former are tipped with anthers containing pollen grains^ 

 the latter has at the top a sticky stigma from which a very- 

 slender tube leads to the base containing the ovules. In 

 order to quicken or set the seed, pollen from the anthers 

 must be deposited upon the stigma. 



The least highly developed plants fertilize themselves^ 

 that is the anthers and stigma are so located that pollen 

 falls directly from one to the other, or the stamens may 

 gradually curve inward when the pollen is ripened so as to 

 place it in contact with the stigma. 



A great many of the more highly developed plants have 

 the pistils and stamens so situated that self-fertilization is 

 impossible. In which cases it is necessary that some 

 medium transport the valuable grains from the anthers to 

 their destined places of repose. 



The great naturalist Darwin discovered that the intro- 

 duction of new stock is just as vital to a strong healthy race 

 of plants as it is among animals, and that many plants were 

 so arranged that reproduction could not take place without 

 the introduction of pollen from another blossom and, in 

 some cases, from another plant. Certain flowers are infer- 

 tile to their own pollen ; others have the pollen ripen before 

 the stigma of the same flower is in condition to receive it, 

 still others have only stamens on one blossom and anthers 

 on others, sometimes on the same and sometimes on different 

 plants. These conditions mean that pollen must be carried 

 from flower to flower or plant to plant, and the agency for 

 doing this is principally insects. Certain specialized flow- 

 ers require the assistance of certain moths, the tongues of 

 which are of just the right length to reach the store of 

 nectar and also accomplish the purpose to the flowers. The 

 big bumblebee, however, is the benefactor of a greater va- 

 riety of flowers than any other one insect. 



Bees, of all kinds, are particularly well adapted by na- 

 ture for this work. They are comparatively heavy, strong 

 and are steady workers. Butterflies flit aimlessly about, 

 often stopping to rest for hours at a time; they have no- 

 body but themselves to look after so they can dine when 



