jo6 THE POPULAR SCIENCE MONTHLY. 



nally, and lias always been, peopled by migrations from the Old 

 World. At the risk of repeating myself, I will briefly sum up the 

 grounds of my conviction. 



Permit me first to recall the two rules which I have constantly 

 followed in the solution of the questions, sometimes so ardently 

 contested, which the history of man raises. The first is to put 

 away absolutely every consideration borrowed from dogma or 

 philosophy, and to invoke only science that is, experiment and 

 observation. The second is, never to isolate man from other 

 organized beings ; and to admit that he is subject, as to all that 

 is not exclusively human, to all the general laws which control 

 equally animals and plants. Hence, we can not regard as true 

 any doctrine or opinion which makes man an exception among 

 organized beings. 



We make the application of these principles to the question 

 which occupies us, but in a broader way ; for it is only a special 

 case of a more general problem which we may formulate in the 

 terms Man is everywhere now : did he appear everywhere in the 

 beginning ? If not absolutely cosmopolitan in its origin, did the 

 race appear at an indefinite number of points ? Or, rather, born at 

 a single and limited spot, has it gradually taken possession of the 

 whole earth by migration ? At first thought we might suppose 

 that the answer to these questions would be very different accord- 

 ing as we admit the existence of one or many human species. 

 That would be a mistake. We purpose to show that polygenists 

 can shake hands with monogenists on this point, without involv- 

 ing themselves in any contradiction. We take, first, the mono- 

 genist view. 



Physiology, which leads us to recognize the unity of the hu- 

 man race, teaches us nothing in reference to its primary geo- 

 graphical origin. It is otherwise with the science which concerns 

 the distribution of animals and plants over the surface of the 

 globe. The geography of organic beings has also its general 

 facts, which we call laws. These facts these laws must be 

 learned and interrogated in order to solve the problem of the 

 manner in which the globe was peopled. The first result of this 

 inquiry is a demonstration that real cosmopolitanism, as we at- 

 tribute it to man, does not exist anywhere, either in the animal 

 or the vegetable kingdom. I cite a few of the evidences in sup- 

 port of this affirmation. 



Take, first, what De Candolle says, that " no phanerogamous 

 plant extends over the whole surface of the earth. There hardly 

 exist more than eighteen the areas of which reach over half the 

 lands ; and there is no tree or shrub among the plants of most 

 considerable extension/' The last remark touches an order of 

 considerations on which I shall insist further on. 



