GENERAL CHARACTERS OP MYRIAPODA. 287 



the similarity in the character, of the segments. The Myria- 

 poda cannot be said to undergo any proper metamorphosis, like 

 that of Insects and some Crustacea ; since the young one, at its 

 emersion from the egg, possesses the form and most of the gene- 

 ral characters of the parent ; but there is a gradual increase, 

 during the period of growth, not merely in the size of the body, 

 but in the number of segments and legs ; and in one division of 



the class (the lulidae), 

 the young, when it first 

 issues from the egg, is 

 altogether unprovided 

 with legs, these not mak- 

 FIG. 508. TRANSFORMATIONS OK IULUS; ing their appearance until 



after the first moult, 



although they are found beneath the outer skin when it is 

 stripped off. A considerable number of moultings takes place 

 before the animal acquires its adult characters ; and this does 

 not happen, in some species, until after the lapse of two years. 



822. This Class is divided into two Orders, which differ con- 

 siderably from each other in form and development. 



I. CHILOPODA, consisting of the Centipedes and their allies ; 

 in which the body is flattened, and the legs well- developed, 

 constituting the principal instruments of locomotion. They run 

 with facility ; and are carnivorous in their habits. 



II. CHILOGNATHA, consisting of the lulus, or Millepede, 

 and its allies ; in which the body is cylindrical, and the legs less 

 developed. They move slowly; and feed upon decomposing 

 organic matter. 



ORDER I. CHILOPODA. 



823. This Order is the one, in which the greatest resemblance 

 to Insects may be traced. It consists of the Centipede and other 

 carnivorous Myriapods, possessing strong and active limbs, vary- 

 ing in number from fifteen to twenty-one pairs, by the aid of 

 which they can run with considerable rapidity ; and they are 



