INTRODUCTION. XV 



of the Philosophical Societies of the present day. The co- 

 pious list of Synonyms that will he found attached to each 

 species, may also be regarded in the light of a tahle of re- 

 ferences to other works, which it would he therefore need- 

 less to mention. 



Such remarks as appeared strictly necessary to the elu- 

 cidation of the several orders and genera, have heen given 

 under the characters of each, as they occurred in the course 

 of classification, as being explanatory of the grounds upon 

 which such general distinctions have been established. 



The recent more rapid progress of this science towards 

 maturity, may be, in a very great degree, attributed to the 

 attention paid by some of the later ornithologists to a point 

 which had been before almost totally neglected, viz. the 

 changes of plumage that the feathered tribe undergo in 

 their progress from the young to the adult state, as well as 

 those of a more peculiar and partial nature that are experi- 

 enced at a certain season of the year, sometimes by both 

 sexes, but more commonly only by the male bird. No op- 

 portunity has been omitted by the present writer to verify 

 (and frequently from the progress of experimental obser- 

 vation) many of the changes recorded by TEMMINCK, MON- 

 TAGU, and others; and, in order to their elucidation, 

 figures are given of some species at different ages, and at 

 different seasons, which will be more apparent in the se- 

 cond part of this work, as these changes chiefly exist, and 

 are most striking, in the water birds ; and have accordingly 

 been more confusing in their consequences. A separate 



