296 Trans. Acad. Sci. of St. Louis. 



Object. — To see whether the female will show prefer- 

 ence for a normal 5-day-old male or a younger anten- 

 naless one. 



Results. — June 7, 9:00 A. M. Mating has not yet occurred. It ap- 

 pears that the antennaless male is incapable of mating. Male 163, a 

 normal male of unknov/n age and history, is now introduced. June 8. 

 The female found in copulo with this stray male. 



Experiment 36. — Jime 6, 9 :00 P. M. 



(^136. Age 8 days 4:50 hours. Mated. 

 c^l59. Age day 6:30 hours. 

 9 155. Age 1 day 4:00 hours. 



Object. — To see whether a young female will be won 

 by a young, unmated male, or an old, mated one. 



Results. — June 7, 7:00 A. M. The female found in copulo with the 

 younger male. 



Experiment 37. — June 6, 9 :30 P. M. 



4 



(^160. Age day 7:00 hours. 

 9 153. Age 1 day 5:40 hours. 

 9 158. Age day 7:30 hours. Antennae removed. 



Object. — To see if a young male will prefer a normal 

 female aged I14 days, or one of 7 hours, but with the 

 antennae removed. 



Results. — June 9, 9:00 A. M. After being together for almost 3 

 days, mating has not yet taken place. In order to ascertain definitely 

 whether an antennaless female can mate, male 160 and female 153 are 

 now removed, and a new male, 173, introduced. — June 10, A. M. 

 This pair found in copulo. 



This proves that an antennaless female is quite cap- 

 able of mating. 



Experiment 38. — June 6, 10 :50 P. M. 



c^l42. Age 4 days 7:20 hours. 



(^147. Age 2 days 5:40 hours. Antennae removed. 



9 150. Age 1 day 9:20 hours. 



Object. — ^To see if mating will take place with the nor- 

 mal male of 4 days, or the antennaless one 2 days old. 



