216 THE UNIVERSE. 



belonging to the genera Bostrichus and Hylesinus. Their 

 teeth, with deadly quickness, cut numerous galleries be- 

 tween the wood and the bark, so that both portions of the 

 tree are assailed at the same time. These tiny ravagers are 



108. Nuptial Chamber of the Pine Hylesinus, of natural size, and the Insect enlarged. 



often not more than about the sixth of an inch long, and 

 hence, as their bodies are slender in proportion, they only 

 require a very narrow trench to promenade in at their ease. 

 Nevertheless, as each insect reproduces its species very 

 rapidly, the number of galleries hollowed out by a single 



