436 N. E. MCINDOO. 



TELEPHORID^. 



The Olfactory Sense of Chaulcognathus pennsylvanica. 



Many fireflies {Chaulcognathus pennsylvanica) were caught on 

 goldenrod {Solidago). They were put into a cage 20 inches long, 

 16 inches tall and 12 inches wide. The sides and top of the cage 

 were cheesecloth while the ends and bottom were wood. The 

 cage was kept in the light near a window and a fresh supply of 

 goldenrod was constantly kept in the cage. On the goldenrod 

 in the cage, these insects appeared quite "at home." Twenty- 

 five of them were tested with the odors from the three essential 

 oils. When tested most of them moved away quickly; a few 

 vibrated antennae; a few vibrated legs, and a few arose slowly. 

 They were extremely restless at all times. In the cage they 

 copulated as freely as they do out-of-doors. 



Their reaction times are as follows: Oil of peppermint, 2 to 12 

 seconds, average 2.6 seconds; oil of thyme, 2 to 10 seconds, 

 average 3 seconds; oil of wintergreen, 2 to 10 seconds, average 3 

 seconds. The general average reaction time to all three odors is 

 2.8 seconds. They lived from 3 to 7 days with 3.2 days as an 

 average. 



(a) Effects ivith Antennce Pulled Off. 



The antennae of 27 Chaulcognathus pennsylvanica were pulled 

 off at their bases. A day later only three were alive. When 

 tested these three responded as promptly as unmutilated ones. 

 The general average reaction time to the odors from the three 

 essential oils is 2.8 seconds. Counting all 27 beetles, they lived 

 from I to 5 days with 1.3 days as an average. 



LUCANIDyE. 



The Olfactory Sense of Passalus cornutus. 



Four stag beetles (Passalus cornutus) were removed from rotten 

 stumps. While being tested with odors they were compara- 

 tively quiet and responded promptly. Their most common 

 response was to draw in the antennae and to move away slowly. 

 The general average reaction time to all six odors is 3.2 seconds. 

 The antennae were pulled off at their bases. A small drop of 



