l8 INSECT LIFE. 



be separated from the remainder of the thorax. This 

 is the first of the segments of the thorax. 



5. Separate the first segment of the thorax from 

 the remainder of this region. Observe that the belly 

 or ventral side is small, while the upper or dorsal side 

 is large, being composed of the large sunbonnet- 

 shaped piece which is just back of the head. 



6. The first segment of the thorax is called the 

 prothorax {pro-tho'rax). 



7. Make a drawing of a side view of the prothorax 

 representing the left side. 



8. The portion of the thorax remaining consists 

 of two segments closely grown together. These are 

 the second and third thoracic segments. The second 

 thoracic segment bears the second pair of legs and the 

 first pair of wings ; the third thoracic segment bears 

 the third pair of legs and the second pair of wnngs. 

 Study the specimen and try to make out the limits 

 of these segments. 



9. The second or middle thoracic segment is called 

 the mesothorax {mes-o-tho'rax). The third or last tho- 

 racic segment is called the metathorax {inet-a4ho' rax\ 



ID. Remove the wings and make a drawing of 

 the left side of these two segments. 



II. Observe that the greater part of each side of 

 these two segments consists of four large, oblique 

 pieces. The first two of these pieces belong to the 

 mesothorax, the last two to the metathorax. 



Review, — The body of an insect consists of a series 

 of segments ; of these the first three behind the head 

 form the thorax. The three segments of the thorax 

 are called the prothorax^ the mesothorax, and the meta- 

 thorax respectively. 



