CHART DR ev 
THE MYRIAPODA. 
THE J/yriapods, familiarly 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 W7yrizapods 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 J/yriapod 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 larve 
of the insect classes already described. 
Common observation decides at once that the J/yrzapods 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 A/yriapoda are supplied with them. 
The mouth of the MWyriapod 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, 
