292 Trans. Acad. Sci. of St. Louis. 



but the only available one, is placed with the two females. — Later. All 

 the insects die without mating. 



Experiment 22.— May 9, 10:00 P. M. 



c? 84. Age day 10:10 hours. 



$ 101. Age day 4:50 hours. Wings very ill appearing, 



dried before being inflated. 

 $ 75. Age 7 days 7:20 hours. Beautifully colored. 



Object. — To ascertain if a male will mate with a 5-liour- 

 old female whose wings are in a dilapidated condition, in 

 preference to a physically normal one seven days of age. 



Results.— May 11, 8:00 A. M. Not until this time is the male 

 found in copulo with female 75. 



This is an instance of a normal, old female being pre- 

 ferred to one yornig and dilapidated. 



Experiment 23.— May 9, 10 :00 P. M. 



(^16. Age 11 days 9:10 hours. Wings badly damaged. 

 c^34. Age 10 days 8:30 hours. 

 $ 88. Age day 9:50 hours. 



Object. — ^Will the female mate with the dilapidated 

 male eleven days old, or with a perfect male a day 

 younger? 



Results. — May 10, 8:00 A. M. The female found in copulo with 

 male 16 in spite of the fact that he is the older and in a very ragged 

 condition. 



Experiment 24.~May 9, 10 :00 P. M. 



(^ 9. Age 12 days 6:00 hours. Wings badly tattered. 

 c? 59. Age 8 days 6 : 20 hours. Wings removed. 

 9 91. Age day 9:14 hours. 



Object. — Will the female mate with the extremely old, 

 badly worn male, or one which is 4 days younger, but 

 wingless f 



Results. — ^May 12, 8:00 A. M. No mating having occurred up to 

 this time, the two males are removed and male 39 is placed in their 

 stead. — May 15. Male 39 is found dead; mating has not yet taken 

 place.' 



