144 
LEPID OP TUB A INDICA. 
the sombre markings in this group are instances of protective resemblance, the under¬ 
side of the hindwings being marbled or mottled with darker and lighter colours, in 
such a way as to render the insect very difficult to see when alighted, for instance, 
upon a gray rock. That this is its purpose, is indicated, not only by the invariable 
habit of insects of this subfamily to alight with closed wings, showing only their 
under surface, but their very common trick of immediately dropping the front wings 
into concealment between the hinder pair, and also of tipping over to one side and 
resting in a half reclining posture, the gray wing against the gray rock. 
“ The caterpillars may be readily recognized by the peculiar bifurcation of the 
terminal segment of the body ; they are almost invariably clothed only with a 
short but coarse pubescence arising from papillm so numerous as to give a shagreened 
appearance to the skin, and longitudinally striped with continuous or broken bands 
of colour. Mr. Distant rightly considers this a form of protective colouring, and even 
looks upon the forked tail as in some measure protective, and on type of larva as a 
‘very primitive form. 3 He remarks (Khopalocera Malayana, p. 37) that ‘they are 
almost all feeders on various grasses, to which their green coloration and markings 
assimilate them, thus affording a good example of “ protective coloration.” 5 In an 
evolutionary sense there are also ample grounds for considering them as exhibiting a 
very primitive form. Dr. Weissmann ( c Studies in the Theory of Descent,’ Engl, 
edit.) has made the most profound and philosophical study of larval characters, princi¬ 
pally as found in the Sphingiclce , a family which strongly exhibits more or less 
specialized larval markings. ITe considers the oldest Sphinx larvae as being without 
markings and probably protected only by adaptive coloration and a large caudal 
horn, &c. It is at least probable that the bifid tails of the Satyrince fulfil an analo¬ 
gous protective function with this caudal horn in the Sphingiclce , or with the forked 
horn at the tails of the larvse of some genera of moths. With the next stage of 
Sphingid evolution, where the larvse have become longitudinally striped, we may 
almost apply Dr. Weissmann’s very words to the Satyrince :—‘ The caterpillars thus 
marked must have been best hidden on those plants in which an arrangement of 
parallel linear parts predominated ; and we may venture to suppose that at this period 
most of the larvse of the Sphingidse lived on or among such plants (grasses).’ 
“ The caterpillars eat slowly and are very long in attaining maturity; and as 
the egg and chrysalis states are usually longer than common, the species of this 
group are almost without exception single brooded,* and, in the genus QEneis, some 
species are supposed to take two years to complete the cycle of growth. So far as 
is known, the larvae feed only on grasses and sedges (the only exception known to¬ 
me is the European Coenonympha tiphon , the caterpillar of which is said by Merrill to 
feed on Rhynchospora, one of the Cyperacese). It is probable that the larvse of 
# See subsequent remarks on “ Seasonal Dimorphism ” in this subfamily. 
