J04 STRANGE DWELLINGS. 



wood and the bark. She then deposits her eggs regularly along 

 the cylindrical tunnels, and in most cases retreats to the entrance, 

 and there dies, her body forming a natural stopper. In due time 

 the eggs are hatched, producing a number of very minute white 

 grubs, which immediately begin to feed, the substance of the 

 tree being the only diet of this insect in every stage of existence. 

 Urged by a wonderful instinct, each grub arranges its body at 

 a right angle with the burrow in which it was hatched, and so 

 eats its way steadily outwards. 



When the grubs have made some progress, the wisdom of this 

 arrangement becomes evident. As they increase in size, the 

 burrows necessarily increase with them, so that if they had all 

 started parallel with each other, the tunnels would coalesce and 

 the grubs be unable to procure their proper amount of food. As, 

 however, the tunnels radiate like the spokes of a wheel, they 

 very seldom interfere with each other, their radiation more than 

 keeping pace with their increasing size. It will easily be seen 

 by reference to the illustration, that if a number of these beetles 

 attack a tree, the bark is gradually separated from the woody 

 portion, and that, as in all exogenous trees the nourishment is 

 derived from the bark, the tree must die as soon as the functions 

 of the bark are suspended. 



The well-known * worm-eaten ' appearance of furniture is 

 caused by certain beetles belonging to another family. As may 

 be seen from the dimensions of the tunnels, the insects are very 

 small, and their bodies are nearly cylindrical. The ravages which 

 these beetles cause are fatal to all who happen to possess old 

 furniture, but Mr. Westwood mentions that one common species, 

 PHliftus pectinicornisy completely destroyed a new bedpost, in 

 the short space of three years. There is but one known method 

 of killing the insects which have already taken possession, and 

 of preventing others from following their example, namely, 

 by injecting a solution of corrosive sublimate into the holes, 

 and then treating the whole of the surface with the same 

 poisonous liquid. I need perhaps scarcely mention, that insects 

 which are popularly called Death-watches, belong to this 



