PART I. 
INTRODUCTION. 
Night ever draws a veil of mystery about the things which 
belong to her domain. Although childhood’s fear of the dark 
may have been explained away, yet the feeling lingers that in 
the realm of Luna we may expect something of the weird. Per- 
haps this, but more probably our love of undisturbed slumber, 
has led to an excess of fancies but a deplorable dearth of re- 
liable information concerning the activities of these interesting 
denizens of our woods, the giant Saturniid moths. 
Several years ago a well-known entomologist fascinated me 
with the story of how he had observed the males of the Saturniid 
moths ‘‘fly great distances up hill against the wind to reach the 
females.”? ‘‘How far,’’ thought I, ‘‘can they actually travel, 
and what directs them there?’’ The question caught my fancy, 
and during the intervening years I have often thought of this 
“‘romantie’’ behavior. Often I was tantalized by seeing in the 
literature some Meager references to this phenomenon, but 
While some authors suggested theories as to the guiding stimulus, 
hone offered any experimental evidence as proof of any theory. 
Finally, bent upon an attempt to solve these problems of the sex 
life of the giant Saturniids, or more precisely stated, a study of 
how far the males can travel to reach the females, and what 
mechanical or psychical factors influence their reactions, I ob- 
tained a large number of cocoons of four species of these moths, 
to add to our native population here, and made detailed observ- 
ations throughout the season. 
The work was all done from the third story window and on 
the second story roof of the rear of the house, which could be 
reached from said third story window, of a city dwelling (fig. 2 
shows a portion of this roof and view toward the west). At the 
Windows and on the roof, from time to time, wire cages rsicagaal 
mg the female moths were placed. Then, taking a position of 
watchfulness, net in hand, I kept vigil through a greater part 
of the night, every night, from May 7 to June 27, a period of 
fifty-two days, which is the duration of the natural season for 
these species. Hach moth was numbered, in oil paint, on the 
Wings, and individual records kept of the age and activities of 
