

i 



102 HETEROSTYLED DIMORPHIC PLANTS. Chap. III. 



of fruit, but the fruits themselves yielded a slightly 

 lower average number of seeds than did the long-styled 

 plants. The results of Hildebrand's experiments on 

 the fertility of the two forms are given in the follow- 

 ing table : 



Table 19. 

 ' Pulmonaria officinalis (from Hildebrand) 



Nature of Union. 



Number 



of 



Flowers 



fertilised. 



Number 



of 



Fruits 



produced. 



Average 



Number of 



Seeds per 



Fruit. 



Long-styled flowers, by pollen of short- j 



14 



10 



1.30 



Long-styled flowers, 14 by own pollen, ") 

 and 16 by pollen of other plant of same > 



30 







1 







Short-styled flowers, by pollen of long- ) 



16 



14 



1.57 



- ■ ' 



Short-styled flowers, 11 by own pollen, 14 1 

 by pollen of other plant of same form. > 



25 











In the summer of 1864, before I had heard of Hilde- 

 brand's experiments, I noticed some long-styled plants 

 of this species (named for me by Dr. Hooker) growing 

 by themselves in a garden in Surrey; and to my sur- 

 prise about half the flowers had set fruit, several of 

 which contained 2, and one contained even 3 seeds. 

 These seeds were sown in my garden, and eleven 

 seedlings thus raised, all of which proved long-styled, 

 in accordance with the usual rule in such cases. Two 

 years afterwards the plants were left uncovered, no 

 other plant of the same genus growing in my garden, 

 and the flowers were visited by many bees. They set 

 an abundance of seeds; for instance, I gathered from a 

 single plant rather less than half of the seeds which it 

 had produced, and they numbered 47. Therefore this 



