160 Coleoptera of the Eastern 



auratus has been carried in the earth surrounding the roots of trees. 

 So varied, in truth, is the habitation of the insect world, that almost 

 every conceivable importation may serve as the nidus of some spe- 

 cies, which radiating from this point may, in the course of time, 

 become completely naturalized in a foreign land. 



There are, however, other kinds for whose presence in this 

 country no such satisfactory reason can be assigned. They are not 

 confined to the more settled portions of our republic, nor is their 

 occurrence a matter of such rarity as to render it probable that their 

 abode on this continent has been of short duration. It is to these 

 mainly that we shall confine our attention. 



It is not intended in this essay to enter into a detailed examina- 

 tion of the various theories which have been proposed, in order to 

 account for these coincidences of production : any generalizations 

 from the few facts at present possessed on the subject, would be al- 

 together premature. Patient investigation must first make known 

 the limits, of the distribution of these animals, and then we may hope 

 to evolve a theory suitable to the results obtained. 



Any such reputed fact, as the discovery of a species on this con- 

 tinent, which has heretofore been supposed to be confined to the 

 old world, should be received with extreme hesitation, and admit 

 ted as correct only after the most rigid examination. Many such 

 pretended discoveries have been overthrown by the increase of our 

 knowledjr ■ ; similar assertions should therefore be submitted to 

 the strictest scrutiny. 



Entering for a short time into the regions of speculation, we 

 might, easily suppose a priori, that in the operation of the general 

 laws of creation, which probably obtain throughout the physical uni- 

 verse, the productions of the two hemispheres would approximate 

 in character, according as the circumstances under which they ori- 

 ginated were more or less similar. Now one of the most efficient 

 of these circumstances, because one that always continues acting 

 with equal force, is a similarity of climate. It is also a fact, almost 

 self-evident indeed, from physical considerations, that the climates of 

 the two continents approach more nearly to each other, the farther 

 we proceed north ; it might therefore be inferred that the similari- 



