234 INDIIIEC'T INJURIES CAUSED BY INSECTS. 



vils', have a similar appetite, but penetrate deeper into 

 the wood. The most extensive family, however, of 

 timber-borers are the Capricorn beetles, including- the 

 Fabrician genera of Prionus, Ceramhijx^ Lamia, Ste- 

 nocorus, Caloptis, Rhagium, Gnoma^ Saperda, Calli- 

 ditim, and Clytus. The larva of these, as soon as 

 hatched, leaves its first station between the bark and 

 wood, and begins to make its way into the solid timber, 

 (some of them plunging even into the iron heart of the 

 oak, and one even perforating lead^,) where it eats for 

 itself tortuous paths, at its first starting perhaps not 

 bigger than a pin's head, but gradually increasing in 

 dimensions as the animal increases in magnitude, till 

 it attains in some instances to a diameter of one or two 

 inches. Only conceive what havoc the grub of the vast 

 Prionus giganteus must make in a beam ! Percival is 

 probably speaking of this beetle, when, in his account 

 of Ceylon, he tells us, " There is an insect found here 

 which resembles an immense overgrown beetle. It is 

 called by us a carpenter, from its boring large holes in 

 timber, of a regular form, and to the depth of several 



* CitrcuUo lignarius. Marsh. lihinosimus riificoUis, Latr. 



*" The larva of a Cerambyx (which Dr. Leach has discovered to be 

 C. Bajulus, L.) sometimes does material injury to the wood- work of the 

 roofs of houses in London, piercing in every direction the fir rafters, and, 

 w hen arrived at the perfect state, making its nay out even throi'gh sheets 

 of lead one sixth of an inch thick, when they happen to have been nailed 

 upon the rafter in which it has assumed its final metamorphosis. 1 am 

 indebted to the kindness of Sir Joseph Banks for a specimen of such a 

 sheet of lead, which, though only eight inches long and four broad, is thus 

 pierced with twelve oval holes, of some of which the longest diameter is a 

 quarter of an inch ! Mr. Charles Miller first discovered lead in the sto- 

 mach of the larva of this insect. 



