604 



INSECTA. 



Kig. li;6. — Caterpillar and Chrysalis of the Magpie Moth. 



their peculiar mode of walking. Seizing fast hold of the objects on which they are stationed 

 with these six fore-legs, they elevate the intermediate segments of the body into an arch, until 

 they bring the hind-feet close to the others ; these they disengage, and, retaining hold with 



the hind feet, thrust forward the body to 

 its full length, and then recommence the 

 same manoeuvre. Many of these Looper- 

 caterpillars resemble, in their mode of 

 standing, fixed for a great length of time 

 only by their hind legs to twigs, as well as 

 in their form and colours, small pieces of 

 stick. Such an attitude necessarily requires 

 a prodigious muscular force, and Lyonnet 

 has, in effect, discovered that the caterpillar 

 of the Goat Moth posseses 4041 muscles. 

 Some Caterpillars with fourteen or sixteen 

 feet, (some of the intermediate membranous 

 legs being, however, smaller than the others,) have been named Semi-geometers. The mem- 

 branous feet are mostly terminated by a more or less perfect coronet of little hooks. 



The body of these larvre is generally long, subcylindric, soft, variously coloured, sometimes 

 naked, and sometimes hairy, tubercled, or spined, and consists of twelve segments, exclusive 

 of the head, with nine spiracles on each side ; the skull is horny or scaly, with six small 

 granular shining points, which seem to be ocelli, on each side : it has moreover two very short 

 conical antennae, a mouth composed of a pair of strong mandibles, two maxillae, a labium, 

 and four small palpi ; the silky material which it uses is elaborated in two long, tortuous, 

 internal vessels ; a tubular and conical point, situate at the tip of the labium, is the spinneret, 

 whence the silk is discharged. The majority of Caterpillars feed upon the leaves of vegetables; 

 others devour flowers, roots, buds, seeds ; others eat the hard and solid parts of the wood ; 

 this they soften with a secretion which they discharge from the mouth : certain species de- 

 stroy our woollen cloths, stuffs, furs, &c., and are the most obnoxious of our domestic insects ; 

 others feed on grease, fat, bacon, wax, &c. ; many feed upon a single material, but others, less 

 delicate, attack different kinds of plants. One of the most striking instances of providence 

 is the perfect coincidence between the appearance of the Caterpillar and the vegetable upon 

 which it is destined to feed. Some kinds of Caterpillars are social, and often live together 

 under a kind of tent of silk, which they spin in common, and which serves them as a defence 

 against bad weather ; many fabricate cases, either fixed or portable ; some are lodged in the 

 parenchyme of leaves, where they make galleries ; the greater number however delight in 

 daylight ; others, on tlie other hand, only come forth at night. Winter, notwithstanding its 

 rigours, so uncongenial to nearly all insects, is the period when some moths make their appear- 

 ance. Caterpillars generally moult four times before passing to the chrysalis state. The majority 

 then spin a cocoon in which they are inclosed ; a kind of meconium or red liquid, which these 

 insects discharge at the moment of their final transformation, softens one end of the cocoon, 

 and allows the escape of the moth. Generally one end of the cocoon is weaker, or even fitted by 

 the arrangement of the threads for the escape of the insect. Other Caterpillars merely con- 

 tent themselves with attaching together leaves, or particles of earth, &c., with silken thread, 

 thus forming a rough kind of cocoon. The Chrysalides of diurnal Butterflies are ornamented 

 with golden spots [whence their name of Aurelia; or Chrysalides], and are naked, and fixed 

 by the posterior extremity of the body ; these Chrysalides are of the peculiar kind which 

 Linnajus termed Pwpa oi^ecia, and which are mummy-shaped; the sheaths of the feet and 

 antennae being fixed. Those of many species, especially of Butterflies, are hatched in a few 

 days ; and thus there are two broods of these in a year. But in respect to others, these Cater- 



