116 STATE OF DEVELOPMENT OF [Chap. XI. 



On the State of Development of Ancient compared with 



Living Forms. 



We have seen in the fourth chapter that the degree 

 of differentiation and specialisation of the parts in 

 organic beings, when arrived at maturity, is the best 

 standard, as yet suggested, of their degree of perfection 

 or highness. We have also seen that, as the speciali- 

 sation of parts is an advantage to each being, so natural 

 selection will tend to render the organisation of each 

 being more specialised and perfect, and in this sense 

 higher ; not but that it may leave many creatures with 

 simple and unimproved structures fitted for simple con- 

 ditions of life, and in some cases will even degrade or 

 simplify the organisation, yet leaving such degraded 

 beings better fitted for their new walks of life. In 

 another and more general manner, new species become 

 superior to their predecessors ; for they have to beat in 

 the struggle for life all the older forms, with which they 

 come into close competition. We may therefore con- 

 clude that if under a nearly similar climate the eocene 

 inhabitants of the world could be put into competition 

 with the existing inhabitants, the former would be beaten 

 and exterminated by the latter, as would the secondary 

 by the eocene, and the palaeozoic by the secondary 

 forms. So that by this fundamental test of victory in 

 the battle for life, as well as by the standard of the 

 specialisation of organs, modern forms ought, on the 

 theory of natural selection, to stand higher than ancient 

 forms. Is this the case ? A large majority of palaeon- 

 tologists would answer in the affirmative ; and it seems 

 that tins answer must be admitted as true, though 

 difficult of proof. 



