278 Trans. Acad. Sci. of St. Louis. 



tinued for ten minutes, and now all have settled down quietly for the 

 evening. — April 28, 11:00 P. M. Death of female. Mating has not 

 taken place although the insects have been together for over three days. 



Thus, eager as this male and the old fertilized female 

 were to mate, copulation did not occur. 8o long as 

 mating was not sincerely sought by the female, which 

 had by this time deposited many fertile eggs, why this 

 coquettish display and eagerness to arouse the male? 

 It may be that she instinctively behaved thus when 

 brought into the presence of unmated males. We must 

 not overlook the fact that the old age of the female may 

 have prevented mating, but old age surely did not pre- 

 vent the desire. 



When we recall the prime age of the mated male, we 

 are surprised at his unswerving indiJfference throughout 

 the experiment. We cannot argue that the previous mat- 

 ing caused the female to lose certain attractiveness (odor, 

 etc.), for we saw her perfectly successful in exciting the 

 unmated male. Why the activity on the part of an old 

 mated female and not so on the part of a young mated 

 male? 



Experiment 4. — April 25, 4 :00 P. M. 



(^ 5. Age 3 days 3 : 30 hours. 



$ 2. Age 10 days 2:30 hours. Fertilized and eggs deposited, 



Object. — To find if a female which has been fertilized 

 and has oviposited will again mate if the male be still 

 unmated. 



Behavior. — 4:00. The female is unmoved when the male is intro- 

 duced; male at once becomes active. As his wooing becomes too 

 ardent, the female demurely moves to the far end of the cage and 

 there remains indifferent. The male takes his position on the floor 

 of the cage some six inches from her, raising the fore part of his, 

 body high up, and resting on the two hind legs and the tip of the 

 abdomen. The four front legs are folded up close to the thorax — 

 "clasped to his throbbing heart." la this position the wings are rap- 

 idly beaten against the floor, creating an audible hum. This balancing 

 and "music" has continued for exactly three minutes without causing 



