58 ESSAY ON CLASSIFICATION. 



the conviction, that neither animals nor plants could 

 have originated upon one and the same spot upon the 

 surface of the earth, and thence have spread more and 

 more widely until the whole globe became inhabited. It 

 was indeed an immense progress which freed science 

 from the fetters of an old prejudice. For now that we 

 have the facts of the case before us, it is difficult to con- 

 ceive how, by assuming such a gradual dissemination 

 from one spot, the diversity which exists in every part of 

 the globe could ever have seemed to be explained. But, 

 even to grant distinct centres of distribution for each 

 species, within, their natural boundaries, is only to meet 

 the facts half way, as there are innumerable relations be- 

 tween the animals and plants found everywhere associ- 

 ated together, which must be considered as primitive, 

 and cannot be the result of successive adaptation. And if 

 this be so, it would follow that all animals and plants 

 have occupied, from the beginning, those natural boun- 

 daries within which they stand one to another in such 

 harmonious relations. 1 Pines have originated in forests, 

 heaths in heaths, grasses in prairies, bees in hives, her- 

 rings in shoals, buffaloes in herds, men in nations. 2 I see 

 a striking proof that this must have been the case in the 

 circumstance, that representative species, which, as dis- 

 tinct species, must have had from the beginning a dif- 

 ferent and distinct geographical range, frequently occupy 

 sections of an area simultaneously inhabited by the re- 

 presentatives of other species, which are perfectly iden- 

 tical over the whole area. By way of an example, I 

 would mention the European and the American Widgeon, 



1 AGASSIZ (L.), Geographical Dis- 3 AGASSIZ (L.), The Diversity of 

 tribution of Animals, Christian Ex- Origin of the Human Races, Chris- 

 ainmer; Boston, 1850, 8vo. (March.) tiaii Examiner; Boston, 1850, 8vo. 



