228 BRITAIN'S BIRDS AND THEIR NESTS. 



and widespread species, belong to this Order. Some indi- 

 vidual species are almost ubiquitous in the British Isles, 

 and may be met with at almost any time and place. 

 Certainly it is only on the bleakest mountain-top or on the 

 stormiest stretch of coast that the Order is at any season 

 unrepresented, while in most places its members will easily 

 outnumber those of all the other Orders put together. 



The commonness of the typical members of this Order, 

 and the absence of great diversity between them, render 

 a detailed general description unnecessary, and into the 

 deeper-seated characters we need not and cannot enter. 

 ' Passeres,' the scientific name, is merely a reference to the 

 Sparrow, which is to some extent a typical member. 

 ' Perching-Birds,*" a convenient popular designation, indicates 

 one of the more obvious structural points : three toes on 

 each foot are directed forwards, and the fourth backwards. 

 The last mentioned is always long and well developed, and is 

 actuated by an independent tendon. This arrangement gives 

 a power of grip of great service for perching, and as most 

 of the species are markedly arboreal in habits, this faculty 

 is an important asset. A moment's consideration will con- 

 vince the reader that to maintain the balance while perched 

 on a wire or slender twig, by sheer grip, is no mean feat. 



Another striking point about the Order is the vocal 

 powers of its members. No high development of song is 

 met with outside the group, while within it nearly, but not 

 quite, all the species possess true song-muscles and the 

 power of using them. The degree of talent is very great 

 in some species, but there is a great diversity of gifts. 



As regards mode of life, the members of the Order may 

 be divided into three main groups. A large number are 

 insectivorous. Those that are purely so are of necessity 

 only summer visitors to our area, with very few exceptions ; 

 but many mainly insectivorous species survive our winter 



