THE SCOLYTUS. 



103 



furniture, but of rather larger diameter. When I was a very 

 Httle boy and first saw these holes, I thought that they had been 

 made by shot, and in trying to pick out the shot with my knife, 

 made the discovery that the holes were not due to firearms, but 

 to insects. 



If the bark be cut through, and then raised with the knife, the 

 curious radiating system of tunnels will be exposed to view, and 

 the observer will notice that, however these tunnels may vary 



in size and direction, they all agree in these points ; firstly, that 

 they radiate nearly at right angles from a single cylindrical 

 tunnel ; and secondly, that they are very small at their base, and 

 gradually increase to their termination. The cause of this forma- 

 tion is as follows : — 



The mother insect enters the bark in search of food, and 

 burrows deeply into the tree, sometimes boring into the substance 

 Cff the wood itself, but generally cutting a tunnel between tlie 



