REACTIONS OF THE MASON WASP TO LIGHT 



355 



The wasps exhibited all of the kinds of behavior mentioned 

 under series I, and, in addition, one was noticed working in 

 the mud, but it did not attempt to construct a nest; and a 

 few of the wasps climbing up through the sunlight were noticed 

 to drop backwards as soon as they reached the shadow. 



The following tables record the positions of the wasps at the 

 times they were observed. 



Experiment 3, June yth, 12 wasps involved. Opaque screen 

 covering the upper portion of the east wall of the cage. 



Wasp resting on or hovering near the 



east side of the cage 



west side of the cage 



roof of the cage 



floor of the cage 



other two sides of the cage 



Total 



Li. 



Sh. 



Experiment 4, June 8th, ign, in the forenoon, 14 to 18 wasps 

 involved. Opaque screen arranged across the middle portion of 

 the east side of the cage so as to leave uncovered two inches above 

 it and three below. 



SERIES III 

 In this series of experiments, the cage containing the wasps 

 was placed in a room of twilight brightness and a pyramid of 

 white light from an electric projecting lantern passed through 

 it at intervals. A water cell was used to filter out the majority 

 of the heat rays. On the lantern side of the cage this gave a 



