NOTES. 187 



intensity to the November flight of the yellow Catopsilia which 

 occurs annually northwards over Colombo. The great majority 

 consisted of the brown Euploea asela, but perhaps two or three 

 per cent, (this small percentage representing a goodly number, so 

 vast was the total swarm) were the speckled Danais septentrionis, 

 the male of which has a peculiar pouch on the hind wing. They were 

 passing in a southerly direction over Trincomalee. 



The brown Euploea is a very common species occurring diffusely 

 throughout the country, often met with in considerable companies 

 settling upon damp places by the roadside. This time, however, 

 there was no such casual meeting of individuals alternately flitting 

 low and resting, but a high concerted and sustained movement over 

 the trees and houses and along the seashore in incredible numbers. 

 It is a seasonal flight, and is recognized as such by the inhabitants 

 of the district, who aver that the butterflies are going to Kataragam, 

 a famous Hindu sanctuary in the south of the Island, a few miles 

 from Tissamaharama. 



Small samples of each kind were taken for examination. Of 16 

 examples of Euploea asela, 12 were males, 4 females ; of 14 Danais 

 septentrionis, 10 were males, 4 females. 



The suddenness with which the apparition vanished was remark- 

 able. Looking out over the maidan in front of the resthouse at 

 1.25 P.M. not a butterfly was to be seen. It was essentially a 

 mid-day fight. During the afternoon a few isolated stragglers weje 

 noticed, but the main advance ended sharply as described. It is 

 not difficult to assign a climatic reason for this flight. The date at 

 which it occurred was during the lull which succeeded a strong access 

 of the south-west wind, preceding the onset of the north-east rains, 

 the clouds for which were already banking up to burst in a blind 

 squall the next evening. In this part of the Island the south-west 

 and north-east monsoons coincide accurately with the dry and rainy 

 seasons respectively. This is not the case in the Western Province. 

 The south-west blow which freshened during the last ten days of 

 September was accompanied on the west coast by heavy rain, but 

 not in the neighbourhood of Trincomalee. 



Probably the swarm had been travelling in a column for miles 

 along the seaboard. No enemy was following them. I do not 

 know whether a corresponding flight had taken place at noon on 

 the day previous, but I do know that on the day following, which 

 happened to be the occasion of the annual Kumbom or Flower 

 Festival, there was no repetition of it. 



The fact of the simultaneous emergence of the butterflies in 

 myriads in powerful flight in a fixed direction gives to it an appear- 

 ance of objectivity which it may not possess in reality. It may be 

 nothing more than a static seasonal brood, not an actual migration 

 from one place to another. One is reminded of the story of the 

 Catopsilias heading towards Adam's Peak to dash themselves to 

 2 D 7(12)08 



