Local Species 



strongly with the glossy black of his head, neck, 

 and under parts. In summer the cocks of the 

 two species grow more like one another owing to 

 the wearing away of the outer edges of their 

 feathers ; but it is always possible to distinguish 

 between them at a glance. The two species 

 meet at about the latitude of Bombay. Gates 

 states that in a certain zone, from Ahmednagar 

 to the mouth of the Godaveri valley, both 

 species occur, and they do not appear to 

 interbreed. 



It seems impossible to maintain that natural 

 selection, acting on minute variations, has 

 brought about the divergence between these 

 two species. Even if it be asserted that the 

 difference in the colour of the feathers of the 

 back of the two cocks is in some way correlated 

 with adaptability to their particular environment, 

 how are we to explain the fact that in a certain 

 zone both species flourish ? 



" A similar phenomenon is furnished by the 

 red-vented bulbul. This genus falls into several 

 species, each corresponding to a definite locality 

 and differing only in details from the allied 

 species, as, for example, the distance down the 

 neck to which the black of the head extends. 

 There is a Punjab Red-vented Bulbul (Molpastes 

 intermedius], a Bengal {Molpastes bengalensis), a 

 Burmese {Molpastes burmanicus], and a Madras 

 (Molpastes hcemorrhous) species. 



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