8 



Fig - . 7. Myriapod. Millipede. 

 Reduced. {Original.) 



^r^^m^m^ 



Fig. 



8. A primitive insect. 

 The silver -fish. 



Adult. Enlarged. {From U. S. 



Dept. A^ric.) 

 pairs of wings is wanting, as in the silver-fish (Fig. 8). 



The Millipedes (Fig. 7) are 

 mostly scavengers, feeding on 

 decaying vegetable matter, 

 though sometimes they attack 

 growing plants. They are not 

 often pests, however. 



Class IV is the Hexapoda, or 

 true insects. The name Hexa- 

 poda means having six legs, 

 and this expresses one of the 

 most distinguishing characters 

 of the insect. In addition to be- 

 ing arthropods having six legs, 

 insects are to be distinguished 

 from others of the group by the 

 following; features. The insect 

 body is readily separable into 

 three definite regions head, 

 thorax and abdomen, and the 

 adult is usually winged. The 

 normal number of wings is two 

 pairs, but it sometimes hap- 

 pens that one, or even both, 



