42 IOWA ACADEMY OF SCIENCE 



OBSERVATIONS "UPON WORK OF BUMBLE BEES UPON RED CLOVER. AUGUST 1908. 



Tliis list records 381 visits to flowers in 814 seconds or 1 visit in 

 about 2 seconds. 



Regarding the timing of bees' visits, from one of Lubbock's interest- 

 ing accounts we learn that a honey bee made 59 visits in 7 hours. 

 Other series of observations showed no great departure from this tim- 

 ing, about 7 minutes for each trip. 



Estimating an average of 30 heads of clover in each square foot, and 

 880 flowers in each head, that each visit requires 2 seconds, all the 

 flowers in one square foot may be visited in 1 1-3 hours. 



It is evident that the requirements of an entire field are exceed- 

 ingly great; each pollinator, however, can accomplish in the season 

 an important part toward the cross-pollination of the field of clover 



