As faille XV Indicates, very few flowers were tripped 

 during the period from August 22 to August 26, either in- 

 side or outside of the netting tents; whereas, in the few 

 dajT-s preceding August 22, verj^ nearly all flowers in 

 these two fields hecame tripped after being; open for a 

 short time. Prior to August 22, the atmosphere was clear 

 and fairly warm. By August 22, it became much colder; a 

 hard frost occurred on the night of August 24th. During 

 the three or four days following August 22, it was ob- 

 served that when alfalfa flowers were artificially tripped 

 the pistil and stamens did not snap up against the stand- 

 ard as promptly and vigorously as in the case of those 

 flowers that were artificially tripped during the days 

 preceding August 22. 



The only natural external agencies that could have 

 caused the flowers to trip and produce pods so abundantly 

 just prior to August 22 would have been honejr -gathering 

 insects, or possibly the action of wind. 



The latest date on which there was any appreciable 

 amount of wind, prior to August 22, was on August 18. 

 Flowers were watched, in another field during this wind, 

 the wind was not found to trip any appreciable percentage 

 of the open flowers. During the period of August 19 to 

 22 inclusive, when nearly all of the flowers which opened 

 became tripped, there was no wind blowing sufficiently 

 strong to cause the plants to sway enough to distur"b the 



(38) 



