126 HETEROSTYLED DIMORPHIC PLANTS. CHAP. III. 



series of experiments (1864) I did not suppose that this 

 curious arrangement of the flowers would have any 

 influence on their fertility; and in several instances 

 only one of the two flowers in a pair was fertilised; 

 and a large proportion or all of these failed to produce 

 berries. In the ensuing year both flowers of each 

 pair were invariably fertilised in the same manner; 

 and the latter experiments alone serve to show the 

 proportion of flowers which yield berries, when legiti- 

 mately and illegitimately fertilised; but for calculating 

 the average number of seeds per berry I have used those 

 produced during both seasons. 



In the long-styled flowers the stigma projects just 

 above the bearded throat of the corolla, and the 

 anthers are seated some way down the tube. In the 

 short-styled flowers these organs occupy reversed posi- 

 tions. In this latter form the fresh pollen-grains are 

 a little larger and more opaque than those of the long- 

 styled form. The results of my experiments are given 

 in Table 21. 



It follows from this table that 88 per cent, of the 

 paired flowers of both forms, when legitimately fer- 

 tilised, yielded double berries, nineteen of which con- 

 tained on an average 4.4 seeds, with a maximum in 

 one of 8 seeds. Of the illegitimately fertilised paired 

 flowers only 18 per cent, yielded berries, six of which 

 contained on an average only 2.1 seeds, with a maxi- 

 mum in one of 4 seeds. Thus the two legitimate 

 unions are more fertile than the two illegitimate, ac- 

 cording to the proportion of flowers which yielded ber- 

 ries, in the ratio of 100 to 20; and according to the 

 average number of contained seeds as 100 to 47. 



Three long-styled and three short-styled plants were 

 protected under separate nets, and they produced alto- 

 gether only 8 berries, containing on an average only 



