42 



GENERAL ZOOLOGY 



projecting backward on the ventral surface of the prothorax, 

 and a corresponding cavity on the ventral surface of the 

 mesothorax. When the beetle falls upon its back, as often 

 happens from its habit of dropping to the ground as though 

 dead, the legs are so short that they are unable to help 

 much in regaining its position ; then the spine on the pro- 

 thorax is driven into the cavity of the mesothorax with 

 force sufficient to cause the base of the wing-covers to strike 

 against the surface and throw the beetle into the air. If it 

 lands wrong side up, the act is repeated until success crowns 

 its efforts. The larvae are called wireworms, and live in 

 decaying wood or attack the roots of vegetables. 



Our largest species is called the eyed click-beetle (A'laus 

 ocula'tus, Fig. 25), on account of the oval, eye-like spots on 



the back of the prothorax. These 

 spots have been thought to be of 

 the nature of terrifying organs. 

 Professor Needham of Lake Forest 

 University says: " If there be one 

 thing more than another of which 

 animals are suspicious, it is a 

 strange-looking eye. Nature has 

 taken advantage of this fact in 

 protecting some of the most 

 innocent little creatures by devel- 

 oping upon them spots that look 

 like sinister eyes." Several South 

 American and West Indian species 

 of click-beetles have the power 

 of emitting light from spots on 

 the side of the prothorax and 

 abdomen, and are used by the 

 natives as ornaments, being sewed in lace and worn on the 

 head. The light is the most brilliant and continuous of any 



FIG. 25. Eyed Click-Beetle. 

 Slightly enlarged 



