y: 
ILLUSTRATIVE OF NATURAL SELECTION. 189 
Section D contains the strongest-bodied and most 
swift-flying of the genus. They love sunlight, and 
frequent the borders of streams and the edges of 
puddles, where they gather together in swarms con- 
sisting of several species, greedily sucking up the 
moisture, and, when disturbed, circling round in the 
air, or flying high and with great strength and 
rapidity. 
Geographical Distribution.—One hundred and thirty 
“species of Malayan Papilionides are now known within | 
the district extending from the Malay peninsula, on 
the north-west, to Woodlark Island, near New Guinea, 
on the south-east. 
The exceeding richness of the Malayan region in 
these fine insects is seen by comparing 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 collec- 
tions, 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 150 species, or about one- 
seventh more than are yet known from the Malayan 
region; but the area of the two countries is very dif- 
ferent; for while South America (even excluding Pata- 
gonia) 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 
