68 INTRODUCTION. 



lion upon all those subjects which have hern left for man to investi- 

 gate." If, then, the origin of the human rare, from a single pair, 

 can he proved a< all, it must be proved independently of the Ji 



Scriptures; it must be t • pure scientific question. 



Many i f the varieties of domestic animals arc ascribed to climate. 

 If this be the true cause :. \ I, " why do we find different 



varieties in the same climate 1 Why does the Durham breed <>f 

 cattle continue in the United States with all its peculiarity 

 The care of man, gTeater than the influence of climate, can keep 

 up varieties in spite of it. Superficial observers — "those who 

 have only known the differences called climatic differeno 

 between some mammalia and birds, which occur simultaneously in 

 different latitudes — may well have assumed that such differ 

 have been produced by change introduced in the course of time ;" 

 but when we consider the great mass of facts in natural history, 

 known only to those who have made it a special study, these inade- 

 quate and accidental causes cannot explain si. eh <_'< neral phenomena. 



In considering this subject we are not to confound the Unity of 

 Mankind with the Diversity of Origin of the Human Races — ques- 

 tions which are quite distinct, and have almost no connection with 

 each other. 



The geographical distribution of animals furnishes to the natural- 

 ist very strong evidence in favor of the original diversity of the 

 human races. There are certain recognized zoological and botan- 

 ical provinces, with well-defined and constant limits. The Fauna 

 and Flora of each hemisphere, and of each zone, have their peculiar 

 characters; more resembling each other as we go towards the 

 north, and more widely different as we approach the equator. Even 

 marine animals, in an element undergoing very little change and 

 especially suited for rapid and distant migrations, are restricted to a 

 certain extent of surface, or are confined strictly to certain depths. 

 We have no right to say that the law, " Thus far shalt thou go, and 

 no farther." was impressed on animal and vegetable life as a subse- 

 quent addition to the creative act. 



We know, too, that there have been successive creations of ani- 

 mals and plants at different geological periods : and that they were 

 distributed in localities best suited for their life and growth for a 

 certain time. In many instances, as in the Edentata of Brazil and 

 the Marsupiata of New Holland, these fossil types were the same 

 as the actually existing types of these localities, though of different 

 genera and species ; this coincidence of distinct creations, separated 

 by immense intervals of time, but occupying precisely the same 

 limits, is certainly difficult to explain by the theory of the origin of 



