380 THE CONCEPT OF EVOLUTION 



mutations seem to be important realities. What is meant by the con- 

 tinuity of evolution is that each stage in the process has its full pre- 

 condition (we do not say interpretation) in what precedes. There 

 is a flesh-and-blood continuity of lineage (' enchainement des etres '), 

 and there is also continuity in the extra-organismal order which 

 includes the established system of inter-relations. 



In regard to the progressiveness of Animate Evolution, three ad- 

 missions must first be made. There have been many retrogressive 

 lines, notably in adaptation to parasitism and sedentary life. There 

 are also many corners where organisms seem to have run riot in 

 exuberant complication, often extraordinarily beautiful, but with- 

 out further significance that we can discern. Some of the most 

 striking achievements of evolution, such as the flying dragons, have 

 passed away in their prime without leaving direct descendants. It 

 is probable, however, that the distinctive gains of these lost racn 

 may have been conserved on collateral lines. 



These admissions notwithstanding, the large fact is certain that 

 on the whole there has been progressive differentiation and in- 

 tegration along diverse lines, an increase in the complexity and 

 masterfulness of behaviour, a growing emancipation of mind, and 

 an approximation to personality. This is the fundamental fact to 

 be borne in mind in our interpretation of evolution. 



