90 
ON THE CLASSIFICATION OF BIBDS. 
all its quills appear to be nearly of the same length, and 
the contour forms a semicircle : this is the precise form 
under which this modification of the wing is most de- 
veloped, and our common 
wren {fig. 45.) exhibits it in 
full perfection. It is cus- 
tomary, however, in orni- 
thological descriptions, to 
say that a wing is rounded 
when the three first quids 
are graduated, that is, of 
very unequal lengths ; yet 
as this is not only seen in 
the wren, but also in the 
Drongo shrikes, and nearly 
all the true flycatchers, 
where the wing, taken as 
a whole, is decidedly long 
in proportion to the bird, it seems advisable to restrict 
the term round to such as accord with the defin- 
ition here given. Nevertheless there are so many gra- 
dations between the pointed and rounded shapes, by 
which the ttvo are immediately connected, that perhaps 
some term might be used with advantage to designate 
such as are of an intermediate character. The robin 
{Erytham rubecula), for instance, has a wing interme- 
diate in shape between that of the flycatcher and the 
wren, the three first quills being graduated ; and there 
are scarcely any perceptible divisions between the three 
series of quills ; nevertheless the fourth, fifth, and sixth 
are much more lengthened than the others, so as to give 
the wing, when closed, an appearance of being pointed. 
Such a wing is, therefore, as to length, moderate; and, 
as to its form, slightly pointed. By attention to these 
lesser modifications, much greater precision and accuracy 
would result than from adopting the present use of the 
term rounded. 
(83.) A nAsoRiAL wing is characterised, not by any 
particular arrangement in the proportion of the primaries. 
