ILLUSTRATIVE OF NATURAL SELECTION. 141 
sometimes even straying into the narrow bazaars or 
covered markets of the city. In Java the golden- 
dusted Arjuna may often be seen at damp places on 
the roadside in the mountain districts, in company 
with Sarpedon, 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 neighbourhood 
of a town or village without seeing three or four 
species of Papilio, and often twice that number. No 
less than 130 species of the family are now known 
to inhabit the Archipelago, and of these ninety-six 
were collected by myself. Thirty 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-eight 
species; Celebes twenty-four, and the Peninsula of 
Malacca, twenty-six species. Further east the num- 
bers decrease; Batchian producing seventeen, and New 
Guinea only fifteen, though this number is certainly 
too small, owing to our present imperfect knowledge 
of that great island. 
Definition of the word Species. 
In estimating these numbers I have had the usual 
difficulty to encounter, of determining what to con- 
sider species and what varieties. The Malayan region, 
‘ consisting of a large number of islands of generally 
great antiquity, possesses, compared io its actual area, 
a great number of distinct forms, often indeed dis- 
