PIERID.E. 135 



claws of the tarsi bifid ; pulvilli and paronychia generally present. 

 Coloration in the vast majority chiefly or partially white, whence 

 the forms in the family have acquired the distinctive appellation 

 of " the whites." 



A summarized account of the habits of the Indian Pieridce in 

 the larval state has been given by Messrs. Davidson, Bell, and 

 Aitken in the ' Journal of the Bombay Natural History Society,' 

 vol. x, 1896, p. 569. I venture to quote it in full here : 



" All the larvae of this subfamily lie, when full-grown, on the 

 upperside of the leaf, and when solitary (some of them are grega- 

 rious) along the mid-rib, coating the leaf where they lie with a 

 bed of silk. The eggs are generally laid singly on the upperside 

 of the leaf or on young shoots ; exceptions to this are *Teracolus 

 amata, J'abr., Appias liippoides, Moore, and Delias eucharis, Drury 

 (this last is aberrant also, in that the eggs are laid on the under- 

 side of the leaf where the larvae herd together), Behnois mesen- 

 tina, Cramer, Terias silhetana, Wallace, which lay their eggs in 

 clusters ; the larvae of these when young are gregarious, but 

 generally when full-grown separate where the food is plentiful." 



Of the eggs these authors say : " The egg of the subfamily is 

 spindle-shaped, standing on one end, and is also more or less 

 strongly ridged longitudinally and striated finely transversely ; in 

 colour it is generally pure white, turning to yellow or orange ; 

 that of Nychitona (Leptosia) xiphia, Fabr., is blue and that of 

 Haphina blotched with red." 



The remarkable habit in butterflies of this family of migrating 

 in large numbers together, has attracted the attention of travellers 

 and naturalists in all parts of the world. No satisfactory explana- 

 tion of the reason for these migrations has yet been offered. It is 

 a wonderful sight the clouds of butterflies, chiefly Pierids and by 

 far the greater number of them belonging to the genera Appias 

 and C'atopsilia, stream past for hours at a time, all going in one 

 direction, and in all instances that I have witnessed flying against 

 the Avind. One effect, of these migrations is wide dispersal and 

 the consequent breaking-down of distinctions between local races, 

 for any little peculiarity due to isolation and environment stands 

 little chance of perpetuation, swamped as it is by the continual 

 arrival of forms from other localities. A long series of Appias, 

 for example, from widely-separated localities shows variation to a 

 limited extent, and that unstable in itself and scarcely to be 

 denned in words. 



Much attention has been paid to the phylogeny of the Pieridce, 

 perhaps more than to that of any other group of the diurnal 

 Lepidoptera. In butterflies, however, as in all living things, 

 specialization has taken an irregularly-radiating rather than a 

 linear course, so that any arrangement of genera in sequence can 



* In this work the names of the butterflies mentioned stand as Colotis 

 amata, Fabr., Appias hippo, Cramer, Delias eucharis, Drury, Anaphceis mesen- 

 tina, Cramer, Terias silhetana, Wallace, and Leptosia xiphia, Fabr. 



