168 



HOMES WITHOUT HANDS. 



boring tool, whether under the name of auger, gimlet, or centre-bit, 

 and it will be found that the harder the substance into which the 

 insect burrows, the more cylindrical is its shape. The dors, 

 clocks, and other earth-boring beetles, depart from that form, but 

 when we come to look at the scolytus, the ptinus, and other 

 wood-borers, we cannot but notice how very cylindrical they are in 

 their shape. 



Perhaps there is no wood-boring beetle which is known so 

 well as the little insect which is called Scolytus destructor. I am 

 not aware that it has a popular name that will distinguish it 

 from other small beetles which bore into wood. 



The accompanying illustration will probably call to the mind of 

 the reader, the insect which now comes before our notice. If he 

 should have examined the bark of certain trees, particularly that 

 of the elm, he will often have seen that it is perforated with 

 circular holes, very like those which are drilled into worm-eaten 

 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, hut 



