LEPIDOPTEWA. 467 



cal, soft, variously coloured, sometimes naked, arid sometimes co- 

 vered with hairs, tubercles and spines. It is composed of twclvo 

 segments or annuli, exclusive of the head, with nine stigmata on 

 each side. Their head is invested with a corneous or squamousi 

 dermis, and presents on each side six shining granules, which ap- 

 pear to be ocelli; it is also furnished with two very short and conical 

 antennae, and a mouth composed of strong mandibles, two maxillae, 

 a labium and four small palpi. The silk they employ is elaborated 

 in two long and tortuous internal vessels, of which the attenuated 

 superior extremities terminate in tlie lif>. A tubular and conical 

 mammilla is the spindle through which the threads are spun. 



Most caterpillars feed on the leaves of plants; some gnaw their 

 flowers, roots, buds and seeds; others attack the ligneous or hardest 

 part of trees, softening it by means of a fluid which they disgorge. 

 Certain species attack our woollens and furs, thereby doing ys much 

 injury: even our leather, bacon, wax and lard are not spared by 

 them. Several confine themselves exclusively to a single article of 

 diet; others are less delicate, and devour all sorts of matters.(l) 



Some of them form societies, and frequently live under a silken 

 tent, spun by them in common, which even shelters them during the 

 winter. Several construct sheaths for themselves, either fixed or 

 portable. Others make their abode in the parenchyma of leaves, 

 where they form galleries. The greater number are diurnal. The 

 others never issue forth but at night. The severity of winter, so 

 fatal to almost all Insects, does not affect certain PhalaenaB, which 

 only appear in that season. 



Caterpillars usually change their skin four times, previously to 

 passing into the state of a nymph or chrysalis. Most of them 

 spin a cocoon in which they enclose themselves. A frequently red- 

 dish liquor which lepidopterous Insects eject at the moment 

 of their metamorphosis, softens or weakens the extremity of the co-* 

 coon, and facilitates their exit; one of these extremities also is ge- 

 nerally thinner than the other, or presents a favourable issue by the 

 peculiar disposition of the fibres. Other caterpillars are contented 

 with connecting leaves, particles of earth, or of the substances on 

 which they have lived, and thus forming a rude cocoon. The chry- 



(1) One of the most evident proofs of the divine providence is the peK 

 fect coincidence of the appearance of the caterpillar with that oi'ihe plant 



on which it is to feed. 



