ARTHROPODS. CLASS CRUSTACEA 113 



one or two pairs of jointed legs. In their internal organ- 

 ization the character of the various systems closely resem- 

 bles that of the insects, and will be more conveniently 

 described in that connection. 



Among the myriapods the females are usually larger 

 than the males. Some of the centipeds deposit a little 

 mass of eggs in cavities in the earth and then abandon 

 them, while others wrap their bodies about them and pro- 

 tect them until the young are hatched. The millipeds lay 

 in the same situations, but usually plaster each egg over 

 with a protective layer of mud. After several weeks the 

 young appear, often like their parents in miniature, but in 

 other species quite unlike, and requiring several molts to 

 complete the resemblance. 



