MOUNTAIN TREES 



crease their absorptive area and continue 

 indefinitely their ability to absorb 

 water. 



In exchange for this valuable service, 

 the fungus, acting as a parasite, exacts 

 by means of its delicate, branching fila- 

 ments which penetrate the root cells of 

 the host, a toll of food for itself. Such 

 a mutual and beneficial partnership is 

 known as a symbiosis. 



There is a beetle, a portion of whose 

 life history is intimately bound up with 

 the dying days of many of the forest 

 trees. This is the big Pine Borer, 

 Prionus calif ornicus, who is responsible 

 for the big holes and tunnels in the dead 

 and fallen logs of the pines and firs. The 

 adult forms are familiar sights at night 

 about mountain resorts. They fly into 

 open doors and windows, annoucing 

 their arrival by a great clattering of 

 wings. The curious who try to pick 

 them up find that the big, brown-bodied, 

 long-horned creatures are possessed of 

 powerful, vicious, incurved mandibles 



38 



