396 THE INSECT WORLD. 



of which the first are of great size, have a cylindrical body, the 

 abdomen being attached to the thorax in its whole breadth, without 

 any pedicle. 



The insects of the genus Sirex (Fig. 378), belonging to the former 

 of these, lay their eggs in living wood, and their larvae live for many 

 years in the interior. They are to be met with in great numbers in 

 forests of pine trees, and, according to Latreille, show themselves 

 sometimes in such great numbers as to become an object of terror. 

 The female of the Giant Sirex (Sirex gigcis) possesses a long recti- 



Fig. 378. Sirex gigas. 



linear auger. The mandibles of the larvse are of great strength, and 

 are even capable of perforating lead. This fact has been observed 

 many times. In 1857 Marshal Vaillant presented to the Academic 

 des Sciences some packets of cartridges containing balls which had 

 been pierced through by the larvae of the Sirex during the sojourn of 

 the French troops in the Crimea. Some of these insects were still 

 shut up in the gallery which they had hollowed out in the metal. 

 M. Dumeril (and this was one of the last works of that venerable and 

 learned naturalist) wrote a Report on this subject, in which were 

 recorded many analogous instances. He quoted, as an example, 

 that M. le Marquis de Breme, in 1844, showed to the Socie'te 

 Zoologique many cartridges in which the balls had been perforated 



