BUTTERFLIES. 133 



dichroic ; one form is green, red and golden ; the other is -white, black 

 and golden; the latter is very beautiful. 



118. Atella ALCIPPE, Cramer. 



Appears to occur only in the outer valleys debouching on to the 

 plains, such as Sivoke, from whence the natives bring it in considerable 

 numbers. I have never seen it alive in Sikhim. It occurs almost 

 throughout the year except in the winter. 



119. Cethosia CYANE, Drury. 



Common in Sikhim from April to December at 5,000 feet and 

 below. The larvte of this and the next two species feed in such 

 numbers on the common white and blue passion-flower as to become 

 a veritable nuisance. 



120. Cethosia biblis, Drury. 



Also common, occurs up to 7,000 feet, and is found almost 

 throughout the year. It is found in Western and Central China. 



121. Cynthia erota, Fabricius. 



Common from the Terai to 6,000 feet elevation almost all the year 

 round. I have bred this species, Cethosia hiblis, Drury, and C. cf/ane, 

 Drury, from larva? taken in numbers from the same passion-flower 

 {Passiflora sp.), in October. The specimens of C. erota which emerge 

 in the early spring from larvaj fed up in the late autumn are much 

 smaller, and the females much lighter coloured, than the later broods of 

 the year. In this species, as indeed in most tropical and subtropical 

 species of butterflies, brood succeeds brood in regular succession 

 throughout the year. These broods are more or less interrupted in 

 the plains of Northern India where the rainfall is scanty, the intensely 

 dry weather of the early summer acting like the cold winter of other 

 regions in entirely stopping the further development of the sjDecies in 

 any stage of its existence; but as soon as the rain falls at the burst of 

 the monsoon, butterfly life resumes its activity, and fresh broods are 

 rapidly developed. Single-brooded species are excessively rare in 

 tropical and subtropical India, and my impression is that their occur- 

 rence at all arises fi'om the fact that the larva? have very weak jaws, 

 and being able only to eat the youngest leaves of their respective 

 food-plants. Single-brooded species in India, as far as I know, always 

 occur in the early months of the year, when usually deciduous trees 

 assume their new annual covering of leaves. The butterflies emerge 

 from hibernated pupa? just before the young leaves are developed, lay 

 their eggs on the leaf-buds or young twigs, the larva? quickly emerge, 

 feed up rapidly on the juicy and succulent young leaves, turn into 

 pupae in the course of a month, and so remain for 1 1 months till the 

 following spring comes round, when they emerge as butterflies, and 

 the cycle of their existence is completed. 



K 2 



