Branch Arthropoda 71 



THE BUTTERFLY 



Before mutilating the specimen, study carefully its gen- 

 eral structure. Notice the relative sizes of the wings and 

 body, the markings on the wings, and the hairy covering 

 of the body. 

 I. — Note the relatively large size of the compound eyes ; 



examine the outer surface of one with a lens to see its 



honeycomb appearance. 

 II. — Are there any ocelli ? If so, where are they situated ? 



III. — Examine the antennae. What is the general shape .' 

 About how many segments are there in each ? Which 

 segments are the longest ? How does the basal seg- 

 ment differ from the others .■' 



IV. — Notice the long coiled sucking organ — the proboscis 

 — at the mouth. Is it composed of one or two pieces .-' 

 Notice the two jointed hairy organs beside the probos- 

 cis : these are the labial palpi. The proboscis is formed 

 of the modified maxillae. « 



V. — Notice the small thorax in close connection with the 



head. Compare the connection with that found in the 

 dragon-fly. 



VI. — Observe the large mesothorax bearing the front pair 

 of wings. Find the suture between it and the meta- 

 thorax which bears the posterior wings. 



VII. — Notice the fragility of the legs. Give a reason for 

 their small size as compared with those of the grass- 

 hopper. 



VIII. — Are the front legs as large as the others ? When 

 you have a chance to see a large butterfly walking, see 

 how many feet it uses. 



IX. — Place a piece of the wing under the low power of 

 the microscope. Observe the shingle-like arrangement 



