CHAPTER XXIX. 



THEORY OF EVOLUTION. 



In Chapter VI. we indicated the nature of the evidence 

 which has led naturalists all but unanimously to accept the 

 doctrine of descent as a modal interpretation of organic 

 nature. The data of physiology and morphology, combined 

 with what is known of the history of the race and the 

 development of the individual, have led us to believe that 

 the forms of life now around us are descended from 

 simpler ancestors (except in cases of degeneration), and 

 these from still simpler, and so on, back to the mist of life's 

 beginnings. In other words, we believe that the present is 

 the child of the past and the parent of the future. This is 

 the general idea of evolution. 



But while this general idea, which is a very grand one, is 

 usually recognised as the simplest interpretation of the 

 facts, we remain in doubt as to ihe factors of the process by 

 which the world of life has come to be what it is. This 

 uncertainty is in part due to the complexity of the problem, 

 in part to the relative novelty of the inquiry — for precise 

 etiology is not yet fifty years old, in part also to the fact 

 that while there has been much theorising, there has been 

 comparatively little experimenting or connected obser- 

 vation as to the modes and causes of evolution. 



With the exception of Alfred Russel Wallace and a few 

 others who believe that it is necessary to postulate spiritual 

 influxes to account for certain obscure beginnings, e.g., of 

 the higher human qualities, evolutionists are agreed in 

 seeking to explain the evolution of plants and animals as a 

 continuous " natural " process, the end of which was 



