PREFACE, 
It is now many years since an attempt has been made to give an outline of the state of the Sc’e 
Ornithology, in a general elementary work. In the preface to the first edition ot my L\ 
Genera of Birds,” published in 1840, I stated that I had been for some time past occupied in drawing 
up the characters of the genera, the nomenclature of which I then promulgated, and that y 
on this subject might “ hereafter be given to the world m a more perfect form. The form whic 
have now adopted is one which will, I trust, be easily understood, even by the tyro who seeks to make 
himself systematically acquainted with the science ; but a few remarks and explanations may not be 
altogether unnecessary. 
The system, more fully carried out in the present Work, is the same with that of which my List 
of Genera ” furnishes the outline. It is founded as much as possible on the similarity of habits and on 
the consequent approximation of external characters of the different groups m relation to each ot er ; 
and has met with considerable approbation from various authors who have referred _ & 
alterations will be found in the positions of a small number of genera, but none affecting t e more 
important features of the system ; and the strict law of priority has been studiously o owe 
regard to the names employed, to the utmost of my knowledge and ability. 
Those genera only have been taken up, which were thought to be founded on characters of sufficient 
importance to warrant their general adoption. This part of the Work will be seen to be o 
innumerable difficulties, when it is considered how large a number of divisions have cen propose 
during the last few years ; but I have endeavoured to limit myself to such an amount of subdivision 
as appeared to me to afford the nearest approximation to a uniform system of nomenclature. tmay 
appear to some of my readers that I have exercised a severer scrutiny in the reduction o ese 
subdivisions in some subfamilies than that which has been applied to others; but I tin tna, i wi 
generally be found that such cases occur chiefly in those subfamilies which had cen su J ec ® y 
rpsnpct than is consistent with the 
some previous writer or writers to a more minute analysis 1 I ’ . . , 
1 _ ,i i OT1 j should be taken into con- 
uniformity of system required in a general work On e ° ’ know l e dge of the species at 
sideration that the several articles were prepared m ” CC °“ ” bcr of spec i es with which I have become 
the time of their publication; and that with the mcreased of ^ publioation of the 
acquainted during the five years that have elapse 
