1 8 Descriptive Zoology. 



adaptation to new surroundings and a gradual advance- 

 ment to changed conditions of life. 



ORDER HEMIPTERA. 



The Giant Water Bug. This is the largest of the bugs, 

 being two and one half inches long. It lives in the water 

 of our lakes and rivers, but was not very generally known 

 until electric lights became common. The light attracts 

 them, and they are frequently found where they have fallen 

 under the lamps. Consequently many people call them 



FIG. 9. GIANT WATER BUG. 



From Hyatt's Insecta. 



the " Electric Light Bugs." They are more abundant in 

 river towns that are lighted by electricity, and a good way to 

 collect them is to look for them under the lamps late in the 

 evening. By preserving them in alcohol enough may be ac- 

 cumulated to supply a class. They serve admirably to show 

 the chief characteristics of bugs, and are large enough to dis- 

 sect if the student wishes to learn the internal structure. 



The head is relatively small and the neck is not con- 

 spicuous. The prothorax is large and broad. The outer 

 wings are narrow in front, being separated by a triangular 

 elevation of the mesothorax, called the scutellum. Then 



