THE EVOLUTION OF THE FLOWER 123 



grains, which, coming into contact with the ovules 

 in the female portion of the flower, bring about 

 the process of fertilisation. If all goes well the 

 outcome of this union is the seed the forerunner 

 of the new plant. 



It may not seem to be a particularly easy 

 matter at first sight to determine what may be 

 the origin of the specialised male and female 

 organs of the plant. As we have seen, both the 

 sepals and petals of the flower show a more or 

 less striking resemblance to the foliage of the plant, 

 but one can scarcely say that there is much obvious 

 connection between stamens, pistil, and leaf. None 

 the less is it a fact which can be easily demon- 

 strated that the leaf was the ancestor of even the 

 reproductive organs themselves. In this con- 

 nection the case of the so-called " double " flowers 

 is very instructive. Here we see that the pecu- 

 liarity of the blossom consists in a great increase 

 in the number of petals, and these organs must 

 have had their origin in something ; as a matter 

 of fact, they are degenerate stamens. The 

 manner in which this change of stamens into 

 petals takes place may be often well seen in the 

 case of Begonias. It has been found to be almost 

 impossible to establish an entirely double strain 

 of these flowers owing to a strong tendency to 



