PLANTS DEFEND THEMSELVES 48 
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 larve and 
other small aquatic life, they have developed sting- 
