142 PRIMITIVE ANIMALS 



of exact science to correct the inexact speculations of 

 biology, as to the age of the earth and the duration of 

 life upon it, have ended in conceding to the biologist 

 almost unlimited time for the accomplishment of the 

 changes which he must believe to have occurred. We 

 cannot readily explain the persistence of certain or- 

 ganic types unchanged through such untold ages; the 

 reason may be found in the relation of the organism 

 to its environment or in the untractable nature of 

 the organism itself, which may in some way have lost 

 the power of further variation and the acquisition of 

 new capacities, but if the final congelation of the 

 globe should discover the human race with the same 

 average physical structure, and the same mental and 

 moral capacity, as at the present time, the apostle of 

 progress might sigh, but the philosopher would not 

 hesitate, to record another example of a persistent 

 type. 



The progress, decay or stagnation of humanity 

 may divert the speculations of a philosopher or 

 engage the concern of a statesman ; man will con- 

 tinue to spread over the earth ; and a zoologist 

 must enquire into the probable fate of those inferior 

 creatures whom it is his especial province to study. 



The primaeval savage, before he had acquired the 

 rudimentary arts of civilization, maintained a dubious 

 existence among the wild animals and in scenes of 

 untamed vegetation, over which he exercised but 



