Page:The American Cyclopædia (1879) Volume IV.djvu/114

 106 CATERPILLAR a series of beautiful vignettes for Caro's Italian version of the ^Eneid. Going to Rome in 1809, he -painted historical, genre, and landscape subjects successively, and greatly modified the style which he had acquired at Paris. In 1834 he painted a "Resurrection of Christ" for the Luisenkirche at Charlottenburg near Ber- lin, a large work containing many figures. With this exception, his most celebrated paint- ings are landscapes. Of these, his views of Naples, Vesuvius, Sorrento, Salerno, and in Sicily, to which island he went in 1818, are considered the best. His works found their way over all Europe, and as they commanded high prices he became rich. In 1841 he was made a member and professor of the academy of Berlin. He left his fortune to be invested for the benefit of poor artists. CATERPILLAR, the common name of the lar- va? of lepidopterous insects, including butter- flies and moths. Caterpillars vary greatly in form and appearance, as may be judged from the fact that about 600 species are known in 1. Smooth Caterpillar (Asterias). 2. Hairy Caterpillar (Acnea). 8. Spanner (Geometra). New England alone, and probably many are yet unknown. The body is composed of 13 segments; the first constitutes the head, contain- ing the jaws and oral appendages; the second, third, and fourth form the thorax of the future insect, and the remaining ones make up the ab- domen. The head is rounded, and of a harder consistence than the body; on each side are six very small ocelli, or simple eyes, with a very convex cornea and a spherical crystalline lens, two short antenna?, and a mouth, with strong jaws moving transversely ; the mandi- bles are hard, for breaking up the food, while the maxilla) are soft and adapted rather for holding it ; in the mi&lle of the lower lip is a conical tube, through which issue the silken threads from which their nests and cocoons are made, and their suspensory fibres; a viscid fluid, enclosed in two long and slender bags, is poured out through the " spinneret " in a fine stream, and hardens hjto silk on con- tact with the air. The segments of the body are very nearly equally developed ; the second, third, and fourth have each a pair of tapering, jointed legs, covered with a shelly skin and ending with a little claw ; these are the rudi- ments or cases of the future limbs, and are the true organs of locomotion ; some of the other segments are furnished with soft, joint- less, fleshy, and contractile legs, called prop legs, which disappear with the larval condition, being only prolongations of the external cover- ing and shed with it, like the nails and claws of the higher animals ; the abdominal legs vary in number from four to ten, and are provided around the margin of the sole with rows of minute hooks capable of such direction as is necessary for a secure hold. The body is in some cases smooth, in others hairy, and even spiny ; these external appendages, whether for ornament or defence, are shed with the skin before the pupa state. Where the middle por- tion of the body is unprovided with feet, the caterpillar adopts the arched or looped manner of walking, so familiarly known in the common canker worm ; these species are hence called spanners, loopers, surveyors, and geometers; some, when in a state of repose, fix themselves by the hind legs only, and project in a rigid condition from branches, which they then much resemble in direction, form, and color; the power of remaining thus immovable for hours at a time must be due to a muscular force of which we have no idea in vertebrated animals ; the species which have eight to ten intermedi- ate feet walk by short steps, in a continuous worm-like manner. Some smooth caterpillars, as those of the sphinx moth (commonly called potato worm), have a spine or thorn upon the top of the last segment of the body, directed backward and curved ; though this looks like and has been considered an offensive or defen- sive weapon, its softness is such that it could inflict no wound. The larva? of some of the hymenopterous insects, as of the saw flies (tenthredinidce), resemble caterpillars both in form and habits; but these false caterpillars may be distinguished by their greater number of legs (18 to 22), and by the absence of the numerous hooks in their prop legs ; the larvro of other insects, having the same number of segments, are scaly and not soft and membra- nous. On each side of the body are nine oval apertures, spiracles, or stigmata, situated in the second, fifth, and following segments to the twelfth, provided with valves ; these commu- nicate directly with the internal respiratory organs, which are in the caterpillar branching tubes; in the perfect insect, the trachere are dilated into an immense number W vesicles permeating every part of the body. The intes- tine is short and straight. The nervous system is a series of ganglia connected by chords, one for each segment, the greater part of it in the perfect insect being concentrated in the head and thorax. Caterpillars vary greatly in size ; the mean may be taken at an inch, those much exceeding this being large, while those much below it may be considered small ; those which have only eight feet in all are the small- est, and are generally the moths' caterpillars. The size of a caterpillar compared to that of the egg is very great, and the rapidity of its