24” IIUMMINGBIRDS. 
     
    
   
   
    
     the gummy secretion of the bird‘s salivary glands. Egg/x, four to six, white, 
     
     use x ~50. 
     
    

    
     It is unnecessary to give any aids to the identification of a bird as 
     
     well known as the (‘himney Swift, or. as it is more frequently called. 
     
     “(‘himney Swallow." It is not. however, a Swallow. but a Swift, and 
     
     its structural relations are with the Hummingbirds and not with the 
     
     l’asserine Swallows. 
     
    

    
     Few sights in the bird—world are more familiar than the bow-and- 
     
     arrow-like forms of these rapidly flying birds silhoueted against the sky. 
     
     They are most active early in the morning and late in the afternoon, 
     
     when one may hear their rolling twitter as they course about overhead. 
     
     Sometimes they sail with wings held aloft over their backs, and sonic- 
     
     times, it is said, they use their wings alternately. It is a common 
     
     thing to see a trio of birds flying together. but it has never been ascer- 
     
     tained that the Chimney Swift is polygamous. 
     
    

    
     In some localities Chimney Swifts congregate in large flocks, mak- 
     
     ing their headquarters in a disused chimney which morning and even- 
     
     ing they leave and return to in a body. In perching they cling to the 
     
     side of the chimney, using the spilie-Iminted tails, as Woodpeckers do, 
     
     for a support. The habit of frequenting chimneys is, of course, a 
     
     recent one. and the substitution of this modern, artificial home for 
     
     hollow trees, illustrates the readiness with which a bird may take ad- 
     
     vantage of a favoring change in its environment. 
     
    
   
   
    
     FAMILY TROCHILIDZE. HL'MMINGBIRDS. 
     
    
   
   
    
     Hummingbirds are found only in the New World. About four 
     
     hundred species are known. They range from Alaska to Patagonia, 
     
     but are most numerous in the Andean regions of (‘olombia and Ecua- 
     
     dor. Seventeen species are found in the United States; only eight of 
     
     these advance beyond our Mexican border States. and but one species 
     
     occurs east: of the Mi 'ssippi. 
     
    

    
     Several species inhabit the depths of dark tropical forests, but as 
     
     a rule they are found with the flowers which bloom in the clearings, 
     
     or far overhead in the sunlight. They are not gregarious, but an 
     
     abundance of food sometimes brings large numbers of them together, 
     
     when the air becomes animated with their rapidly moving forms. 
     
     The smaller species fly so swiftly that their wings are lost in hazy cir- 
     
     cles. and it is difficult for the human eye to follow their course. The 
     
    
   
   
    
       
     
    
   
   
    
     fli 'ht 0f the larver s males is less insectlike, and each win r-beat can 
     
     3» n l L 
     
     be detected. Asa rule their Voice is a weak sr ueak or excited Chi J- 
     
     l l 
     
     pering. but some. of the tropical species have songs of decided charac- 
     
     ter which they sing with much energy. 
     
     Hummingbirds feed largely on insects, which they generally cap-