RED CLOVER. 79 



insects, whether they reach the nectar or not, will perform cross-fertiliza- 

 tion." 



In a former report for 1882, which is now scarce and hard to get, 

 I reported various experiments of my students, together with some made by 

 myself to show that 



BUMBLE BEES ARE A GREAT AID IN FERTILIZING THE FLOWER OP RED 



CLOVER. 



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. No insects were seen about either, except what are men- 

 tioned below: 



On June 29fch, a bumble 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 bumble bees were introduced, and were seen to Avork 

 on the flowers. 



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

 seeds carefully shelled and counted. The fifty heads on the plant where the 

 bumble bees were excluded yielded seeds as follows: 



40 heads yiel 

 6 " 

 1 



1 •• 

 1 

 1 



Total 



led 



one each .-. 6 



2 



, 5 



9 



The fifty heads on the plant where bumble bees were inserted and seen to 

 work under the netting, yielded seeds as follows: 



25 heads yielded 



2 " " one each 2 



5 •' " twoeach 10 



3 • • ' ' tliree each , 9 



3 •• " foureach... 12 



3 •' '* five each ■_ _ 15 



1 •' " seven. 7 



1 '* " eight 8 • 



1 •' •' nine 9 



1 •' " ten 10 



1 ■• " twelve 12 



Total 94 



In the above experiment, both lots of heads were covered alike with net- 

 ting, that no one could say the difference in yield of seed was due to the 

 fact that one lot was covered and the other not covered. 



Above, it will be observed that where the bees were seen to work on the 

 flowers the yield of seeds was nearly four times that where the bees were 

 kept away. But j^erhaps the two plants would not have yielded the same 

 number of seeds had they been treated in every way precisely alike. In 

 reply to this suggestion, I can offer the following, which shows that in six 

 examples selected at random, only one was found in which the yield of 

 seeds was nearly twice the number found in the heads containing the fewest 

 seeds. 



