Some breeding experiments on Catopsilia pyranthe. 705 
they fly with great rapidity, and can give points to Colas 
edusa. They select the sea-coast, I feel sure, simply to 
avoid obstacles. The road between Trincomalee and 
Kandy, which runs through dense forest, is also largely 
used by the migrating insects. When travelling south 
they have the N.E, monsoon behind them, but when 
turning north they meet a stiff wind which really seems 
to drive them to a faster flight. The breadth of the 
flight is usually not more than a quarter of a mile. 
The cross-barred line on the map shows one of the 
lines of migration of the two species of Appias, Paulina 
and Albina. They both breed in the low country, as 
shown by the square dots, and fly in a broad belt of 
insects about a quarter of a mile wide across the open 
downs at D’lawa, 4,000 feet, and up to the Horton Plains, 
7,000 feet, when they turn north toward N’Ehya, 6,000 
feet, cross the plateau towards Rambodde Pass at its 
northern end, and then make their way again to the low 
country somwhere near Kandy. Part of the flight edges 
away across the D’lawa Downs northwards and reaches the 
N’Eliya plateau through the Hakgala Pass. 
The migration of Huplea montana starts somewhere in 
the neighbourhood of the Hortons, and follows much the 
same course, so far as I know, as Appias. 
The uninterrupted line is a curious and interesting one ; 
it is that of Kallima philarchus, which annually migrates, 
sometimes in large numbers, though it is usually considered 
a rare insect. So far as I can at present ascertain there 
is only one migration annually in November or early in 
December. The insects come up from the low country to 
Haldumulle, then up the passes leading to the Hortons, 
and then across the plains to some uncertain locality, but 
where I have no idea. The insect does not occur in the 
Colombo or immediate Kandy districts nor about N’Eliya. 
It is extremely difficult to obtain assistance in carrying 
out an investigation such as this requires. Entomologists 
are few in number, and, with the exception of Trincomalee 
and one or two other places, Europeans are confined to 
Colombo and the Hill district. The remainder of the 
island is mostly covered with jungle, is thinly inhabited 
with only here and there a few overworked Government 
officials and ignorant natives. 
The reason for these flights is at present very obscure ; 
it was probably originally a question of food-supply. This 
