COM PAIUTI VE AN' ATOM Y. 



337 



CO.Ml'AKATIVE ANATOMY. X. 



INSECTA. 



THE remaining throe classes of the articulated animals which 

 we have yet to describe namely, the Crustacea, Ara<')mi<la, 

 ami Innecta are collateral ^ruupi. Each has occupied the 

 highest position in the estimation of different classifiers. Each 



claim for the Crustacean* * oertain kind of superiority for them; 

 but wo find in the class Insecta the greatest development of 

 those peculiar excellences for which the whole articulate branch 

 is noted. The great characteristic of the Articulate! is their 

 external skeleton, and the adaptation of this to the purposes of 

 locomotion is, so to ipeak, the aim of this sub-kingdom. Other 

 organs and systems of organs are elaborated in an unsteady 



VL 



I. PBIVET HAWK MOTH (SPHINX LIOUSTRI) : a, CATEBPILLAB ; b, PUPA ; o, IMAGO. II. COMMON WASP (VESPA, : a, LARVA ; b, PPPA ; e, IMAGO. 



III. tlNDER-SIDE OP HEAD OF BED-BUO (ClMEX LECTULARIUS), WITH LOWER LIP BEHOVED (MUCH MAGNIFIED). IV. BEETLB WITH DOB3AL 

 INTEGUMENTS BEMOVED TO SHOW VISCEBA. V. BEE. VI. PARASITICAL INSECT SEEM BT TRANSMITTED LIGHT, ASD HIGHLY MAGNIFIED JO 

 SHOW TRACHEAL SYSTEM. 



fiefs, to Nos. in Figs. III. 1, lab rum, or upper lip ; 2, 2", roots of the mandibles ; 3, 3", roots of tbo maxillm ; 4, mandibles and luaxillso com- 

 bined into a piercer ; 5, antennae ; 6, 6, eyes. IV. 1, oesophagus ; 2, gizzard ; 3, stomach ; 4, entrance of the secreting organs ; 5, small 

 intestine; 6, large intestine; 7, ovaries; 8, sperm otheca ; 9, accessory glands; 10, common cloaca. V. 1, oesophagus; 2, crop; 3, 

 stomach ; 4, entrance of the secreting organs ; 5, small intestine ; 6, large intestine ; 7, common cloaca ; 3, ganglionio chain. 



possesses forms whose simplicity of organism and general in- 

 feriority of structure make the comparison of them with the 

 highest members of the other groups, with any idea of rivalry, 

 absurd. Each class, too, culminates in organisms whoso varied 

 parts and elaborateness of detail seem to place them at an ele- 

 vation beyond which it seems impossible to mount. In many 

 respects, as in their respiratory and circulatory systems, the 

 spiders seem to show an advance upon the Insecta ; while their 

 larger size and the greater complexity of their nutritive organs 



48 N.E. 



and fluctuating manner, sometimes appearing to bo degraded, 

 or altogether altering their type, as we proceed from ono order 

 to another ; but the perfection of the external investment, and its 

 better adaptation to the most efficient kind of locomotion, is 

 seen in every upward step wo make in our classification. And 

 it is in tho class Insecta wo find such marvellous finish and 

 efficiency in this port of the organism as to fill not only the 

 naturalist, but even tho casual observer, with wonder. The 

 strength and beauty of the elegant body and sculptured limbs 



