176 Trans. Acad. Sci. of St. Louis 
with sensitiveness and react to certain conditions of light and 
odor; moreover, some display much emotion, and some make 
strenuous advances in courtship. 
Summary 
We find that the phenomenon of the nocturnal periodicity of 
the males is not so deeply ingrained in the psychology of the 
cecropia moth that it cannot be changed with changes in the 
condition of light and darkness. It seems they respond to re- 
recurring periods of light of certain intensity, whether these pe- 
riods occur once or half a dozen times in the twenty-four hours. 
If the measured periods were deeply ingrained in their be- 
ings, whether physiological or psychological, they would react 
only when the cycle (hour) recurred, regardless of whether 
they were in a darkened box or in the brightest sunshine. As 
a matter of fact, they do not become active under either of these 
two extremes, but the optimum activity is reached under con- 
ditions of diffused daylight, which to them is probably similar 
to the light of very early dawn. If this condition is created at 
almost any time, a good percentage of responses may be 
expected. 
In regard to the females, the experiments show that they re- 
spond mildly to proper light conditions, and more actively when 
the odor of males is added. The female is not wholly devoid of 
sex perception; she has the ability to perceive his odor and has 
the power to reach him when he is in the path of light. More- 
over, she displays enough emotion to proclaim to the world that 
she, too, is a party in the courtship. 
The results of this series of experiments on light reactions 
show for the males at least positive response to the stimulus of 
diffused daylight, negative response to direct electric light of 
high intensity, and a response half-way between the two for an 
electric light of medium intensity.* This, of course, is what one 
would expect in a moth whose activities are influenced by day- 
ennedy (Ann. Ent. Soc. Amer. 20: 87, 1927) finds that aren) 
Pon — are so sensitive to light that they are eg eig e 
talepsy in strong light by overstimulation. He 
lf mile away, ignorin. 
stone flies siranted to a 75-watt light ha oS eae 
candle power gas mantle lantern on a creek bank. He also 
hanging on = Bolo motionless, with an electric light on. = ssn 
went out and a single candle was lighted; some two d en tha 
been hanging sattonGaas then became fully active. 
