92 INTRODUCTION TO ZOOLOGY. 



observe one of their members with the naked eye — which may 

 be the utmost stretch of unassisted vision — with the micro- 

 scope it first appears jointed, or composed of several pieces 

 articulated together; employing a higher magnifier, it appears 

 fringed with long hairs, which, on further scrutiny, gain a 

 sensible diameter, and seem to be themselves fringed with 

 hairs still more minute; many of these minute parts are evi- 

 dently jointed and perform sensible motions; but what idea 

 can we form of the various muscles which put all these parts 

 in movement, of the nerves which actuate them, and the ves- 

 sels which supply them with the nutriment essential to their 

 growth and daily expenditure, all of which we know from 

 analogy they must possess?'" 



Class IV mSECTA— INSECTS. 



" The insect youth are on the wing, 

 Eager to taste the honied spring. 

 And float aniid the liquid noon : 

 Some lightly o'er the current skim, 

 Some show their gaily-gilded trim, 

 Quick-glancing to the sun." — Gray. 



" We now come to a class of Articulata in which," says 

 Professor Owen, " the highest problem of animal mechanics is 

 solved, and the entire body and its appendages can be lifted 

 from the ground and be propelled through the air. The 

 species which enjoy the swiftest mode of traversing space 

 breathe the air directly; but their organs of respiration are 

 peculiarly modified, in relation to their powers of locomotion."* 



Fig. fiS. — SCOLOPENDRA. 



NoTK The total number of Irish insects at present known is abont 



3850. Vid. note by A. II. Ilaliday, Esq. appended to the report on 

 the Fauna of Ireland, by William Thompson, Esq. Proceedings British 

 Association, 1843. 



• Lectures, page 192. 



