FLOWERS 



189 



Method. Study the flower, making note of its color, 

 odor, and peculiarities of form. Hunt for nectaries and spe- 

 cial structures, such as 

 spurs, nectar guides, 

 etc., which aid insects 

 in their work of pol- 

 lination. Look for 

 special devices which 

 prevent the entrance 

 of unwelcome visitors. FlQ - 81.; Flower and moth. 



Take a position near the plant and await the coming of 

 an insect visitor. Observe what insects come, how they 

 alight upon the flower, how they enter it, and whence they 



FIG. 82. Pollination of Salvia glutinosa. 1, a stamen. The upright column 

 to the left of / is the filament, c, c, the connective, anther bearing above 

 and sterile below. 2 and 3, longitudinal diagrams of a young flower, show- 

 ing the anther in its natural position in 2, and pushed down by a bee by 

 pressing on the lower part of the connective in 3. 4, a bee visiting a 

 younger flower ; the anthers pushed down upon its back. 5, a bee visiting 

 an older flower ; the style having become elongated and pendent touches 

 the bee's back. After KERNER. 



go on leaving it. Can a bee enter and leave a flower without 

 touching the stamens and pistils? 



