64 INTRODUCTION TO ZOOLOGY. 



3. How many antennie? How many segments in 

 each ? 



4. Find the mandibles. Are the things you take 

 to be mandibles, true mandibles? Are they on the 

 head? Are they jointed? 



5. You may call this pair of mandible-like appen- 

 dages the maxillipeds, or foot jaws. 



6. Find and identify the true mouth parts. Draw 

 one of each pair. 



7. How many body segments behind the head? 

 What does each segment bear? How do the legs 

 on the first segment differ from those on the other 

 segments ? How do the legs on the last segment dif- 

 fer from the other legs? 



8. Do you find spiracles? On what segments? 

 How many? 



9. Do you see any way to explain why an insect's 

 jaws move sideways? 



THE THOUSAND LEGS. 



{Polydesmus. ) 



1. Are there any body divisions? Identify the 

 head clearly. 



2. Find and draw one of each pair of mouth parts 

 and antennae. 



3. Find the eyes. Are they simple or compound? 

 How arranged? Compare with the eyes of a cater- 

 pillar. 



4. How many segments in the body? How many 

 pairs of legs? Hold this fact until we study the 

 earthworm. 



5. How many segments on each leg? Are all the 

 legs alike? Draw one. 



6. Do you find spiracles? How many? 



7. In what respects does a caterpillar resemble a 

 thousand legs? 



