Insecta. 23 



window pane? Examine the feet? In what order does the fly 

 move its feet in walking? For the study of this point, take a 

 fly that is sluggish from cold, or from partial drowning. Do flies, 

 on the whole, injure man, or benefit him? Flies belong to the 

 order Diptera, or two-winged insects. What other insects have 

 but two wings ? 



Topics for Reports. The Mosquito and Disease. House Flies. 

 Horseflies. Botflies. 



THE BEETLE. 



1. What are the characters that appear peculiar at first sight? 



2. Note the position and shape of the eyes. 



3. The antennae, their attachment, parts, and mode of extension. 



4. A small upper lip, the labrum. 



5. A pair of strong jaws, the mandibles, often very large, and 

 projecting forward as pinchers, or " horns." How do they move? 



6. Back of these are two small jaws, the maxillae, bearing a 

 pair of jointed appendages, the maxillary palps. 



7. Back of (posterior to) the maxillary palps is another pair of 

 similar appendages, the labial palps. 



8. The part of the body back of the head is the prothorax. 

 Why not call it the thorax ? 



9. Pry up the hard outer wings. How do they meet each 

 other? Each outer wing is called a wing cover, or elytrum. In 

 what direction does the beetle move the elytra in raising them ? 

 How are they held during flight? Do they rise vertically? 



10. How are the inner wings folded? Compare the inner and 

 outer wings in length and size. Cut a piece of paper of the same 

 shape as the inner wing, and fold it as the inner wing is folded. 

 How does the beetle perform the act of folding the inner wings? 

 Capture live beetles and watch this process. 



11. Make a drawing of the back, with the wings closed; an- 

 other drawing, with the wings fully expanded, as in flight. 



12. Count the segments of the legs. Examine each segment 

 closely. Seize the foot of one of the hind legs with the forceps, 



