Phenomena of Variation and, Geograghicul Distribution. 165 



wings to tlie invigorating rays of the sum. In Auiboyna and other 

 towns of the Moluccas, the magnificent Deiphobus and Severus, and oc- 

 casionaly even the azure-winged Ulysses, frequent similar situations, 

 fluttering about the orange-trees and flower-beds, or sometimes even 

 straying into the narrow bazaars or covered markets of the city. In 

 Java the golden dusted Avjuna may often be seen at damp places on 

 the roadside in the mountain districts, in company with Savpedon, 

 Bathycles, and Agamemnon, and less frequently the beautiful swallow- 

 tailed Antiphates. In the more luxuriant parts of these islands one 

 can hardly take a morning's walk in the neighborhood of a town or 

 village without seeing three or four species of Papilio, and often twice 

 that number. No less than 120 species of the family are now known 

 to inhabit the Archipelago, and of these ninety-six were collected by 

 myself. Twenty-nine species are found in Borneo, being the largest 

 number in any one island, twenty-three species having been obtained 

 by myself in the Vicinity of Sarawak ; Java has twenty-seven species ; 

 Celebes and the Peninsula of Malacca, twenty-three each. Further 

 east the numbers decrease, Batchian jiroducing seventeen, and New 

 Guinea only thirteen, though this number is certainly too small, owing 

 to our present imperfect knowledge of that great island. 



In estimating these numbers I have had the usual difficulty to en" 

 counter, of determining what to consider species and what varieties. 

 The Malayan region, consisting of a large number of islands of gener- 

 ally great antiquity, possesses, compared to its actual area, a great 

 number of distinct forms, often indeed distinguished by very slight 

 characters, but in most cases so constant in large series of specimens, 

 and so easily se^Darable from each other, that I know not on what prin- 

 ciple we can refuse to give them the name and rank of species. One 

 of the best and most orthodox definitions is that of Pritchard, the 

 great ethnologist, who says, that "separate origin and distinctness of race, 

 evinced by a constant transmission of some characteristic pecidiarity of or- 

 ganization," constitutes a species. Now leaving out the question of 

 " origin," which we can not determine, and taking only the proof of 

 separate origin, "the constant transmission of some characteristic pjeculia riiy 

 of organization," we have a definition which will comj)el us to neglect 

 altogether the amount of difference between any two forms, and to con- 

 sider only whether the differences that present themselves are perma- 

 nent. The rule, therefore, I have endeavored to adopt is, that Avhen the 

 diflTerence between two forms inhabiting separate areas seems quite 

 constant, when it can be defined in words, and when it is not confined 

 to a single peculiarity only, I have considered such forms to be species. 

 When, however, the individuals of each locality vary among them- 



