Chap. IV. LYTHRUM SALICARIA. 153 



Besides the above experiments, I fertilised a con- 

 siderable number of long-styled flowers with pollen, 

 taken by a camePs-hair brush, from both the mid- 

 length and shortest stamens of their own form; only 

 5 capsules were produced, and these yielded on an 

 average 14.5 seeds. In 1863 I tried a much better 

 experiment: a long-styled plant was grown by itself, 

 miles away from any other plant, so that the flowers 

 could have received only their own two kinds of pol- 

 len. The flowers were incessantly visited by bees, and 

 their stigmas must have received successive applica- 

 tions of pollen on the most favourable days and at the 

 most favourable hours: all who have crossed plants 

 know that this highly favours fertilisation. This plant 

 produced an abundant crop of capsules; I took by 

 chance 20 capsules, and these contained seeds in num- 

 ber as follows : — 



20 



20 



35 



21 



19 



26 



24 



12 



23 



10 



7 



30 



27 



29 



13 



20 



12 



29 



19 



35 



This gives an average of 21.5 seeds per capsule. As 

 we know that the long-styled form, when standing 

 near plants of the other two forms and fertilised by 

 insects, produces on an average 93 seeds per capsule, 

 we see that this form, fertilised by its own two pollens, 

 yields only between one-fourth and one-fifth of the full 

 number of seeds. I have spoken as if the plant had 

 received both its own kinds of pollen, and this is, of 

 course, possible; but, from the enclosed position of the 

 shortest stamens, it is much more probable that the 

 stigma received exclusively pollen from the mid- 

 length stamens; and this, as may be seen in com- 

 partment V. in Table 23, is the more fertile of the two 

 self-unions. 



