CAKE AND PROTECTION OF THE FOREST 121 



injured, sickly, or dying trees make it especially "easy 

 for beetles to get food and multiply, that they become 

 really dangerous. 



From this it is clear that a well-kept piece of woods, 

 where all trees are thrifty and the puny, crippled, or over- 



FIG. 45. Scale Insect on White-Pine Leaves 



At 2 a is a bunch of ordinary leaves for comparison; 2, twig and stunted leaves 

 covered by scale insect; 26, 2c, female, and 2d, male of scale insect (enlarged) 



ripe trees, and also all dead timber, are regularly cut out, 

 is not likely to be infested by bark beetles. Should they 

 come from a neighboring badly kept piece of woods, the 



