394 ORIGIN OF SPECIES 



The inhabitants of the world at each successive period in 

 its histor> have beaten their predecessors in the race for 

 life, and are, in so far, higher in the scale, and their struc- 

 ture has generally become more specialised; and this may 

 account foi the common belief lield by so many palaeontolo- 

 gists, that organisation on the whole has progressed. Extinct 

 and ancient animals resemble to a certain extent the embryos 

 of the more recent animals belonging to the same classes, 

 and this wonderful fact receives a simple explanation accord- 

 ing to our views. The succession of the same types of 

 structure within the same areas during the later geological 

 periods ceases to be mysterious, and is intelligible on the 

 principle of inheritance. 



If then the geological record be as imperfect as many be- 

 lieve, and it may at least be asserted that the record cannot 

 be proved to be much more perfect, the main objections to 

 the theory of natural selection are greatly diminished or dis- 

 appear. On the other hand, all the chief laws of palaeontology 

 plainly proclaim, as it seems to me, that species have been 

 produced by ordinary generation : old forms having been sup- 

 planted by new and improved forms of life, the products of 

 Variation and the Survival of the Fittest. 



