a 
short bristle, with an augmented and rounded termination. 
From the specimen here produced, it will be seen, that 
the character proposed might apply to at least a great pro- 
portion of the species of birds. My opinion is, that it 
could be extended to the whole ; but allowing only a par- 
tial application, even this would be a matter of import- 
ance ; and, were the attention of ornithologists directed to- 
ward this pointj there can be little doubt that discoveries 
would quickly be made, which would determine species 
and varieties with much greater precision than can be at- 
tained by attending to colour alone. I find, by an obser- 
vation of Temminck, regarding a species of Falco, that 
ViEiLLOT would seem to have attended, at least in some 
instances, to the differences exhibited in the forms of the 
feathers, and it is probable others may have done so too. 
As to making any claims of discovery, or imagining there 
