38 



ELEMENTARY STUDIES IN INSECT LIFE 



stantly used. By the sense of smell, insects are enabled 

 to discover food, to recognize their friends, avoid their 

 enemies, and to seek their mates. 



These various uses have been confirmed repeatedly by 

 experiments. ( 'ertain carrion-eating beetles inclosed in 

 a large box invariably sought out a small bit of decay- 

 ing flesh within a bottle located in one corner. When 

 the antenna 1 were covered with wax, so that the olfactory 

 nerves were no longer sensible, the beetles no longer 

 found the meat. Flies were attracted into a room by 

 a piece of decaying meat. It seemed impossible to 

 drive them away from the meat. These same flies paid 

 no attention to the meat after they had been caught and 

 their antennse rendered insensible. The actions of the 

 insects in other respects seemed normal, so that their 

 indifference toward the meats could not be charged to 

 any discomfiture from the temporarily insensible an- 

 tenmr. Closely constructed boxes in which were in- 

 closed certain species of female moths have attracted 

 the males of this same species. The males of such 



FIG. 24. Heads of (a) male and (b) female Cecropia moths. Photographed on 

 same scale, illustrating the greater development of antennce in male moth. X 2. 



