PREFACE. yii 



group of animals of comparatively recent geological origin, 

 still in course of development, and that in the Passerine 

 series no breaks have yet been established by the dying out 

 of intermediate forms, as has taken place in orders that have 

 survived greater geological changes. 



In one respect a difference may perhaps be traced between 

 the classification employed in this volume for birds and that 

 applied in the e Fauna of British India ' to other classes of 

 Vertebrata. The number of genera accepted or proposed by 

 Mr. Gates is larger in proportion than that adopted in the 

 Mammals, Reptiles, and Fishes. Personally I should have 

 preferred a reduction in the generic divisions of birds; 

 but, at the same time, I regard the question as one of con- 

 venience, there being, so far as I can see, no essential 

 distinction between generic and specific characters. Many 

 of the so-called " structural distinctions " in birds, such as 

 the arrangement of the feathers at the base of the bill and 

 the development of a crest, are probably purely ornamental, 

 and, like the colours of the plumage, connected with sexual 

 selection ; and I cannot see why the differences mentioned are 

 of higher importance than colour. It is, however, only fair 

 to say that many of the best ornithologists hold the same 

 views as Mr. Gates. It is also only just to add that I believe 

 this is the only detail of classification in which I see any 

 reason for differing with him. 



An account of the chief writers on Indian birds up to 1862 

 was given by Dr. Jerdon in the Introduction to the first 

 volume of the s Birds of India ' the principal authors enume- 

 rated, besides Jerdon himself, were Franklin, Tickell, Sykes, 

 McClelland, Burgess, Adams, Tytler, Kelaart, Layard, Hut- 

 ton, Theobald, and, above all, Hodgson and Blyth, to whom, 

 with Jerdon, may fairly be attributed the foundation of 

 Indian ornithology. A general notice of those who had 



