REACTIONS OF THE MASON WASP TO LIGHT 357 



Experiment 8. At 1:4s p. m. the cobalt glass was placed before 

 the lens. 



By 2 o'clock all of the wasps were quietly resting upon some 

 portion of the cage. 



Experiment g. At 2:03 p. m. the cobalt glass was removed, 

 permitting the white light to pass through the cage. 



At 2 :o4 p. m. a wasp began to fly and in less than two minutes 

 four were on the wing. 



Experiment 10. At 2:12 the piece of cobalt glass was placed in 

 front of the lens. 



Almost immediately the wasps became quiet. A little later 

 one flew a short distance and then settled down. At 2 115 p. m. 

 two were walking about, but none was on the wing. 



Experiment 11. At 11:25 a - m -, after the cage had been in 

 twilight darkness for several hours and the wasps were resting 

 upon parts of the cage, a pyramid of orange light was passed through 

 the cage. 



Immediately the wasps began flying at random about the 

 cage and hovering before the sides; but, at 11:29 a. m., all had 

 become quiet again. 



Experiment 12. At 11:30 a. m. the light was turned out. 



Experiment 12. At 11:46 a. m., a pyramid of orange light 

 was passed through the cage. 



At first there was practically no reaction. Seven wasps were 

 resting on the sides of the cage with their heads directed upwards, 

 one with its head directed downwards and seven with their 

 heads directed sidewise. Three wasps were resting on the floor 

 of the cage, and one wasp was cleaning its head, wings and 

 abdomen. At n 150 a. m. one began to fly and one was making 

 a humming noise. In less than a minute after that several 

 were flying at random about the cage, and others were crawling 

 up the sides of it. At 11 155 a. m. all were quiet again, but at 

 11:56 several were on the wing. 



Experiment 13. The light was turned off at 11:58 a. m. 



Immediately all became quiet. 



Experiment 14. At 12:00 m. a pyramid of ruby light was 

 passed through the cage. 



Immediately the wasps became active. Some walked about 

 in an excited manner, others made random flights about the 

 cage and yet others hovered before the sides. On alighting from 



