220 THE UNIVERSE. 



to such an extent that it is necessary to exterminate them 

 utterly in order to preserve the forest from ruin. In one 

 part the Avoodmen and their famihes, who are called out 

 en masse, are only occupied in crushing this deadly race 

 upon the trees. In another the others are cutting off" the 

 infected districts by ditches, in order to check the inva- 

 sion of the caterpillars, which, when they have devoured 

 everything in one place, proceed in immense bands to 

 invade the healthy localities. 



But in spite of so much labour, man is sometimes 

 vanquished by the insect, and there only remains one 

 extreme resource — that of setting fire to the forest and 

 burning the invaders. 



All this war of extinction, of which we have just given 

 a succinct account, is only directed against a small number 

 of our enemies, as for the most part they are able to evade 

 the empire of the agriculturist, and their formidable army 

 defies our weakness. 



These great Avorks are particularly undertaken against 

 certain night-moths, for they are simple PhalaBni?e, which 

 are to be classed among the most destructive ravagers of 

 the forests. They are attacked in their three different 

 phases; their caterpillars are crushed as they climb the trees. 



When after devouring a complete section of the wood, 

 they pour forth in serried columns to attack a sound part, 

 they fall into trenches hollowed out by the pioneers, and 

 when they fill these, they are stifled in a heap by covering 

 them over with earth. The great fires lighted at night are 

 directed against nocturnal Phaltenfe. The glare attracts 

 them, and they are soon scorched by the flame in conse- 

 quence of going too near it. 



The Pine Bombyx enjoys the sad prerogative of being 

 placed in the front rank of the enemies of our forests. It 



