The Nuptial Flight 145 
other Saturniid species that does so.* Here then is excellent 
material for experimental studies in rhythmic periodicity. 
The tests have proven that it is possible for the bred as well 
as the wild prometheas to fly to their mates from a distance of 
one mile, and in surprisingly short time too—ten to twelve 
minutes. When part of the cages were placed on the ground, 
they came to those on the roof just as readily as they did to 
those on the ground. I have never seen these moths come in 
during the rain, but I have seen them come in between showers. 
*Fabre gives a few instances. 
