62 ELEMENTARY ZOOLOGY. 



Note the three general body regions: hcad f 

 thorax, and abdomen. How are they related 

 to each other in size, shape, and attachment? 

 Is there a "neck," or "waist"? 

 How many segments can you find in each of 

 these regions? Are they equally clear and 

 distinct in the three? Are they equally clearly 

 seen on the back, belly, and sides? What 

 grounds have you for considering that the head 

 is not just one segment and the thorax another? 

 Make a drawing of the side view of a locust, 

 without the legs and wings. Enlarge two 

 or three diameters. 



2. Special Structures. 



a. The carapace and openings. Examine the external covering 

 of the animal. Would you call it "skin"? Why? Is it 

 uniform in thickness and hardness in the various parts of 

 the body? State the facts and give your interpretation of 

 the facts. 



Is each segment covered with one continuous ring or is 

 there an indication of a distinction between a dorsal portion 

 and a ventral portion? Compare the various segments. 

 Openings in the carapace: locate, in relation to the seg- 

 ments, the mouth, anal opening, spiracles (the openings of 

 the breathing apparatus) . How many pairs of spiracles ? 

 Why so numerous? (See text-books.) 



b. Appendages. Begin with thorax. 



How many pairs of legs? What similarities and differences 

 do they show? How are they attached to the body? 

 What is their position in relation to the main axis of the 

 body; that is, do they belong to the anterior half or the 

 posterior half of it ? Examine under a hand lens and draw, 

 showing all the parts. How many segments in each leg? 

 Determine the movement possible to each joint. 

 What is the natural position of the wings when at rest? 

 What is their position in flight ? How many pairs ? Where 

 attached to the body? Are they nearer the dorsal or ven- 

 tral surface ? Nearer the anterior or posterior end ? Do you 



