AND THE THEORY OF DEVELOPMENT. l6j 



admitted on all hands. The general principle of natural 

 selection will account for this in the rough, maintaining 

 as it does that fresh varieties, species, and genera better 

 adapted to the surrounding circumstances have arisen., 

 and by their superior adaptation unavoidably ousted the 

 older forms. Digging down into the records of history 

 we find a time when the Romans were supreme in the 

 civilized world ; no two consecutive years of the interval 

 present any remarkable divergence of the prevailing 

 conditions, yet now we may say of that Roman supremacy 

 in the civilized world, that, ' like the Mastodon, it is a 

 thing of the past.' 



Torquay, May 14, 1870. 



