1 5 8 Plants and their Ways in South Africa 



have not wholly revealed themselves until they are past 

 pressing. 



The pleasure in knowing a flower's structure and plan is 

 increased when we learn a meaning of the endless variety of 

 forms and markings from patient watching or from reading what 

 others have found. Long after flowers had been studied and 

 their parts described the use of pollen remained a mystery. At 

 last, in 1682, an English botanist, Nehemiah Grew, discovered 

 that before seeds were produced pollen must be transferred 

 to the stigma. No one believed him, nor did he know just 

 why it was so. Fifty years later Linnaeus, the Swedish botanist, 

 said it was true, and then people began to think it must be 

 so. It is hard to believe what we do not understand. Even 

 the great Linnaeus had not found out all, and it was thought 

 that pollen was necessary for the ovules of the same flower, 

 since, in the Roella family, for instance, the pollen from the 

 anthers is all caught upon the bristles along the style of the 

 same flower. But even here the pollen has been brushed off 

 before the clapper-like stigmas have split open at the end and 

 exposed the part which receives the pollen if it is to be of 

 service to that flower. One man declared even that when a 

 pollen grain had been caught on a bristle it drew back and pulled 

 the pollen grain into the style. It does not, but when we 

 have wrong ideas they make us think a great many things are 

 true that are not. He thought he saw what he was so sure 

 must happen. 



Another fifty years .went by. People were carefully and 

 patiently watching, and the trum is bound to be known when 

 people are eager to know it. A German' botanist, Sprengel, 

 fornd that in most flowers the pollen caryaot rtach the stigma 

 of its own flower ; even if it is caught on the style it seldom 

 reaches the tip or sensitive part of the stigma. What he saw 

 puzzled him and others, until Darwin, seventy years later, 

 showed that nearly all flowers are so constructed that they 

 receive pollen from another flower, and so ovules are usually 

 cross fertilized. 



When pollen has been transferred from the stamens to a 

 pistil, the pistil has been pollinated. But that is not all, for 



