82 
LEPIDOPTERA IN DIG A. 
I landed in Ceylon, October 25th, 1895, and I certainly thought that I had stepped 
into a land of butterflies. The harbour, streets, and large promenade, the Galle 
Face of the seashore, was alive with butterflies, and, being mostly composed of 
Catopsilias , looked like a snow-storm. In order to gain some idea of their numbers, 
1 selected two points, one at the edge of the sea and the other twenty yards from 
it, and then counted them as they flew past. The result of my calculation, and that 
of my companion, taken separately, gave 14,000 insects between 10 a.m. and 
2 p.m. The flight usually lasts about a week ; we have therefore 98,000 butterflies 
passing through a space sixty feet broad in twenty-eight hours. In round 
numbers 100,000.The butterflies, in whatever part of the island they 
happen to be hatched, immediately begin to migrate, so that on the same day the 
migration is as vigorous in one part of the island as in another. As the butterflies 
hatch in Colombo they immediately fly north, and their places are promptly filled by 
the insects coming up from Galle, the Galle ones by those from Hambantotte, and 
so on, round to Trincomalee, beyond which, in the uninhabited country to the north, 
I have been unable to trace them. The proof that the insects on the Trincomalee 
side really do follow the coast, and come to Colombo, is shown by the fact that it 
is only during the flights that certain butterflies, otherwise confined to that portion 
of the island, Papilio Jason , for instance, occur at Colombo, and are there seen 
migrating in the same frantic haste as their companions. On one occasion, on 
December 2nd, i.e. in the wet-season , I was observing the flight from Fort Frederick, 
Trincomalee. The butterflies came from the northern shore straight across the sea 
to the end of the peninsula on which Fort Frederick is built; several bushes of the 
food-plant of Galopsilia Pyranthe were growing there, and these were literally 
covered with eggs, as many as half a dozen on a single leaf; the bushes were so 
speckled with the multitude of eggs that they looked as if handfuls of sago had 
been scattered over them. The flights in November and December on both sides of 
the island undoubtedly comprise a majority of females, but scarcely a single larva 
out of this multitude of eggs could possibly have come to maturity; there was not 
enough food for half of them,, and on a previous migration the bushes not far off 
were completely stripped by the larvae. The insects comprising the coast flight are 
almost entirely Catopsilias , two species of Appias , Enploea Asela and Montana , in 
the Hill districts, and Danais septentrionis irregularly. I should have mentioned 
that the process of laying eggs was totally contrary to what one usually observes— 
there was no attempt to choose a suitable leaf, no deliberation displayed about the 
operation at all, but every female seemed possessed with the one idea of getting 
rid of her eggs with the utmost expedition, utterly regardless of the fate 
of the future larvae, and then madly continuing her flight. When in full 
migration they fly with great rapidity, and can give points to Colias edusa. 
