LEPIDOPTERA. 81 



under side. The fly settles, clings to a twig, presses the tails of the under- wings 

 now folded together against it and nothing but an old withered leaf remains 

 where but 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 

 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 Hesperiidce, 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 



