THE BUTTERFLIES OF CEYLON. 83 



from one species which we knew as K. inachus. It extends over 

 hundreds of miles of country from Tenasserim in the east to the Murree 

 Hills in the west. The climate of this extensive area is naturally 

 extremely diversified and the colouration of the butterfly ranges from 

 an Oxford blue in the east to an almost Cambridge blue in the west. 

 The former colour is produced by continuous heat and heavy continuous 

 rainfall. In Sikhim and Nepal, the heat and rainfall are not continuous 

 throughout the year, the late winter and spring months being dry and 

 somewhat cold in the localities frequented by Kallima, though both 

 heat and rainfall in the lower vnlleys are very great in the summer 

 months ; such a climate produces typical K. inachus. In the Western 

 Himalayas there is bright sunshine, and though the heat is considerable 

 it is nothing like that of Sikhim, and both it and the rainfall are far less 

 than further east. This climate produces K. kuegelii. In the neigh- 

 bourhood of Mussoorie in the Dehra-Dun both the dark and light- 

 blue forms occur, from which I infer that the climate is not sufficiently 

 pronounced either way to produce a permanent form, but permits both 

 to flourish. A somewhat similar pale form of K. limborgii occurs, 

 together with the type in the Shan States where the climate is more 

 temperate and the rainfall less than in Tenasserim where limborgii 

 only is found. The climate of the Indo-Ceylon region is in many 

 respects similar to Lower Burma, there being rain during the greater 

 portion of the year and continuous tropical heat, which two factors 

 together have probably caused that intensity of colouring which dis- 

 tinguishes the butterflies of this tract of country. Similar causes have 

 in all probability produced the still greater amount of colouring which 

 distinguishes the local races of Ceylon butterflies from their neigbhours 

 across the Gulf of Manaar. But to ascertain with any hope of success 

 the exact amount of extra rain and heat* necessary to develop these 

 forms seems at present hopeless. 



Some assistance may be derived from the study of the seasonal 

 changes to which many Ceylon butterflies are subject. In some parts 

 of the world, as in South Africa or the plains of Panjab, the same 

 climate exists for several weeks or months over several thousand 

 square miles of country, and an insect captured in Peshawar in June, 

 would not necessarily vary from one captured in Mooltan in the same 



• If the local race of Elymnias lutescens has been produced in less than 50 years, the 

 time required might not be so great as is generally presumed. 



