LEPID OPTERA. 
81 
under side. The fly settles, clings to a twig, presses the tails of the under-wings— 
now folded together against it—and nothing hut an old withered leaf remains 
where hut just now was a gaudy butterfly. A species of the genus Heliconius, an 
insect avoided by birds on account of its bitter flavour, is closely mimicked by 
another butterfly of the genus Mechanitis. Though very sweet - flavoured, it 
escapes unmolested amongst its less agreeable companions. The mimicry involved 
in the feigning of death by many species of moths is, of course, protective. It has 
even been asserted that a specimen of the magpie-moth continued to feign death 
three hours after its head had been severed from the thorax. 
imago or Perfect If all the dangers noted above have been passed through with 
insect. impunity, in due time, at various seasons of the year, the perfect 
insects—butterfly, or moth, as the case may be—will emerge. These vary in size from 
12 inches or more in the expanse of the upper-wings to a quarter of an inch;—the 
latter being amongst the smallest moths, or Microlepidoptera. We have remarked 
that the body is divided into three distinct divisions, head, thorax, and abdomen; 
we must now shortly notice the various structures peculiar to each division. The 
first division of a lepidopterous body is itself divided into four 
Head. .... 1 r J 
main divisions. The occiput, next to the thorax; the epicranium, 
bearing the antennae; and, in some moths, the ocelli or simple eyes; the clypeus, 
lying in front of the epicranium, just on the mouth-parts, which latter themselves 
fall into at least five or six distinct structures; the proboscis, long, and capable of 
being rolled up beneath the labrum when at rest; the labrum, lying at the base of 
the proboscis, above ; the maxillary palpi (absent or rudimentary in the butterflies) ; 
the labial palpi, and rudimentary mandibles, aborted in many cases, complete the 
mouth structures. It is in the structure of the mouth-parts, perhaps, that the butter¬ 
flies and moths differ most from other insects, and more especially from the fact 
that the mandibles of the insects have in the Lepidoptera become modified into a 
long, spirally curled, retractile proboscis, composed of three distinct hollow tubes, 
soldered to each other along their inner margins. Indeed, it has much the appear¬ 
ance of a double-barreled gun, with a third tube lying below beneath the suture of 
the upper and larger pair. But it is with this latter alone that nutrition is imbibed, 
and it is supposed that the other pair may furnish air in addition to that obtained 
through the spiracular orifices along the abdomen. The ocelli, or simple eyes, 
resembling those of the larvae; the small eyes on the upper part of the head of 
bees and other Hymenoptera, as well as those of other Arthropods, such as we find 
to the number of from four to eight in the spiders, are not discoverable in the 
butterflies, but are present in the moths alone. The large compound eye, composed 
of numerous facets, is, however, present in both sections of the order, lying on 
either side of the epicranium, just below the point of insertion of the antennae. 
Whether they see nature with these “ as through a veil,” or appreciate every detail 
as we do ourselves, is a matter of speculation, but not easy of solution. The pair 
of thread-like, many-jointed organs, which take their origin from the side of the 
epicranium, just above and within the compound eyes, are amongst the butterflies, 
with the exception of the family Hesperiiclce, thread-like, and abruptly clubbed at 
the apex. In the latter family they are gradually thickened towards the end, 
which often terminates in a hook-like point. The moths, however, as their name 
VOL. vi. — 6 
