INSECTA. 801 



All these as well as the scorpion, are produced perfect from the 

 parent, or the egg; and to undergo no changes after their first expulsion 

 They are-seen of all sizes; and this is a sufficient inducement to suppose 

 that they preserve their first appearance through their whole existence. It 

 is probable, however, that, like most of this class, they often change their 

 skins; but of this we have no certain information. 



CLASS IX. — INSECTA. 



Articulated animals ivith six legs, respiring by means of trachea ; head distinct 

 from the thorax ; tivo antenna:. 



This branch of science named Entomology, (from evxofiov, an insect, and 

 loyog, discourse,) including the most numerous class of organized being?, 

 has but lately risen into merited consequence. The use of insects, indeed, 

 in the economy of nature, was not likely to be estimated by men in the in- 

 fancy of society, to whose wants or conveniences they were apparently little 

 calculated to afford any addition. To some tribes, however, attention must 

 have been early directed, ( „, account of the ravages their united myriads 

 enabled them to perpetrate ; and others were early noticed as the industrious 

 collectors of a species of food which man has long converted to his use. 



The term Insecta is derived from the Latin in, into, and seco, I cut, from 

 the body having the appearance of being cut or divided into segments; and 

 a term of the same meaning, evmfta, (ev and refivta,) was used by the 

 Greeks. 



Linnaeus, whose powerful genius enabled him, in this, as in other branches 

 of natural history, laid the foundation or arrangements, from which all that 

 has since been done has emanated. 



The characters upon which Linnseus founded his arrangement, were 

 chiefly the wings, and hence his system has been called the alary system. 

 The class Insecta, of Linnseus, however, as it stands in the twelfth edition 

 of his Systema Natura, included the Crustacea and arachnides. He divides 

 the whole into seven orders, viz. 



I. Coleoptera, (from xolebg, a sheath, and meobr,a iving.) Wings four. 



the upper ones crustaceous, with a straight suture. 

 II. Hemiptera, (from r[iuav, half, and nreobv.) Wings four, semicrusta- 

 ceous, incumbent. 



III. Lepidoptera, (from Xenl;, a scale, and ■msobv.) Wings covered with 

 imbricated scales. 



IV. Neuroptera, (from vZvqov, a chord or string, and nxegbr.) Wings 

 membranous, Avith ribs or nerves : anus unarmed. 



101 



