10 THE HOUSE SPARROW. 



Order Passeres. Perchers proper. 



The low insertion of the hind toe and its length ; its 

 great power of opposibility to the front toes ; and the 

 superior mobility of the same, which is secured by the 

 separation of its principal muscle from that which 

 Hexes the other toes collectively, perfectly adapt the feet 

 for grasping. The hind toe is always present, and is 

 never directed anteriorly, or laterally. The feet are 

 never zygodactyly esy ndactyle, nor semipal mate, although 

 the anterior toes, for a part or the entire length of the 

 basal joints, are usually immovably joined to each other. 

 For further particulars, the reader should examine some 

 standard work upon classification. 



The species belonging to this order are the typical 

 Insessores, and represent the highest grade of develop- 

 ment, as well as the most complex of the class. They 

 possess high physical irritability, the result of a rapid 

 respiration and circulation ; of all birds, they consume 

 the most oxygen, and live the fastest. 



The Passeres comprise the great majority of birds. 

 They are separated into two groups, ordinarily desig- 

 nated suborders, from the structure of the inferior larynx. 

 In one, this organ is a complicated muscular vocal appa- 

 ratus; while in the other, it is less developed, rudimen- 

 tary, or lacking. 



Suborder Oscikes. Singing Birds. 



The above constitutes the higher of the two suborders 

 previously referred to; comprising species, which possess 

 a more or less complicated vocal apparatus, consisting of 

 five sets of muscles ; but many of them are unable to 



