408 CONCLUSION. 



which these changes are mfluenced; the different 

 labours of birds in the preparation of their nests, and 

 the tending and feeding of their young, and the 

 reasons which lead some species to make far more 

 exertions in these respects than others ; the relative 

 periods of gro'v\1:h and decay in the different species ; 

 and the inferences which may be drawn from birds 

 with regard to the character of the particular season, 

 or of the climate in a more extended and prolonged 

 point of view. These and various others it is neces- 

 sary, in part at least, to know as introductory to the 

 useful study of birds ; and they involve so many facts 

 and principles both in natural history and natural 

 science general!}^, that if the reader will undergo the 

 labour, or, to speak more correctly, enjoy the plea- 

 sure, of learning all that is necessary for a proper 

 understanding of them, he will be astonished, not only 

 at the quantity of knowledge that he has accumulated, 

 but at the facility which he has acquired of obtaining 

 accurate and practical information upon every subject, 

 whether it more immediately belong to what is called 

 learning or to the common business of life. 



Bradbury and Evans, Printers, Whitefriars, London. 



