BEHAVIOR OF A PARASITIC BEE 381 



several climbed up the light place on the left side to the shadow 

 at the border of the top. Several of those that flew up to the 

 top of the cage clung thereto and walked about, sternum up- 

 wards, in the sunshine. 



Experiment 9. — At 11.45 a. m., an opaque screen covering 

 the upper six inches of the netting of the window-side of the cage 

 was substituted for the opaque screen used in Experiment 8. This 

 caused the lower portion of the window-side of the cage to be strongly 

 illuminated, while the upper six inches was in shadoiv. Other- 

 wise the arrangement of light was as in Experiment 8. 



The day was warm, the temperature in the shade was 88 

 degrees F., and the bees were restless. They would not remain 

 long in any one position. In this experiment accurate account 

 was kept of the number of times bees alighted, in ten minutes, 

 on any netting of the cage. If the same bee alighted on any 

 of the walls more than once it was counted each time. During 

 that period bees alighted on the light patch fifteen times. 

 Thirteen times a bee climbed up through the sunlight on the 

 window-side of the cage until it reached to edge of the shadow 

 and then dropped backwards. One bee climbed up through 

 the sunlight on the window-side of the cage and continued 

 on into the shadow until it reached the top of the cage, and 

 rested there several minutes. Another bee did practically the 

 same thing, only it stopped before it reached the top. 



SERIES II (MAY 3, 1911) 



Experiment 10. — .4/ 2 p. ni., the cage was placed in front 

 of an electric projecting lantern and a beam of light allowed to 

 pass through. On the lantern-side of the cage the beam of light 

 was eight inches wide by six inches high; on the side remote from 

 the lantern the beam was nine by seven inches. On the lantern- 

 side the bottom of the beam was four inches above the bottom of 

 the wire netting, on the opposite side of the cage the bottom of the 

 beam of light was two and a half inches above the bottom of the 

 netting. The other portions of the cage were illuminated by diffuse 

 daylight, admitted by windows on one side of the room. 



At the beginning of this experiment a few bees were resting 

 on the netting on the window-side of the cage, the remainder 

 were out of sight. As soon as the light was turned on, a male 



