J10 HUMMING-BIRDS. 



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 



