8 ntscKimoN or i'akt>. 



The PXtrrtwl ct>vrring of liuieclit L<t (jiillr hnni : tt la cnll«-«l tntrgvmmt, or cruji, and 

 •appIlM chi< |>Uc«' of the iiitrrual »krlfU»n, ntnl Is Ihr imrl U> which the luUAcleji are at- 

 tachitl It I--* !»«>niewliat hi«riiy, i>r wirnwuji, Ixit varies considerably in this re«i)ect in the 

 (litrrmit <i|>«fle^ : in rertniii >>c«-tlr.t It is hiir<l and inflexiMe ; whlh- in others, it is soft and 

 •jiiile llexli.le It rrsend'les tile true skin of iminiult in it> divisihilily into thn-*- ln>ers, an 

 upidennis, a n-te nnn*o^uni,an<l a h-atlu-ry tunic calli-«l the ronum or drrmu, the true skin. 

 This outer InteRununt is coni|»>M'd tlnniically of |>ho>]>hate of lime and nwiniesla ; hut, 

 what i^ interesting, it is fouuil t" contain a jx-cullar suKstance. teriue<i rAi/inr, which is 

 insoluMe in |K>ta>h. I'hosphate of inai, allxumn, and a |xculiar coloring matter, are also 

 amoni; the sulistanres comiH»sinj; this integument. 



The sliajx-of the hea»l is varialde, hut the sjiherical form l>ndominat<-s. Tlie integiuneut 

 forms a kind of box, with an ajK-rturc in front, through which the organs uf the mouth 

 may Im> thrust. Tlie jtontcrior juirt furnisht'S a jdace and attachments for the miLscles which 

 move the hea<l u|>on the thi>ra\. The eus are large, u>ually, ami occupy the lateral i.arts 

 of the lujid. The exteriuil parts uf the liead have receive«l diflV-reiit names. The rfricranium 

 is that jx-rtion which extemis fn.m the eyes >>ackwards. In front of the epicranium, is the 

 forehead. The clypciu Ls iheniarnin in front aU.ve the mouth. S.metimes the whole region 

 in fr\.>ut of the eyes is calletl the face. The inferior i>artsof the Im.x enclosing the head has 

 also Its siiac*"*, which have receiv»-<l distinct names, as guln^ur thnwt, which lies imme- 

 diatoly behind the margin uf the lower lip, and extends back to the prvthorax. The chei-ks 

 aro situated uix.>n the sides of the head, from the eyes downwards to the moulli. The an- 

 tounie ari> situated Utween the angle of the niouth and the ejc* : tliey have a sul»glol)uM' 

 joint at the l>ai«', ujx'n which they move, and which is placed in a kiml of socket ; this is 

 •Oinetiim-s calleil a toiulut. 



The m>'Ulh. as may W suppos«il, is constructe<l si as to an>w«r the ends designed, and 

 it is either suctorial or manducatory, masticating : if the fotsl i> fluiti, it i> suctorial; if 

 *jlicl, it has jaws for mastication. In tlie mandibulate or masticating, there is jHrfcct free- 

 dom of motion ; in the suctorial or haustellale (huustillafa), the jmrts are more or less 

 •ulderctl together, so as to form a tuU* for the transmission of fluitls. The terms hausttUata 

 •nd tnandibulata apply, thcrefi»re, to two great classes of Insects, one of which sul>sist5 on 

 the juices of plants and animals, which the) obtain by suction; the others, the masticating, 

 «uU«isl on xdid •«ul>slances. Animals destim-*! to obtain fo<xl by modes so apparently distinct, 

 fiirnL'.h many distinctive characters of inij)t..rlance. The /utriyia is the most anterior l>art 

 Miuu from al>ove ; it covers the mouth, and is uniteil by a membranous hinge to the cly- 

 pcas ; it is employed in retaining the fo.«l in the moutli during mastication ; it is, there- 

 fore, a true upi>«r lij>, but of a variable form. Mastication is jMrforme<l by the mandibltt, 

 which are two strong jaws that move laterally, and consist of w«tlge-shaj««tl or triangular 

 pieces more or less elongated, and placwl imme«!iately IhIow the labruni. These organs are 

 al*i c&Iled upper Jaws : they move like the blade:) of srissa^rs. Their inner edge is frr- 



