APPARITION OF SPECIES 105 



was taken from them, were continued in lower posi 

 tions under the new dynasties. Thus none of the 

 lower types of life introduced was finally abandoned, 

 but, after culminating in the highest forms of which 

 it was capable, each was still continued, though with 

 fewer species and a lower place. Examples of this 

 abound in the history of all the leading groups of 

 animals and plants. 



4. There is thus a continued plan and order in 

 the history of life, which cannot be fortuitous, and 

 which is coincident with the gradual perfection of the 

 physical conditions of the earth itself. The chance 

 interaction of organisms and their environment, even 

 if we assume the organisms and environment as given 

 to us, could never produce an orderly continuous pro 

 gress of the utmost complexity in its detail, and ex 

 tending through an enormous lapse of time. It has 

 been well said that if a pair of dice were to turr up 

 aces a hundred times in succession, any reasonable 

 spectator would conclude that they were loaded dice ; 

 so if countless millions of atoms and thousands of 

 species, each including within itself most complex 

 arrangements of parts, turn up in geological time in 

 perfectly regular order and a continued gradation of 

 progress, something more than chance must be im 

 plied. It is to be observed here that every species 

 of animal or plant, of however low grade, consists ofl 

 many co-ordinated parts in a condition of the nicest 

 equilibrium. Any change occurring which produces 



