182 INVERTEBRATE ANIMALS. 



metallic, colours, and their voracious habits, though many of them 

 feed upon vegetable matters. 



Of the enormous number of known Beetles, the only one which 

 can be said to be of any decided use to man is the so-called Blister- 

 beetle," or " Sjianish Fly " {Cnntharis vesicatoria). This handsome 

 insect is a native of Southern Europe, especially of Italy, Spain, and 

 France, and lives upon the leaves of the ash, lilac, elder, and poplar. 

 It is largely collected and exported for medicinal purposes, as it 

 yields one of the most generally used and efficient of blisters. 



Many of the Coleoptera inflict great injury upon wild or cultivated 

 plants, some of them being most destructive in their adult condition, 

 while others do most harm in their larval state. It is to be remem- 

 bered, however, that the CoJeoptera, like the Diptera, discharge 

 important and highly beneficial functions by destroying vast quan- 

 tities of decaying organic matteuy which would otherwise prove 

 injurious to man. 



