218 



ELEMENTARY STUDIES IN BOTANY 



insects. Plants with such leaves are often called " carnivo- 

 rous plants " or " insectivorous plants/' since the captured 

 insects are used for food. This is merely one way of getting 

 protein food without manufacturing it, and at the same time 

 such leaves are usually green and 

 manufacture their carbohydrate 

 food. Three conspicuous illus- 

 trations of insect-catching leaves 

 will be given. 



The " pitcher-plants " are so 



FIG. 185. Leaves of the common northern 

 pitcher-plant, one of them cut across to 

 show cavity and wing. After GRAY. 



FIG. 186. Leaf of a southern 

 pitcher-plant, showing the fun- 

 nel form and winged pitcher, 

 and the overarching hood with 

 translucent spots. After 

 KEENER. 



named because the leaves form tubes or urns of various 

 forms, which contain water, and to these pitchers insects 

 are attracted and then drowned. The common pitcher- 



