INSECTS AND MANKIND 427 



storage conditions, roasted by dry heat or scalded with 

 steam, poisoned by fumigation with carbon disulphide or 

 hydrocyanic gas, or killed by exposure to powerful Rontgen 

 or ultra-violet rays. 



The Ptinidae, as already mentioned, include many species 

 commonly found in human dwellings, and among these 

 some that feed on wood are of special interest. Probably 

 before the advent of man the insects now known as the 

 Furniture Beetle {Anohium striatum) and the Death-watch 

 (Xestobium tesselatum) lived in old tree-stumps, having 

 become adapted to feed on wood long dead and too dry 

 for the sustenance of most boring insects. From such 

 habitations it was natural to migrate as occasion offered, 

 into wooden articles in houses or into the timber used in the 

 construction of the habitations themselves. Thus we find 

 chairs, tables, and other articles of furniture bored internally 

 and with little circular holes at the surface that fit accurately 

 the almost cylindrical form of the beetles as they emerge. 

 Or the beams of wonderful and valuable oaken roofs like 

 that of Westminster Hall become so badly damaged by 

 generations of Xestobium carrying on their activities through 

 centuries that the structure can only be saved from collapse 

 by complete renewal of some parts and drastic treatment 

 of others. A curious incidental result of the association 

 between these beetles and mankind is the imitation by 

 makers of sham antique furniture of the " shot- holes " 

 which in many truly ancient chairs and tables witness to 

 the former presence of families of Anobium inside their 

 legs and frames. Not that such genuine scars in timber 

 are by any means a certain indication of the venerable 

 standing of the piece that shows them ; they are often 

 apparent enough in the cheap products of the modern 

 " complete furnishing " factory. The name '' death- 

 watch," long ago applied to Xestobium and other timber- 

 feeding beetles of the family, is well known to be due to the 

 regular tapping made by the beetles with their mandibles 

 on the walls of their galleries ; such tappings were naturally 

 noticed by night watchers at bedsides of the sick and dying. 



