172 Trans. Acad. Sci. of St. Louis 
so Many wings created a loud humming noise. Many of the 
males kept their antenne in excited motion much of the time, 
and in one case an individual crowded near to the glass and 
pulsated his abdomen in unison with his wings. 
Seven minutes of this activity gave all the evidence that we 
needed, so I darkened the box again; almost immediately the 
hum subsided, and quiet reigned. This condition continued for 
thirteen minutes. Then the cover was lifted at the opposite 
end and the strong light, the 75-watt lamp with aluminum re- 
flector, was placed against the outside of the glass. It was three 
minutes before any of the 78 moths showed signs of response, 
and then only two slowly vibrated their wings. After seven 
minutes, eight were waving the wings; three of these came to 
the light. After being subjected to this dazzling light for ten 
minutes, five were flying against the glass part of the time, 
and part of the time they flew back into the corners away from 
the light. One more male occasionally moved a wing. Thus 
of the 78 moths, only 6 made response to intense light, and the 
majority of these responses seemed half-hearted or confused, 
and in a few minutes, even while the light was upon them, these 
settled down to quietude. After a quarter of an hour it was 
evident that the show was all over, so the cage was again dark- 
ened. An hour later it was opened again at one end to see if a 
larger number would now respond to a mild light (that of an 
east room at 5:00 p. m.). Immediately when the curtain was 
lifted, three moths broke into fluttering, and in three minutes 
three more were beating against the glass at the light end. After 
the cover had been up ten minutes, twenty moths were doing 
various antics, as before. It was growing darker in the room 
now, and rather than turn on the electric light (since this was 
to be an experiment with subdued natural light), I admitted 
more light to the box by lifting the curtain on one side in addi- 
tion to the one end that was already exposed. In five minutes 
more than half of the inmates of the cage had joined in the 
excitement, but after eighteen minutes many of those which 
were first active began to slow down and a few became quiet. 
Here again we find much greater response to diffused light of 
low intensity than to intense light. To the moths, et 
the opposite extremes in the intensity of light mean eee 
ingly opposite behavior; brilliant sunlight or its counterpart 
