HUMMING-BIRDS. 
no 
before so magnificent and luxuriant ; and they pass 
by these means before the dangerous season, to districts 
where the reparation of a previous wreck is proceeding 
with all the magical rapidity of tropical vegetation. 
The form of the wings is very nearly similar to those 
of the swift, ( Cypselus , Illiger,) whose power of flight 
every one is acquainted with. They in general ex- 
ceed the tail in length, unless when that member is 
extraordinarily developed. The exterior outline of 
the wing is very much curved, and the first quill is 
always longest, the others shortening gradually. The 
secondaries are very short, and the lesser wing-coverts 
occupy little space. The plumulets of the quills 
are narrow and compact, firmly united together, form- 
ing a substance, when used, almost like a thin plate 
of whalebone, and which, by presenting resistance to 
the air when struck, and allowing no part to pass 
through the webs, as in nocturnal feeding birds, pro- 
duces that humming sound which is heard during their 
suspension, and whence their common name has been 
applied. In all, the shafts of the quills are remark- 
ably strong and elastic, but in a few species, known 
