92 
ON THE CLASSIPIOATION OP BIRDS. 
the European genus, and are as long, and nearly 
double the breadth, of the chief quills. This struc- 
ture, with no very considerable variation, runs through 
the greater portion of the rasorial or gallinaceous birds, 
the quail, however, deserves a separate notice- its 
powers of flight are well known to be far greater 
than those of the partridge ; for it annually performs 
two long migrations, on its passage from Africa to 
ii-urope, and back again. Wc consequently find that 
Its wing unites the rasorial with the acuminated form • 
the first and second primaries being the longest, and 
double the length of the secondaries : this union of the 
two forms is also observable in the sand grouse of 
Africa (Plerocle»'), whose wings, for the size of their 
body, are much longer than those of any rasorial bird 
The only examples of the rasorial form of wing among 
the Perchers are restricted to the Trogons, the rasorial 
type of the J^issirofftres, 
(84.) Ample wings, which we shall now describe 
may perhaps be thought so closely allied to the rounded, 
torm as not to deserve a separate character ; nevertheless 
tliey produce a very different and peculiar sort of flight 
and are, consequently, formed upon a diftbrent inodeL 
1 he heron is the most familiar example of this struc- 
ture. In nearly all the species, the tertials are almost 
equal to the scapulars ; but the secondary quills which 
interyerie rapiiUy diminish in length from the tertials 
and become very short where they join the last of the 
primaries. Much of this form of wing, however 
longs to nearly all the natatorial and wading tribes’- but 
in the herons, and other ample- winged birds, the’nri 
manes are short, and the secondaries and tertials re 
markyibly broad: so that, although the flight is slow 
and heavy. It is regular, lofty, and can be long sustained. 
Any one who has seen the slow but steady course of the 
heron, immediately perceives that it flies like no other 
bird with which he IS familiar, excepting, perhaps, the 
lapwing, which has much of the same character. By 
this broad expanse of wing the heron mounts high in 
