300 Trans. Acad. Sci. of St. Louis. 



Experiment 49. — June 10, 7 :00 A. M. 



(^ 174. Age days 16 : 00 hours. One antenna removed. 

 $ 156. Age 4 days 13:50 hours. 



Object. — To find if, when both insects are of favorable 

 age, a male with one antenna can mate. 



Results. — ^June 13. The pair have been together until the present 

 time without mating, which goes to show that this male with only one 

 antenna cannot find the female. 



Experiment 50. — June 10, 8 :00 A. M. 



c? 175. Age day 17 : 00 hours. Left antenna removed. 

 $ 164. Age 2 days 16:30 hours. 



Object. — To find if a male with one antenna can mate. 



Results. — ^June 13. After 3 days, mating has not occurred. 



It seems that here again the condition of the antennae 

 of the male, and not the age of the insects, must have 

 been the controlling factor. 



Experiment 51. — June 10, 8 :00 A. M. 



$ 176. Age 1 day. 



c? 177. Age day 17 : 00 hours. Right antenna removed. 



Object. — Same as Experiment 50, but testing right in- 

 stead of left antenna. 



Results. — ^June 13. After 3 days mating has not taken place. 



Experiment 52.— June 10, 10:00 P. M. 



c^l79. Age 1 day 7:00 hours. Wings slightly torn and left 



antenna crumpled. 

 $ 153. Age 5 days 6:10 hours. 



Object. — To see if the deformed antenna of the male 

 will hinder mating. 



Results. — June 12, 8:00 A. M. Mating has not taken place after 

 two days. 



This female proved her readiness to mate in a later 

 experiment; hence the fault must lie in the defective 

 antenna of the male. 



