NOTICE OP THE CHAPTERS. 31 



learned, and nothing to stimulate the desire of 

 learning. 



In this little volume, I have taken the opposite 

 course. I have always begun with that which is 

 broad and general, such as we find it in nature ; but 

 in a few instances I have carried the analysis down 

 to the details, in order to show how easily the reader 

 can do the same for himself in all other cases. His 

 hope would have been fainter had I made the whole 

 details with only a few generalisations ; and if there 

 had been details only, hope of improvement there 

 would have been none. 



From the first chapter to the fifth, both inclu- 

 sive, there will be found, a general account of birds, 

 as distinguished from the other classes of vertebrated 

 animals. In these, their structures and the nature of 

 their more important functions, whether vital or 

 active, are treated in a light and sketchy manner, 

 though, it is hoped, to a sufficient extent for enabling 

 common readers to understand them more readily 

 and better, than if I had gone minutely and techni- 

 cally into the details. In this part of the book, there 

 will also be found Cuvier's structural classification of 

 birds, with a running commentary ; with a view of 

 showing how the study of animals may be abridged 

 by a good natural arrangement; but at the same 

 time, how many difficulties there are in the way of 

 such an arrangement, especially in the case of birds. 

 In this part of the work, as written accounts even 

 of a single specimen of each division would have 

 destroyed the unity and continuity of my plan, I 

 have added figures, generally of very typical species, 

 and all represented with the utmost fidelity. Through- 

 out the work, I have followed a similar method : 

 when it appeared to me that the reader would feel 

 inclined to know the details, I have given a repre- 



