found that up to the time when the experiment ended, 

 seven days after the flowers opened, when the tips of the 

 petals were "beginning to wilt, there was pra.ctic8lly no 

 diminution in the ahility of the flowers tripped to 'become 

 fertilized. 



The percentage of flowers visited which are tripped 

 by different kinds of honey-gathering insects varies 

 greatly. It was found that dom-estic honey "bees usually 

 trip onlj'' ahout one percent or less of the flowers. 

 Different species of bumhlehees vary in their efficiency 

 in tripping flowers; at Havre, Mont., several different 

 species ViThich were observed tripped an average of 29.4 

 percent of the flowers that they visited for honey. Wild 

 bees of the Megachile species tripped over 90 percent of 

 the flowers which they were observed to visit. Observat- 

 ions of the small thrips which were common on the alfalfa 

 flowers in Washington and Montana, leads to the conculsion 

 that these insects neither appreciably increese or de- 

 crease their percentage of flowers producing pods and 

 seed. An experiment conducted at Pullman, Wash, indicates 

 that night-flying insects are not an important factor in 

 influencing the development of the alfalfa seed crop- 



It was found that there is a considerable amount of 

 variation in the percentage of flowers producing pods and 

 in the number of seeds per pods, on different alfalfa 



(59) 



