PLANTS DEFEND THEMSELVES 43 



that attempts to take any thorned plant's treasure 

 by storm will find the first steps easy, but as he pro- 

 gresses nearer and nearer to the goal, the opposing 

 points become more numerous, until the way at last 

 becomes impassable. No matter how the worm 

 turns, a hard point of needle sharpness waits to 

 impale him. The familiar thistle is such an armed 

 force, a thing dreaded of robber insects and vora- 

 cious animals alike, for its cruel, dagger points ; yet 

 the pollen-bearing honey-bee rests in a soft bed of 

 purple down and drinks his fill unheeding and un- 

 troubled by the bristling, impregnable armament 

 which makes his source of supply inaccessible to the 

 marauders below. 



The tar-flower (Bejaria racemosa), growing as 

 it does in the pine barrens of the Southern States, 

 without its armour of prickly hairs would stand 

 little chance of survival. Its blossoms are a dainty 

 white with a delicate pinkish tinge, and its leaves 

 are a glossy olive-green. Grazing animals have 

 learned to give it a wide berth on account of its 

 prickles, and thus it is allowed to flourish unmo- 

 lested. 



Aquatic plants meet with a different type of 

 insect foes, but their means of defence is largely 

 similar to that of land plants. Against larvae and 

 other small aquatic life, they have developed sting- 



