perhaps be subject to the criticism that the flowers 

 fertilized with their o\7n pollen should have been tripped 

 with pieces of rough string, as the flowers fertilized 

 v.ith pollen from separate plants were, instead of with 

 a smooth plant stem or by pressure; for the irritation 

 of the stigma with the rough string may possibly have 

 had some influence upon the development of the flowers 

 into pods. 



In 1910 an experiment was conducted in which 

 flowers which were fertilised with pollen from other 

 plants, as in the experiment just described, were com- 

 pared with flowers which were artificially fertilized 

 with pollen from other flowers of the same plant. The 

 flowers fertilized in each of these tv^o ways were 

 tripped in the same manner, by using a piece of alfalfa 

 stem Yi?ound with thread. The results of this experiment 

 are fi:lven in Table IX. 



21 - 



