30 NORTH AMERICAN INSECTS. 



the one undoing what the other does; the injuries which 

 one species would inflict upon man are checked by other 

 species, which prevent their superabundance, and keep an 

 even balance in the scale of being. 



Hence this law of antagonization is, in its effects, the 

 law of Compensation. Thus we see Tiger Beetles, Carabi, 

 Lady-birds, and many other Coleoptera, destined to benefit 

 mankind by devouring other insects which are noxious. Of 

 these we have already spoken. But a mere negative use- 

 fulness is not the only one belonging to this order. There 

 are also many other Beetles which render us the greatest 

 service by devouring putrid substances, carrion, decomposed 

 fermenting plants, mushrooms, dung, and decayed wood, as, 

 for instance, the Dung Beetles, Carrion Beetles, and many 

 others. 



Now the food of Beetles in general has suggested to us 

 the idea of dividing them into three Natural Families, ac- 

 cording to the nourishment which they subsist upon, and 

 this division seems to us the simplest, most uniform, and 

 the most rational, as well as the only really natural divi- 

 sion. Accordingly, I classify all the Coleoptera under one 

 of the three following families : 



1. Carnivorous Beetles, which, like Lions and Tigers among Beasts, 

 prey upon living Insects ; as presented in Figure 3. 



2. Scavenger Beetles, which live on putrid matter, carrion, decayed 

 wood, and plants ; as those represented in Figures 6, 7, 8, 9, and 

 10. 



3. Herbivorous Beetles, which feed on Plants and Fruits, as Snout 

 Beetles, or Weevils, Capricorn Beetles, etc. 



The first two families are useful to man, and deserve our 

 protection ; but the last are noxious, and should be de- 

 stroyed wherever encountered. 



The distinguished French Entomologist, Latreille, divided 

 Beetles into five tribes, according to the number of joints 

 found on their feet. Thus he called those that have five 



