30 SOUTH AFRICAN FLOWERING PLANTS. 



all sorts of crosses the mid-styled proved to be the 

 most prolific. 



The form of this Ox'alis described as occurring in 

 the Northern Hemisphere around the Mediterranean 

 Sea is the short-styled form only. It might be thought 

 that the pollen must fall upon the stigmas ; and no 

 doubt it does, but it cannot fertilize the ovules, though 

 it may pollinate those stigmas. 



This impotence to fertilize has been discovered in 

 other flowers. Thus there is a kind of flax, wild in 

 England, which has not three, but only two forms of 

 flowers, which will not set seed unless they be crossed. 

 If pollen be placed upon the stigma of the same flower, 

 it fails to set seed, but it sets the full amount, i.e. ten 

 seeds, if used for the other kind. 



As an example to show that these differences can 

 be broken down, an Englishman, who settled in 

 Pennsylvania of the United States of America, took 

 a plant of this flax with him. As he had only one 

 kind, it never set any seed for fourteen years. In the 

 fifteenth year he was surprised to see a rod of pods 

 on one branch. Examining the flowers, he found that 

 the style and stamens were the same length, and that 

 the anthers were pollinating the stigmas, producing 

 self-fertilization. Why they suddenly acquired this 

 power he could not find out. 



In this respect it became like the true Flax plant, 

 which supplies the fibre for making linen; for this 



