27 



M. Mains; 25 flowers, 13 fruits; 35 flowers, 18 fruits; 58 flow- 

 ers, 38 fruits ; 60 flowers, ^^y fruits (see figure 4). 



M. Sargentii; 45 flowers, 39 fruits; 58 flowers, 41 fruits; 60 

 flowers, 45 fruits; 72 flowers, 57 fruits; 141 flowers, 135 fruits. 



These three trees produced fruits in abundance but the pro- 

 portion of flowers setting fruit and the size of the fruit seemed 

 to be as good for the enclosed branches as for those subject to 



Figure 2. Above are shown the mature fruits on a branch of the 

 same tree (see figure i) subjected to open cross-pollination. 



The tree was able to produce fruits in abundance when there was a 

 compatible cross-pollination. Its own pollen is potent but is incom- 

 patible in self-fertilization. 



open poHination. These plants appeared to be fully self-com- 

 patible. 



For another group of trees the number of enclosed flowers 

 that set fruit was relatively very low. These plants appeared 

 to be feebly self-compatible. The data for these are as follows : 



