VOICES OF BIRDS. 



tion of continuing accidental deviations, are very re- 

 markable, and indicate a cause and original motive. 

 That some of the notes of birds are as language 

 designed to convey a meaning, is obvious from the 

 very different sounds uttered by these creatures at 

 particular periods : the spring voices become changed 

 as summer advances, and the requirements of the 

 early season have ceased ; the summer excitements, 

 monitions, informations, are not needed in autumn, 

 and the notes conveying such intelligences are 

 no longer heard. The periodical calls of animals, 

 croaking of frogs, &c. afford the same reasons for 

 concluding that the sound of their voices by eleva- 

 tion, depression, or modulation, conveys intelli- 

 gence equivalent to an uttered sentence. The 

 voices of birds seem applicable in most instances 

 to the immediate necessities of their condition ; 

 such as the sexual call, the invitation to unite 

 when dispersed, the moan of danger, the shriek of 

 alarm, the notice of food. But there are other 

 notes, the designs and motives of which are not so 

 obvious. One sex only is gifted with the power of 

 singing, for the purpose, as Buffon supposed, of 

 cheering his mate during the period of incubation ; 

 but this idea, gallant as it is, has such slight found- 

 ation in probability, that it needs no confutation : 

 and after all, perhaps, we must conclude, that 

 listened to, admired, and pleasing, as the voices 

 of many birds are, either for their intrinsic melody, 



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