OF THE MALAYAN REGION. 



n 



The exceeding ricliness of the Malayan region in these fine insects is seen by com- 

 paring the number of species found in the different tropical regions of the earth. From 

 all Africa only 33 species of Papilio are known; but as several are still undescribed 

 in collections, we may raise their number to about 40. In all tropical Asia there are at 

 present described only 65 species, and I have seen in collections but two or three which 

 have not yet been named. In South America, south of Panama, there are 120 species, 

 or about the same number as I make in the Malayan region ; but the area of the two 

 countries is very different ; for whUe South America (even excluding Patagonia) contains 

 5,000,000 square miles, a line encircling the whole of the Malayan islands would only 

 include an area of 2,700,000 square miles, of which the land-area would be about 

 1,000,000 square miles. This superior richness is partly real and partly apparent. The 

 breaking up of a district into small isolated portions, as in an archipelago, seems highly 

 favourable to the segregation and perpetuation of local peculiarities in certain groups ; so 



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