GEOGRAPHY OF THE PETALOCERA. 43 



an arrangement and application of such facts to the dis- 

 covery of the general limits by which the dispersion of 

 insects over the earth is restricted. This imperfection, if 

 it be one, is however to be attributed solely to the almost 

 insuperable obstacles which impeded his researches. 



Insects are, it need hardly be said, a despised set of 

 beings; though, were we not accustomed to judge of them 

 by their individual size, and were we to look at their num- 

 bers and effects, they would assuredly be found among the 

 most powerful agents which nature employs in maintaining 

 the equilibrium of the animal kingdom. The joint conse- 

 quence, however, of the neglect which they have suffered 

 and of their numberless swarms is, that, compared with the 

 whole number of species, we are acquainted with but few. 

 Well then may Latreille say that the imperfect state of 

 our catalogues has prevented him from pursuing any 

 other plan than that which he has adopted. 



Having, however, had the good fortune to inspect al- 

 most every collection of note in Europe, excepting those 

 of Vienna and Berlin, I conceive myself in possession of 

 data sufficient to justify an attempt to combat the diffi- 

 culty under which M. Latreille laboured, and to offer to 

 entomologists the following rough estimate of the various 

 geographical proportions in which the families of Petalo- 

 cera occur. It would, nevertheless, be highly improper not 

 to acknowledge that such calculations, after all, are but 

 vague approximations to the truth, which have nothing to 

 support their accuracy, but inferences drawn from the 

 inspection of many and extensive entomological collec- 

 tions. As such then I give them. 



The leading principles upon which organized beings 

 appear to have been dispersed over the globe, are few and 



