272 BOTANY. 
by it. After a time a leaf which has caught and digested 
an insect opens again and is ready for another. In this 
connection the student may profitably read Mr. Darwin’s 
interesting book, “Insectivorous Plants,” published in 1875. 
548. A quite different class of insect-catching plants is 
Fia. 149.—Common Pitcher-plant (Sarracenia purpurea), showing leaves and 
flower; one leaf cut across so as to show the cavity. Half natural size. 
represented by the Pitcher-plants of various kinds. In the 
Common Pitcher-plant, which grows in marshes in the 
Northern and Eastern United States, the leaves are dilated 
into tubular or pitcher-shaped cavities (Fig. 149), contain- 
ing a watery fluid. The upper part of the leaf is reddish 
