CHAP, xvii THE EVIDENCES OF EVOLUTION 339 



by the activity of its inherent principles, rather than by a 

 sudden evolution of the whole by the Almighty fiat." 

 In short, we have extended to the world around us 

 man's characteristic conception of human history. The 

 evolution idea means that the present is the child of the 

 past and the parent of the future. " As in the develop- 

 ment of a fugue," Samuel Butler says, " where, when 

 the subject and counter-subject have been announced, 

 there must thenceforth be nothing new, and yet all must 

 be new, so throughout organic nature which is a fugue 

 developed to great length from a very simple subject 

 everything is linked on to and grows out of that which 

 comes next to it in order errors and omissions excepted." 

 When an egg by a series of changes becomes a chick, 

 we speak of development. It is one organism throughout, 

 though no one unaware of the facts could have predicted 

 the end from the beginning. An implicit organisation 

 becomes explicit in a very wonderful way. Somewhat 

 in the same way we should speak of the development 

 of the solar system, and the development of our earth. 

 For if we call this evolution we are apt to forget that in 

 organic evolution there is the continual elimination of the 



e? 



unsuccessful. The result at any given time represents 

 only a very small fraction of the antecedents that led up 

 to it. In fact, the term evolution is best kept for the 

 realm of organisms. 



2. Arguments for Evolution. What then are the facts 

 which have convinced naturalists that the plants and the 

 animals of to-day are descended from others of a simpler 

 sort, and the latter from yet simpler ancestors, and so on, 

 back and back to those first forms in which all that suc- 

 ceeded were implied ? The best answer is in Darwin's 

 Origin of Species, where the arguments were marshalled 

 in such a masterly fashion that they won the conviction 

 of the world. Darwin's arguments were derived (a) from 

 the distribution of animals in space ; (b) from their suc- 

 cessive appearance in time ; (c) from actual variations 

 observed in domestication, cultivation, and in nature ; 

 (d) from facts of structure, e.g. homologous and rudi- 

 mentary organs ; (e) from embryology. We shall simply 



