THE SCOLYTUS DESTRUCTOR. 



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which her body fits exactly, and bores little side alleys on either 

 side and at regular distances, and lays an egg in each. As 

 soon as the larvae are born they set to work to gnaw the wood, 



THE BARK OF AN ELM PIERCED AND MARKED BY ScolytltS destrucior. 



doing this so as to enlarge and lengthen their side alleys, and 

 they always eat away in a determinate direction. The bark 

 and the wood of the trees which have been attacked by the 

 Scolytus are marked with regular designs, which are peculiar 



