308 THE POPULAR SCIENCE MONTHLY. 



evident that the area of the actual habitat of any animal or vege- 

 table species includes the center where that species first appeared. 

 By virtue of the law of expansion, the center should likewise be 

 less in extent than the actual area. No plant and no anirnal, there- 

 fore, originated in all the regions of the globe. To suppose that 

 man appeared in the beginning everywhere that we now see him 

 would be to make a unique exception of him. The hypothesis can 

 not, therefore, be received ; and every monogenist must repel the 

 conception of the initial cosmopolitism of the human species as 

 false. 



The same conclusion is imposed on polygenists, unless they 

 refuse to apply to man the laws of botanical and zoological ge- 

 ography that govern all other beings. In fact, however much 

 they have multiplied species of man whether they assume that 

 there are two, with Virey ; fifteen, with Bery Saint-Vincent; or an 

 undetermined but considerable number, with Gliddon they have 

 always united them into a single genus. A human genus can 

 be no more cosmopolitan than a human species. Speaking of 

 plants, De Candolle says, " The same causes have borne on genera 

 and on species " ; and this is as true of animals as of plants. 

 Limiting ourselves to the animals among the cetaceans, Mur- 

 ray thinks that the genera of the rorqual and the dolphin are 

 represented in all the seas ; Van Beneden and Gervais dispute 

 this ; we will, however, admit it, for it will not weaken our conclu- 

 sions. Besides the cetaceans, there can be no question of generic 

 cosmopolitism. Of the ruminants, the genera of the deer, the 

 ox, etc. ; of the carnivores, the cat, dog, bear, etc., have repre- 

 sentatives in both worlds, but not in Australia or Polynesia. 

 Further, as we examine the higher and higher groups, we see 

 the number of these genera of large area diminishing. Finally, 

 not a single genus of monkey is known to be common to the old 

 and the new continents ; and the simian type itself is wanting in 

 the greater part of both worlds and Oceania. 



Thus, whether we regard species or genera, the area of the 

 habitat is the more restricted as the animals are more highly 

 placed in the zoological scale. It is the same with plants. De 

 Candolle says on this point, " The mean area of species is as 

 much smaller as the class to which they belong has a more com- 

 plete, more developed, or, in other words, more perfect organi- 

 zation." 



Progressive cantonment, in proportion to the increasing per- 

 fection of the organisms, is then a general fact, a law, which is 

 applicable to all organized beings, and which physiology easily 

 accounts for. Now, this law disagrees absolutely with the hy- 

 pothesis that there can exist a human race, comprehending sev- 

 eral distinct species, which have appeared everywhere that we see 



