No. 637] 



ADAPTATIOh' 



361 



''tends by its very nature to a higher organization."-' 

 The botanist Naegeli is one of the best known exponents 

 of such a* view. With some, like St. George IMivart, the 

 question has been closely interwoven with special theo- 

 logical beliefs. 



This writer believed in an "innate tendency to deviate 

 at certain times and under certain conditions," which 

 tendency he held to be "an harmonious one, calculated to 

 simultaneously adjust the various parts of the organism 

 to their new relations." And this guiding hand seems 

 to have been exercised not only in the direction of satis- 

 fying the needs of the organism itself, but in adapting 

 the latter to the needs of man. Speaking of the evolu- 

 tion of the horse, he tells us : 



be allowed to consider that one motive of this modification (among 



Others, like Wallace, have had recoiifsc to such a guid- 

 ing principle only in accounting for tiie origin of man. 



In recent years, the philosopher Bergson lias adopted 

 a vitalistic theory of evolution, weaving it into a meta- 

 physical system of which an important feature is the 

 essentially creative character of time or "duration." 

 We see the world of living things moving grandly on 

 through the ages, impelled by a mysterious force, the 

 "elan vital," and flowering out spontaneously into a 

 never-ending succession of living wonders. Such a con- 

 ception may stir the imagination, but it does not add to 

 our knowledge. 



Now, curiously enough, this "teleological" factor has 

 been introduced by various writers to explain two exactly 

 opposite classes of cases: (1) tlie origin of adaptive char- 



