THE SCOLYTUS. 
103 
furniture, but of rather larger diameter. When I was a very 
little 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 
SCOLYTUS. 
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 
of the wood itself, but generally cutting a tunnel between the 
