PHANEROGAMIA. 271 



646. In the Sundews (Fig. 147), which are common little 

 bog-plants, the leaves have many stalked glands which 

 secrete a sticky suhstance. These glands are sensitive, and 

 when an insect comes in contact with one or more of them 

 and is held fast, the others slowly bend towards the insect, 

 and the leaf itself rolls up, completely surrounding the un- 

 fortunate victim. An acid fluid is produced by the glands, 

 and by this the insect is dissolved and afterwards absorbed 

 by the leaf-tissues. In midsummer it is no uncommon 

 thing to find several of these leaves with insects upon 

 them. 



547. The Carolina Fly-trap (Fig. 148), or Venus's Fly- 

 trap as it is frequently called, is one' of the most remarka- 

 ble plants known. It is a native of a small district near 

 Wilmington, North Carolina, but is now grown considera- 

 bly as a curiosity in conservatories. Each leaf has a 

 rounded blade fringed on the sides with a row of stiff 

 points or spikes. Upon each half of the leaf there are 

 generally three sensitive hairs, and when these are touched 

 the sides quickly close together, and the stiff marginal 

 spikes interlock like the teeth of a rat-trap. " The upper 

 surface of the leaf is thickly studded with minute glands 

 of a reddish or purplish color" (Darwin). These secrete 

 an acid fluid which has the power of digesting insects and 

 other nitrogenous matters. When an insect happens to 

 alight upon a leaf and touches one of the sensitive hairs 

 the trap closes so quickly upon it that it is almost invaria- 

 bly caught and securely held, its struggles only serving to 

 increase the vigor of the grasp in which it is held. After 

 a while the digestive fluid is poured out by the glands, and 

 in this the insect is gradually dissolved. In this way the 

 leaf -tissues absorb the insect, and are doubtless nourished 



