THE NUTRITION OF PLANTS. 



159 



the water, and if it attempts to escape by crawling up the 

 sides of the urn, the thicket of downward-pointing hairs 

 prevents. If it seeks to fly away from the rim, it flies 

 towards the translucent spots in the hood, which look like 

 the way of escape, as the direction of entrance is in the 

 shadow of the hood. Pounding against the hood, the fly 

 falls into the tube. This Southern pitcher plant is known 



Fig. 150. Two leaves of a sun-dew. The one to the right has its glandular hairs 

 fully expanded ; the one to the left shows half of the hairs bending inward, in the 

 position assumed when an insect has been captured. — After Kerxer. 



as a great fly-catcher, and^the urns are often well supplied 

 with the decaying bodies of these insects. 



A much larger Californian pitcher plant has still more 

 elaborate contrivances for attracting insects (see Fig. 148). 



(2) Drosera. — The droseras are commonly known as 

 u sun-dews," and grow in swampy regions, the leaves form- 

 ing small rosettes on the ground (see Fig. 149). In one 

 form the leaf blade is round, and the margin is beset by 

 prominent bristle-like hairs, each with a globular gland at 

 its tip (see Fig. 150). Shorter gland-bearing hairs are 



