CHAPTER XI. 



OF THE CLASS OF MYRIAPODA. 



820. The Class Myriapoda is the lowest in which we meet 

 with articulated members, or distinct jointed legs, as well as with 

 an articulated body. These legs are intermediate in conforma- 

 tion between the more highly-organized legs of Insects, and the 

 simple bristle-like appendages possessed by some of the Anne- 

 lida ; and this is exactly the place to which we should refer the 

 animals of this class, from a regard to their general structure. 

 For, on looking at the form of their bodies, we see that they are 

 distinguished by a uniformity in the character of their segments, 

 nearly as great as that which prevails in the Annelida ; so that 

 an lulus (Fig. 511) might almost be likened to an Earthworm, 

 provided with a stiffer integument and with slender legs : 

 whilst, on the other hand, the adaptation of the respiratory 

 organs to breathe air with regularity and energy, the complexity 

 of the masticating apparatus, the possession of distinct eyes, and 

 many other characters, indicate their affinity with Insects ; in 

 which class, indeed, some Naturalists comprehend them. They 

 differ from insects, however, not merely in the absence of wings, 

 but in the great multiplication of the segments, which are nearly 

 always twenty-four at the least, each provided with a pair of 

 legs ; and also in the absence of any line of division between the 

 thorax and abdomen. As we have already seen( 797)> tnere 

 are certain Crustacea which bear a considerable resemblance to 

 them in regard to the equality of the segments, and general orga- 

 nisation ; but these are characterized by their branchial respira- 

 tion, and the number of their segments is usually much inferior. 



821. The covering of the body of these animals is firm, and 

 of a somewhat horny character, resembling that of many Insects. 

 The division into segments is very distinct ; a flexible membrane 



