ENVIR ONMENT, 



15 



forms of life constituted a scale of ascent from the 

 polyps to man, had been revived in different as- 

 pects, such as the ' perfection chain ' of Leibnitz, 

 or the famous 'echelle' of Bonnet. It is evident 

 that the modern conception grew out of the dis- 

 covery of the extinction of earlier and intermediate 

 forms of life such as came from Paleontology, and 

 that it is essentially different from the ancient 

 ' ladder ' or ' chain ' conception, which regarded the 

 existing terminal twigs of the tree as directly affili- 

 ated to each other, rather than through the extinct 

 earlier branches. Pre-Lamarckian Evolution was 

 mainly a conception of the gradual rise of higher 

 forms of life by descent and modification from 

 lower forms still existing. This, in contrast with 

 the notions of sudden production of life from the 

 earth or by Special Creation, was based upon slow 

 development, and had the distinction always of 

 being a naturalistic explanation. 



The variety of terms under which Evolution has 

 figured, to a certain extent mark the chapters in 

 its history. In France, the early terms ' traiismuta- 

 tion ' and 'filiation ' have partly given way to the 

 more modern ' transformisme' In England, Evo- 

 lution has been known as the ' doctrine of deriva- 

 tion,' as the 'development hypothesis,' and as the 

 'descent theory.' For the first half of this century, 

 Evolution was known mainly as the Lamarckian 

 theory, just as later it universally became the Dar- 

 winian theory ; while very recently ' Lamarckism ' 



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