TROCHIL1D.E THE HUMMINGBIRDS. 359 



FAMILY TROCHILIDJE. THE HUMMINGBIRDS. 



CHAE. Size variable, but usually the smallest of birds. Bill subulate, but very vari- 

 able as to length; usually longer than the head, and generally straight, but occasionally 

 curved or even (in two genera) recurved. Feet exceedingly small and weak, the tarsus 

 not longer than the middle toe; claws well curved, sharp. Tail of ten feathers, exceed- 

 ingly variable as to shape. Win.? Swift-like, with exceedingly short secondaries and 

 strongly developed primaries; the latter ten; of which the first is longest, except in a 

 single genus (Aithurus); secondaries six. Plumage, variable, but usually adorned with 

 brilliant metallic tints, especially in the males. 



The range of variation in the details of form, size, and other 

 attributes among the four hundred and fifty known species of this 

 remarkable family is something wonderful, and it is therefore diffi- 

 cult to frame a diagnosis which shall express in few words the 

 exclusive characters of the family as a whole. Many species are 

 no larger than a common "Bumble Bee," but the largest is fully 

 equal to our Chimney Swift (Chcctura pelagica) in size. One 

 species has the bill only a quarter of an inch in length, while in 

 another this member is developed to the enormous length of three 

 and a quarter to four and a quarter inches, or more than the com- 

 bined length of the head, neck, body, and tail of the bird itself. In 

 the genera Avocettuht and Avocettinus the bill is recurved terminally; 

 but in Eutoxeres it has exactly a sickle-shape. The form and 

 relative development of the rectrices vary to such an extraordi- 

 nary degree that a whole chapter might be devoted to this topic 

 alone ; but here it will suffice to refer to this part of the subject 

 briefly : In the genera Cynanthus and Sappho the lateral rectrices 

 are greatly lengthened, with broad and rounded ends ; the rest 

 gradually shorter to the middle pair, which are only one fourth to 

 one fifth of the length of the outer pair. The tail is therefore deeply 

 forficate, and when spread is V-shaped. In the adult males the tail 

 feathers glow with the most brilliantly burnished metallic hues green 

 blue and violet in Cynanthus, fiery red and crimson in Sappho the 

 color varying with the species. In Steganura and Discura the lateral 

 rectrices are greatly elongated, gradually narrowed toward the end 



