302 TROPICAL NATURE, AND OTHER ESSAYS. 



If the views now advanced are correct, many, 

 perhaps most, of our existing savages are the successors 

 of higher races ; and their arts, often showing a wonder- 

 ful similarity in distant continents, may have been 

 derived from a common source among more civilised 

 peoples. 



Conclusion. — I must now conclude this very imperfect 

 sketch of a few of the offshoots from the great tree of 

 Biological study. It will, perhaps, be thought by some 

 that my remarks have tended to the depreciation of our 

 science, by hinting at imperfections in our knowledge 

 and errors in our theories where more enthusiastic students 

 see nothing but established truths. But I trust that I 

 may have conveyed to many of my hearers a different 

 impression. I have endeavoured to show that, even in 

 what are usually considered the more trivial and super- 

 ficial characters presented by natural objects, a whole 

 field of new inquiry is opened up to us by the study of 

 distribution and local conditions. And as regards man, 

 I have endeavoured to fix your attention on a class of 

 facts which indicate that the course of his development 

 has been far less direct and simple than has hitherto 

 been supposed ; and that, instead of resembling a single 

 tide with its advancing and receding ripples, it must 

 rather be compared to the progress from neap to spring 

 tides, both the rise and the depression being comparatively 

 greater as the waters of true civilisation slowly advance 

 towards the highest level they can reach. 



And if we are thus led to believe that our present 

 knowledge of nature is somewhat less complete than we 

 have been accustomed to consider it, this is only what 



