INTRODUCTION. 



I. OF CAGE-BIRDS IF GENERAL. 



BY the term Cage-birds,* I understand such as amateurs usually 

 keep in confinement, for the sake of their beautiful plumage, 

 their agreeable song, their lively disposition, or from the desire 

 of studying their various peculiarities. For these purposes it 

 is especially necessary to be able to distinguish between the 

 sexes, since, as is well known, the males are, in almost every 

 respect, more valuable than the females. I shall therefore in 

 the following pages, pay particular attention to the varieties 

 of colour, and other characteristics, by which this distinction 

 may be effected. As, however, many birds are untameable, 

 and many more would not repay the trouble necessary to tame 

 them, the number of species which come within the scope of 

 the present work is very small, when compared with the whole 

 number known to the ornithologist. 



II. Or THE YOICE AND SONG OF BlRDS. 



EVERY species of bird has a peculiarity of voice possessed by 

 no other. By this variety of vocal endowment, birds are not 

 only distinguished above the rest of the animal creation, but 

 are enabled to express to one another their wants and passions. 

 There can be no doubt that this power of communication exists 

 not only between the sexes, but between all individuals of the 

 same species. The least experienced observer of nature knows 

 that the approach of danger is expressed by a universally in- 

 telligible cry ; which, if uttered by the Wren, for instance, is 

 understood by the Turkey-cock, and vice versa. Of whatever 

 species the one may be, which first perceives the approach of 

 a bird of prey, it is able to excite the attention of all birds in 

 the neighbourhood by its peculiar cry of warning. As soon as 

 the Blue-tit utters her Iss ! so indicative of fear and terror, 

 which, nevertheless, she seems sometimes to do from pure love 



* The German word is Stubenvogel, which, translated literally, is 

 chamber-birds; but as these chambers are, so to say, cages on a large stale,. 

 the translator has preferred the term Cage-birds. 



B 



