Toecome automatically tripped; a-nd that under some condi- 

 tions, the flowers on a portion or all of the alfalfa 

 plants "become self -tripped in large numhers. Ohservations 

 made at Chinook, Montana lead the writer to the conclusion 

 that the large crops of alfalfa seed which are jroduced 

 there in certain seasons, develop chiefly from flowers 

 which have become automatically tripped. 



Observations made at Pullman, indicate that in 

 comparatively rare instances, a.lfalfa flowers which have 

 not been tripped may produce pods. However, the numbers 

 of pods and seed developing from untripped flowers 

 evidently is very small. 



Alfalfa flowers on a number of racemes v/ere tripped 

 by clasping the racem-es between the pages of a book. 47.1 

 percent of the flowers on these racem.es were tripped in 

 this way, and 52.7 percent of the flowers which were 

 tripped produced pods. The results of this experiment 

 indicate that the yield of alfalfa seed might be increased 

 when insects are not present in the fields in sufficient 

 numbers to trip the flowers, by any mechanical arrangement 

 that might be devised to trip the flowers. 



An experiment was conducted at Pullma.n, Wash, in 

 September 1909, to determine for how long a period alfalfa 

 flowers remain susceptible to fertilization. It was 



(58) 



