THOUSAND LEGS. 23 



1. How many segments has the body ? 



2. How many appendages has each segment ? 



3. Make a drawing of the thousand legs. 



4. What are the chief differences between this animal 

 and insects ? 



Another common form of thousand legs (Lithobius 

 americanus) is that called (wrongly) "centipede," or 

 (also wrongly) ''ea rwig." It is, when full-grown, about 

 an inch long, with a broad, flat head, a brown, shiny back, 

 the segments being mostly of about the same size, with 

 one pair of jointed appendages to each segment. The 

 antennae are many jointed. It is found under boards, and 

 about rubbish, and manure heaps, where it feeds on insects 

 and earthworms. 



1. Examine the jaws and mouth parts carefully ; how 

 many pairs of jaws are there ? 



2. With a lens examine the legs. How many are there ? 



3. What kind of eyes are there ? How many, and how 

 placed ? 



4. Arrange the legs so they can be distinctly seen, and 

 make a drawing as seen from above. 



5. Make an enlarged drawing of the mouth parts as seen 

 from below. 



6. What are the differences between this form and the 

 thousand legs mentioned above ? 



7. In what are the two alike? Both belong to the 

 class Myriapoda. Carefully compare them with the 

 insects, and make a list of points common to insects 

 and myriapods ; also a list of the characters which 

 insects have and the myriapods do not have ; and a 

 list of points peculiar to myriapods. 



