B. THE THEORY OF DESCENT 



1. GENERALITIES 



IT is most generally conceded at the present time that 

 the actually existing state of all organisms whatsoever is 

 the result of their history. What does that mean ? What 

 are the foundations upon which the assumption rests ? 

 What is the relation of systematics to history ? In raising 

 such questions and considerations we are treading the 

 ground sacred to the theory of descent. 



I well know that you prefer the name " theory of 

 evolution >! for what I am speaking of : but it may be 

 misleading in various respects. We already know that quite 

 a determinate meaning has been given to the word " evolu- 

 tio ' as applied to individual morphogenesis, " evolutio " 

 being here opposed to " epigenesis." Now there would be 

 nothing against the use of the word evolution in a wider 

 sense indeed it is often applied nowadays to denote 

 the fact that a something is actually " evolved " in 

 embryology if only our entelechy had taken the place of 

 the machine of the mechanists. But that is the very 

 point : there must be a real " evolving ' of a something, 

 in order that the word evolution may be justified verbally : 

 and that is not the case in so-called phylogeny. At least 



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