402 THE INSECT WOELD. 



insects of leaden balls contained in cartridges prepared for war. 

 M. Milne Edwards read to the Academic des Sciences a short 

 Report on these works. 



The insect which had produced the perforations observed in 

 the balls sent to the Crimea in 1857, and which M. Dumeril par- 

 ticularly studied, was the Sirex juvencus, and had been taken from 

 France in the wood forming the boxes which contained the 

 cartridges. In the other case of which we are speaking, that is to 

 say, of the cartridges which were sent in 1861 to the Academic 

 by Captain Heriot and by M. Bouteille, the perforations had been 

 produced by another species. Mr. Milne Edwards, who found the 

 insect that had caused this strange damage, had no trouble in 

 recognising it as the Sirex gigas, which, in its larva state, lives 

 in the interior of old trees or pieces of wood, and which after it 

 has gone through all its metamorphoses, comes out of its retreat, 

 to reproduce its kind. To clear themselves a way, they cut 

 away with their mandibles the ligneous substances or other hard 

 bodies they meet with on their road. It was in pursuing this 

 object that the insects, imprisoned accidentally in the packets of 

 cartridges when they were yet only in the larva state, must have 

 attacked the leaden balls, as also the paper and the other matters 

 which they met with on their road, and which opposed their 



passage. M. Bouteille proves, in his Me- 

 moir, that M. Dumeril had committed an 

 error in saying that the perforating organ 

 employed by the Sirex to attack the leaden 

 balls in the cartridges in the Crimea was 

 the auger situated at the extremity of the 

 abdomen of the female, and intended for 

 cutting into that part of the wood where 

 it is to lay its eggs. M. Bouteille has 

 established, in fact, that they were not 

 only the females which attacked the car- 

 Fig. 379.-Larva of a Saw-fly tridges, but that the males, which have no 



auger, had occasioned the same damage. 



The Tenthredinetce are called "saw-flies," because the females 

 are furnished with a double auger, notched like a saw, with 

 which they cut into the vegetables in which they lay their eggs. 



