336 BUMBLE BEES AS FERTILIZERS. 



The following single experiment will serve as an example: 

 Two fine bunches of the first crop of clover, apparently alike, 

 were covered with mosquito netting. IS^o insects were seen about 

 either, except those mentioned below. On June 29tli a bum- 

 ble bee was placed inside of one netting and seen to work on the 

 flowers. 



On July 10th two more bumble bees were introduced and seen 

 to work, and on July 12th more bees were introduced, and were 

 seen to work on the flowers. 



On July 31st 50 ripe heads were selected from each plant, and 

 the seeds carefully shelled and counted. The 50 heads on the 

 plant where the bumble bees were excluded yielded seeds as 

 follows : 

 40 heads yielded - -.. -.^ 



heads yielded one seed each 6 



1 liead yielded -- 2 



1 head yielded 3 



1 head yielded - 5 



1 liead yielded - 9 



Total --- ---- - --- 25 



The 50 heads on the plant where bumble bees were inserted 

 and seen to work under the netting yielded seeds as follows : 

 25 heads yielded 



2 heads yielded one each 2 



5 heads yielded two each. - . . 10 



3 heads yielded tliree each — 9 



3 heads yielded four each 12 



3 heads yielded five each 15 



1 head yielded seven - - 7 



1 head yielded eight 8 



1 liead yielded nine _. 9 



1 head yielded ten 10 



. 1 head yielded twelve 12 



Total 94 



In the above experiment both lots of heads were covered alike 



