IXSECTA. 



INSF.CTA. 



MO 



B, and remain* to enoaee the proper akin of the pupa that U formed 

 beneath it; and in addition to this, it i* frequently protectotl by a 



. 



to 



in addition 



, Uw construction of which wai the but act of larval 



The duration of UM papa condition, and the rate at which the 

 take place, vary considerably in different cases 



nnn, uuect* remaining in thi* *UU for yean, while other* pea* 

 through it in a few dayi or boun ; in both oases however we perceive 

 that an important influence fa exerted by external temperature. As 

 UM *UU of the pane, it one of rapid transition it cannot be aaid to 

 have any charactcrietio organisation. The assumption of the imago, 

 or perfect type of beaut life, u alwaya marked by an exuviation of 

 the integument which covered the pupa; and with thi* are cast off 

 all the vestiges of the organ* peculiar to the larva state, while the 

 wing*, the true leg*, the compound eyes, the antennie, the complete 

 macticating or mctorial apparatus, and many other organs are tiow 

 revealed for the firat time in all those whose pupa condition was 

 inactive. The wing* however are seldom ready for use at the time 

 of UM insect's emersion from the pupa-case, being usually soft and 

 moUt, banging loosely at the sides of the body, and having none of 

 that rigidity which U requisite to give them power of serving us 

 organ* of impulsion in the air. It is not until the insect has forcibly 

 injected the trachea with air by taking several full inspirations, and 

 then making an expiratory effort whilst the spiracles are closed that 

 UM wing* are expanded; they then soon become dried up by exposure 

 to the air, and by the cessation of the circulation which previously 

 took place within them, and from that time they are the chief instru- 

 ment* of locomotion in all insects in which they are fully developed. 

 The nutritive apparatus of the Imago is far leas developed relatively 

 to the muscular, nervous, and sexual organs than it is in the preceding 

 conditions ; and it* subordination to the offices of these is shown by 

 the fact that many insect* take no food whatever after their last 

 change, the sole purpose of their existence in their perfect state being 

 the propagation of the race by the generative process. In many 

 instance* the duration of the imago state is very brief, even when 

 that of the preparatory periods has been very long, as in the case of 

 the BfJttmera (Day-Fly), which usually dies in a few hours after its 

 but change ; although the term of its previous life as a larva and an 

 active pupa ha* not been less than two or three years: and even 

 when the length of the life of the perfect insect is much greater, as 

 in bee*, wasp*, etc., it seems to have a special relation to the nurture 

 of the oftspring, which are tended and supplied with food during the 

 whole of the larva state. In the Ant tribe the neuters do not acquire 

 wings ; and some of them, which are two or three times the size of 

 the rest, and are somewhat differently formed, are characterised as 

 'soldiers,' their special office being the defence of the nest rather 

 than the nurture of the young. Among the Termite* (White Ants) 

 however the soldier* appear to be pupa arrested in their development, 

 whilst the 'worker*' have the character* ef permanent lame. In the 

 Apterous orders of insect* we find some tribes undergoing a regular 

 metamorphosis, which is complete in every respect save the non- 

 development of the wing*. Thus, the larva of the Pulex (Flea) are 

 footless worm*, which afterwards pas* into the pupa state, spinning 

 for themselves silken cocoon ; in this they remain inactive for about 

 twelve days, after which the imago comes forth, having the rudiment* 

 of wings attached to the second and third segment* of the body, 

 though without any proper distinction of thorax and abdomen. The 

 Ptdtcmltu (Louse), t'odura (Spring-Tail), and some other Aplera how- 

 ever undergo no metamorphosis, coming forth from the egg in the 

 condition in which they remain all their lives, and this being far from 

 the type of the perfect insect (Carpenter, ' Principles of Physiology.') 

 We now come to speak of the classification of Insects. As the 

 various orders of insect* are noticed under their respective headings, at 

 present w* shall confine ourselves to the arrangement of these orders. 

 The order* of insects have been so variously arranged by different 

 author*, that to give an outline of the views even of the more cele- 

 brated would occupy much space ; we will therefore select the moat 

 distinguished of these systems : Fintly, that of Linneou*, whose sub- 

 division* are founded upon the substance and position of the wings ; 

 next, that of Fabriciu., when the part* of the mouth have been 

 elsetrf in the divuion of thi. class into orders; then that of Bur. 

 Mister, where no particular part or character has been chosen, but 

 where the orders art established upon an aggregate of characters: and 

 lastly, that of Mr. Wntwood. 

 The order* of insect* are thu* characterised by Linnnus : 



Superior wings crustaceous, with a straight 

 suture ..... 



Superior wings semicrustaceotu, incumbent 



All the wing* with scales . 



All the wing* membranous, tail unarmed 



All the wing* membranous, Uil aculeate 



Two poisen in the place of the posterior pair 

 of wings . . , 



Without either wings or elytra . 



Insect* are divided by Fabricius into 



L Insect* with Biting Mouths. 

 SUuOttrala, Maxilla free, uncovered, and palpigerou*. 



C'oleof/Ura, 



J/emiptera. 



Lepidopttra. 



Neuroptera. 



J/ynenoptera. 



Hipltra. 

 Aptera. 



2. UloKota, Maxilla covered by an obtuse galca or lobe. 

 (OrfAopMro.) 



5. Synutata.~ Maxilla geniculate at the base, and connate with the 

 labium. (\europtfra, Ac.) 



4. Piaata. Maxilla corneous, compressed, often elongate. 

 (Bymaupttra.) 



6. Odonala. Maxilla corneous, toothed ; two palpi. (Libell*l<r.) 



6. Mitotata. Maxilla corneous, vaulted, not palpigerous. 

 (Myriopoda.) 



7. Unogata. Maxilla) resembling scissors. (Aracknida, part) 



8. Potyyonata. Palpi mostly six ; many maxilla; within the labium. 

 (Itopoda.) 



9. KUiitOffnatha. Many maxilla! without the labium, closing the 

 mouth. (Brachyurous Decapod Criulacea.) 



10. Exochnata. Maxilla: many without the labium, covered by 

 palpi. (Macrurous Decapod Cnutacea.) 



II. InaecU with Suctorial Mouths. 



11. Glouata. Mouth with a spiral tongue between reflexed palpi. 

 (Lepidoptera.) 



12. Kyngota. Mouth with a rostrum having a jointed sheath. 

 (Htmiptcra, Latr.) 



13. Anttiala. Mouth with a hauatellum without joints. (Dipkra, 

 Anoplura, and Trachean Arachnida, Latr.) 



BurmeUter'a System. 

 L Jiuecta Amelabola. 



The larva resembles the perfect insect, yet it wants wings, if the 

 perfect insect be winged ; the pupa in this case has iU rudiments. 

 It runs about and eats. 



a. With sucking mouths, which consist of four fine seta! lying 



in a sheath ; palpi are wanting ; four biliary vessels, and 

 generally a free prothorax. 



Order 1. Hemiptera. 



b. With mandibulate mouths ; mandibles and maxilla; distinct, 



the latter having palpi, and generally distinct large 

 superior lip. 



a. Four unequal wings; the anterior pair leathery, or like 

 parchment, the posterior pair folded longitudinally, and 

 also once transversely; prothorax always free; many 

 biliary vessels. 



Order 2.Orthoptera. 



ft. Four generally equal and rarely unequal wings, never folded, 

 or sometimes none at all. In the first the nervures are 

 usually reticulated, and there are generally many biliary 

 vessels; in the latter case there are four biliary vessels 

 attached to the intestine ; prothorax sometimes free, some- 

 times not 



Order 3. Dictyoptera. 

 ILIiuecta Mctabola. 



The larva consists of thirteen segments, either with or without legs ; 

 the pupa is inactive, or, if it moves, it takes no food. 



a. Four equally large or equally long wings with reticulated 



nervures ; mandibulate mouths ; few biliary vessels, rarely 

 more than eight ; prothorax always free. 



Order 4. IVctiroplera. 



b. Wings alwaya unequal, the posterior pair sometimes wanting, 



rarely all. 



a. Mouths adapted to sucking. 



a a. Instead of posterior wings there are pediculated knobs ; 

 yet the wings are sometime* wholly wanting ; four 

 biliary vessels ; larva without feet ; a soft proboscis 

 with several seta; and a pair of palpi ; prothorax 

 not free. 



Order 5,Diptera. 



b b. Four wings generally covered with scales ; six biliary 

 vessels ; larva with feet and a distinct head ; maxillaj 

 forming n spiral tongue ; prothorax nut free but 

 small, and closely connected with the mesothorax. 



Order 6. Lepidoptera. 

 ft Mouths with distinct biting mandibles. 



a a. Four naked wings travenwd by ramose tiervures ; larva; 

 generally without head and feet, but sometimes with 

 both ; many biliary vessels ; prothorax not free. 



Order 7. JJymenoptera. 



b b. Anterior wings in the form of horny elytra ; larva; with 

 head, with or without feet ; four or six biliary 

 veeseU ; prothorax always free. 



Order 8. Coleoptera. 



The first and second of the above classifications are by no means 

 natural, nor were they intended to be so by their respective authors. 



