232 HABITS AND INSTINCTS OP ANIMALS. CHAP. VII. , 



American blight, which covers itself with a cottony 

 substance exuding from the pores of its own body, 

 compasses the destruction of many thousands of the 

 trees on which it dwells, taking up its abode in the 

 bark, and continually drawing away the sap. A small 

 beetle (Bostrichus typographus Fab.), however, occasions, 

 in Germany, still greater mischief. In its preparatory 

 state, it feeds upon the soft inner bark of the fir ; but 

 it does this in immense numbers, 80,000 being some- 

 times discovered in one tree; and " such is its vitality, 

 that though the bark be battered, and the tree plunged 

 into water, or laid upon the ice or snow, it remains 

 alive, unhurt.". In 1783, the number of trees de- 

 stroyed by this insect, in the Hartz forests alone, was 

 calculated at a million and a half.* The locust (fig. 

 69.), however, that pest of Eastern countries, is yet 



more destructive, as our former remarks, under the head 

 of Migration, will abundantly prove. On a cursory 

 glance at this insect, we could scarcely believe it capable 

 of inflicting such misery upon mankind. Certain it is, 

 however, that these animals may be considered among 

 the most dreadful plague to which some countries, and 

 Africa particularly, is exposed ; and from which most 

 parts of Europe have not been free. From 1778 to 

 1780, the whole empire of Morocco was laid waste by 

 swarms of locusts, so that a severe famine ensued, 

 which destroyed numbers of the inhabitants. The 

 whole country was covered with them ; every particle 

 of vegetation disappeared; and when, at length, they 

 were carried, by a hurricane, into the Western Ocean, 



* Int. to.Ent. voL i. p. 21. 



