FROM THE ATTACKS OF ANIMALS. 139 



these plants are so stiff and hard that we should 

 hardly think they would tempt animals to eat 

 them. But "Hunger is a stern master," and expe- 

 rience shows that they are eaten. Not to be wholly 

 at the mercy of such attacks, these leafless green- 

 stemmed plants are often armed, especially by the 

 ends of their green branches running out into 

 spines, bristling against the assailant. Indeed, 

 many of these plants are built up wholly of 

 many-branched green thorns, which gives them a 

 very singular appearance. 



But the weapons formed on leaves are far more 

 numerous than those with which green stems are 

 provided. Sometimes sharp points proceed from 

 the ends of the ribs and veins which make the leaf 

 framework ; sometimes they are formed of cells or 

 groups of cells which originate in the epidermis 

 of the leaf and stand out, now from the surface, 

 now from the margin, like little daggers. 



In the Southern Alps is found a species of grass 

 (Festuca alpestris), growing in some places very 

 abundantly. Its stiff leaves, which stand out in 

 every direction, end in sharp points. This grass 

 is more hated than any plant in the whole region, 

 and the shepherds try to destroy it wherever it 

 grows in any quantity. Grazing animals seeking 



