112 



ANIMAL FORMS 



species especially causes painful but not fatal wounds in 

 man. 



On the other hand, the millipeds (Fig. 68) or thousand- 

 legs are cylindrical, slow-going animals, feeding on vegetable 



PIG. 67. Centiped. 

 One-half natural size. 



FIG. 68. Thousand-legs or milliped (Julus). 

 Natural size. 



substances without causing any particular damage, except 

 in the case of certain species, which work injury to crops. 

 When disturbed they make little effort to escape, but roll 

 into a coil and emit an offensive-smelling fluid, which ren- 

 ders them unpalatable to their enemies. 



All present a great resemblance to the segmented worms, 

 as their popular names often testify; but, on the other 

 hand, many points in their organization indicate a closer 

 relationship to the insects. As in the latter, the head is 

 distinct, and bears a pair of antennas, the eyes, and two or 

 three pairs of mouth-parts. The trunk is more worm-like, 

 and consists of a number of similar segments, each bearing 



