TBOCHILID^—TBOCHILINJE : RUBUUNG-BIRDS. 



469 



from the fact that, as in Passeres proper, the flexor longus hallucis is independent of the flexor 

 longus digiturum, — that is, the muscle wliicli bends the hind toe worlis separately from that 

 which flexes the other toes collectively. The arrangement of the thigh muscles is tlie same as 

 in Cypselidce. There is one carotid artery, the left ; a nude (jil-glaud ; no cuica. The ptcrylosis 

 is characteristic. 



The food of the Plummcrs ^yas formerly supposed to he the sweets of flowers. It is now 

 known that they are chiefly insectivorous. Their little nests are models of architectural heauty. 

 The eggs are always two in number. The young hatch weak and helpless, requiring to bo fed 

 by the parents, the Hummers being thus of altricial nature. The voice is not musical. 



The family is one of the most perfectly circumscribed in ornithology, and one of the largest 

 of its grade. So intimately and variously are the genera interrelated that every attempt to 

 divide it into subfamilies has proven unsatisfactory. The hummers are peculiar to Americ^a. 

 Species occur from Alaska to Pitigoni i but we ha-se ^ mere spimklni^ m tins ciunti} 1 he 

 centre of abundance is in 

 tropical South America, 

 particularly New Gra- 

 nada. Nearly 500 spe- 

 cies are current ; the 

 numljer of positively spe- 

 cific forms may be esti- 

 mated at about 400 or 

 more. The genera or 

 subgenera vary with au- 

 thors from .50 to 1.50. 

 The latest critical auth(jr- 

 ity upon the subject gives 

 426 species, assigned to 

 125 genera. (Elliot.) 



None of the known 

 N. A. Hummers exhibits 

 the extremes of shape of 

 bill or tail which some of 

 the tropical genera illus- 

 trate ; in only one (Calo- 

 tliorax lucifer') is the bill decidedly curved. Only one species is as much as 4 inches long, — 

 the magnificent Eugenes fuJgens. Some curious shapes of tail, including marked se.xual 

 characters in this respect, are exhibited by certain genera. 



Only one species, the common Euby-throat, is known to occur in the East; this was the 

 only one known to Wilson. Audubon gave four species, but one of them erroneously. Since 

 his time, however, new ftjrms of these exquisite creatures have successively been brought to 

 light over our Mexican border. In 185S, Baird gave seven (one of them Lampornis mango, 

 erroneously, as Audubon had done). In 1872, in the " Key," I was able to increase the number 

 to ten, but with two wrongly given (the Lampornis and Agyrtria linnaii). The same ten, with 

 the two errors, were given by Baird and Eidgway in 1874. Within a few years the discoveries 

 have been so many, that, after eliminating the two errors, I am able to describe no fewer than 

 fifteen peifectly distinct species of United States Humming-birds ; and I have no doubt that 

 several others will in due time be found over our Mexican border. 



The discrimination of the females and young is difficult ; but with the adult males there 

 should be no trouble. The following table is intended to enable the student to tell the genus 

 and species directly of any U. S. Hummer, if the specimen he has in hand be an adult male. 



Fig 2)1 - 

 (SLeppard del. 



1 \ tl 1 t 1 Hummu 

 Nichols sc.) 



iitst nearly nat size 



