218 THE UNIVERSE. 



fifty to a hundred. After having left the egg, the young 

 larvae, in order to nourish themselves, excavate all the little 

 galleries which branch out from the whole length of the 

 central gallery. It is towards the extremity of these that 

 they undergo their metamorphosis, arid when their arrival 

 at the state of the perfect insect takes place, and the desire 

 to breathe the pure air comes upon them, they bore through 

 the bark, and scatter themselves abroad. 



Of all these wood-cutters, the Typographer Bostrichus is 

 regarded by M. Ratzeburg as the most dangerous. He says 

 that it ravages the forests of fir-trees in such a manner 

 that often not a single tree escapes its attacks. It is doubt- 

 less in order to give an idea of the extent of its depreda- 

 tions that this naturalist has bestowed on such a little insect 

 the alarming name of the " great pine-gnawer." Next to 

 it must also be placed the Curved-Tooth Bostrichus and the 

 Pine Hylesinus, which are almost identical with it in their 

 habits. 



Each organ has its enemy. That our apples and plums 

 are gnawed and injured by worms is no wonder, as their 

 soft tissue admits of such mischief being done with the 

 greatest ease ; but fruits so hard and well protected as those 

 of the Coniferae would seem as if they ought to be safe from 

 such attacks. This, however, is certainly not the case. 

 The progeny of certain very small butterflies, that of the 

 Cone Pyralis in particular, delight in gnawing and destroy- 

 ing the strong scales of these cones. They hollow out gal- 

 leries in their axis, and from thence spread out between 

 the scales. 



