__SIBMAEY_ __ 



Of the flowers olsserved on a large nuiaber of alfalfa 

 plants at Pullinan, Wash., and at Chinook and Havre, ]";ont . , 

 in 1908, 1909 and 1910, 23.5 percent of those flowers 

 which developed under natural conditions produced seed, 

 fhen honey-gathering insects were excluded hy means of 

 fine-meshed mosquito netting, the nuraher of flowers pro- 

 ducing seed was reduced to 7,57 percent. Of those flowers 

 from which insects were excluded, which were artificially 

 tripped, 36.07 percent produced seed. The pods which 

 developed from flowers which were open to the access of 

 insects contained an average nuraher of 3.09 seeds each; 

 the pods developing from flowers from which insects were 

 excluded contained 2.24 seeds each, and the flowers art- 

 ificially tripped produced pods containing 2.22 seeds 

 each. 



■When alfalfa flowers were protected from the sun and 

 wind hy one thickness of mosquito netting iDut were access- 

 ihle. to insects, the percentage of flowers which produced 

 pods and seed was not arpreciahly different than the per- 

 centage of flowers producing pods and seed when conditions 

 were natural. These results indicate that the single 

 thickness of mosquito netting which was placed on a 

 portion or all of the plants in the various experiments 



(53) 



