CHAPTER XV. 



THE MYRIAPODA. 



The Myriapods, fa.milia.rly known as the Hundred Legs, or Centi- 

 pedes, were formerly classified with the true insects, but of late 

 years they have been separated from them, and arranged in a class 

 by themselves. A very superficial examination of the charac- 

 teristics of the Myriapods will be sufficient to explain the necessity 

 for this separation, and it is rendered absolute after the study of 

 the early development and growth of these many-legged creatures. 

 The aspect of the perfect Myriapod does not give the least insight 

 into the interesting series of developments which produced it ; and 

 yet their early structures are those which ally them to the larvae 

 of the insect classes already described. 



Common observation decides at once that the Myriapods have 

 a great number of legs all very much alike, and that they have a 

 head ; but the division of the body into the thorax and abdomen, 

 as in true insects, is not apparent, for the head is followed by a 

 long series of segments or rings, each giving attachment to one 

 or two pairs of legs. The distinction between the thorax and 

 abdomen, as hitherto applied, is therefore impossible, for instead 

 of the locomotive organs being restricted to the segments of the 

 thorax, and being absent in the abdomen, all the segments or 

 rings of the Myriapoda are supplied with them. 



The mouth of the Myriapod has much in common with that 

 of the insect, and is composed of a labrum, two mandibles, two 

 jaws, and a lower lip, or second pair of jaws ; but the first two or 

 three pairs of legs enter into the category of mouth organs also, 



