40 FIRST LIST OF THE BIRDS OF THE SOUTH KONKAN. 



cuticle. Many instances of this might be quoted. The Editor, 

 after examining the first batch of skins I sent him from this 

 district, was struck by the comparative darkness and brilliancy 

 of the plumage of many of the species. In particular the 

 specimens of Perdicula asiatica were said to be " so dark as 

 to be almost a distinct species." Of course this and other 

 similar instances do not prove that the two Glaucidia are one 

 and the same species. 



Before G. malabaricum can be suppressed still closer connect- 

 ing links must be found than even these Ratnagiri birds 

 afford. But that such links exist seems highly probable, and 

 I hope that Mr. Hume will be able to get a sufficiently large 

 series of representatives of this genus from all parts to enable 

 him to settle the point authoritatively. 



Since writing the above, I have read an article in the Nine- 

 teenth Century of January 1880, on the " Origin of" Species 

 and Genera," by Mr. A. R. Wallace, which contains some 

 remarks bearing very closely on the point above discussed. In 

 reviewing the work of Mr. /£. A. Allen in Eastern North Ame- 

 rica, and his elaborate observations as to the variations between 

 individuals of the same species, as to tint, distributions of 

 colours, and markings, &c, Mr. Wallace remarks : — 



" Colour also varies greatly in correspondence to latitude 

 and longitude. Dark coloured birds are said to become blacker 

 towards the south ; in others the red or yellow bands become 

 deeper ; while in those transversely banded the dark bands 

 become broader and the light ones narrower. Those with 

 white spots or bands have them smaller in the south, and 

 sometimes lose them altogether. These differences are some- 

 times so great that the extreme northern and southern forms 

 might be considered distinct species, were it not for the perfect 

 gradation of intermediate types in the intervening localities. 

 There is also an increase of intensity of colour from east to 

 west, as exhibited by the same or by closely-allied representa- 

 tive species inhabiting the Atlantic and Pacific coasts respec- 

 tively. In the desert plains of the interior, however, the colours 

 are paler than on either coast." 



The great variation in forms in India with reference to physi- 

 cal conditions — a subject which opens out a vast field of inquiry 

 hitherto but imperfectly explored — will no doubt furnish a close 

 parallel to the case of America. Picus mahrattensis, whose breast 

 assumes a darker hue on the west coast, is a striking instance of 

 intensification of colour from east to west. The case of Perdicula 

 asiatica, noticed above, is another good illustration, while a good 

 example of similar change from north to south is furnished by 

 Acridotliera tristis, Lin., of India, which becomes the doubtful 



