^^"^ THE NEW EVOLUTION "^""^ 



which intermediate states, if they are chemical and 

 physical possibilities, are positions of instability. 



Precisely the same phenomenon occurs among ani- 

 mals in which, however, it is usually overlooked or 

 misinterpreted. One scarcely expects an animal to 

 be partly one thing and partly another. This con- 

 dition is most obvious and most easily demonstrated 

 in the feather-stars (fig. 43, p. 87) and sea-lilies (fig. 

 6, p. 5) in which sometimes one or even two of the 

 five rays will be replaced by rays of a type belonging 

 to a widely different species. Several such cases 

 have been described. 



The more we study species the more clearly do we 

 see that a species is a fluid unit, held to its present 

 form by forces which it cannot overcome. The 

 ability to expand and to produce new forms is inherent 

 in almost every species at the present time; but the 

 opportunity is lacking. 



[148] 



