106 Trans. Acad. Scr. of St. Louis 
chance, if the direction of the winds could be exactly ascertained 
and urban hindrances eliminated. 
Exp. 41. May 28. Before midnight a heavy fog settled over 
the landscape and the wind ceased; there was not enough breeze 
to flutter a leaf or waver a film of light smoke in the air. No 
moths appeared until the hour of dawn, when 28 came in (27 
young native males and one marked bred moth) in spite of the 
presence of the fog and the lack of wind. 
Exp. 42. May 29. For the first half of the night the moon 
shone brightly ; after midnight it was partly obscured by clouds; 
a fitful wind blew from the east. Although several fine young 
females were on the roof, no cecropias came in until 3:40 a. m., 
when 8 young strangers and one marked one which had been lib- 
erated one mile east three days before, came in. Since they 
were so few, there was ample time for me to watch their arrival; 
most of them came from the west or the southwest. Some of 
them missed their mark and flew too far, over the housetop, but 
returned after a few moments. The dearth of males was con- 
spicuous, but on second thought it was not surprising. During 
the first few experiments there was a dearth of females from 
my cocoons in the laboratory, but at this time the majority of 
those emerging were females, and the shortage was among the 
males. If this condition was duplicated in the wild population, 
it is easy to see how the few wild males would be abundantly 
occupied in their native haunts. May it be, also, that the gentle 
summer breezes did not carry the emanations of the females as 
far as did the strong, direct winds of a few days before, and 
hence reached only those near by? 
Exp. 43. May 30. Wind, faint breeze from east; station 44 
mile east. The following 30 cecropias were liberated in Tower 
Grove Park at 9 p. m.: 7 natives that had come in at dawn 
of that day, 12 from the dawn before, 5 from two mornings 
before, four bred males aged one and two days, and 2 natives 
which had come in from a previous test flight. None of the bred 
cecropias returned, but at 11 p. m. one wild one which had come 
in the day before arrived, and at dawn three more wild ones 
returned, and the following dawn three more. This shows et 
least that four out of 30 (considering only those which came 0 
the first night) could find the females against the odds of a dis- 
