dead.  The balloon appears to be made while the insect is flying in the air.  Those flying highest had the smallest balloons.  The bubbles are probably produced by some modification of the anal organs.  It is possible that the captured fly serves as a nucleus to begin the balloon on.  One case of a captured fly but no balloon was observed.  After commencing, it is probable that the rest of the structure is made by revolving the completed part between the hind legs and adding more bubbles somewhat spirally.  The posterior end of the balloon is left more or less open.  The purpose of this structure is to attract the female.  When numerous males were flying up and down the road, it happened several times that a female was seen to approach them from some choke-cherry blossoms near by.  The males immediately gathered in her path, and she with little hesitation selected for a mate the one with the largest balloon, taking a position upon his back.  After copulation had begun, the pair would settle down toward the ground, select a quiet spot, and the female would alight by placing her front legs across a horizontal grass blade, her head resting against the blade so as to brace the body in position.  Here she would continue to hold the male beneath her for a little time, until the process was finished.  The male, meanwhile, would be rolling the balloon about in a variety of positions, juggling with it, one might almost say.  After the male and female parted company, the male immediately dropped the balloon upon the ground, and it was greedily seized by ants.  No illustration could properly show the beauty of the balloon.” (Aldrich and Turley, “A Balloon-making Fly,” American Naturalist, October, 1899.)

“In many species of moths the males ‘assemble’ around the freshly emerged female, but no special advantage appears to attend on early arrival.  The female sits apparently motionless, while the little crowd of suitors buzz around her for several minutes.  Suddenly, and, as far as one can see, without any sign from the female, one of the males pairs with her and all the others immediately disappear.  In these cases the males do not fight or struggle in any way, and as one watches the ceremony the wonder arises as to how the moment is determined, and why the pairing did not take place before.  Proximity does not decide the point, for long beforehand the males often alight close to the female and brush against her with fluttering wings.  I have watched the process exactly as I have described it in a common Northern Noctua, the antler moth (Charaeax graminis), and I have seen the same thing among beetles.” (E.B.  Poulton, The Colors of Animals, 1890, p. 391.) This author mentions that among some butterflies the females take the active part.  The example here quoted of courtship among moths illustrates how phenomena which are with difficulty explicable by the theory of sexual selection in its original form become at once intelligible when we realize the