278 DARWINISM TO-DAY. 



specialisation, adaptation, that is, towards progressive evo- 

 lution. Other authors who accept such a theory of an inher- 

 ent driving force in organisms speak of this factor variously 

 as an "inner directive force," an "inner law of development/* 

 or an "intrinsic tendency towards progress," etc. Nageli 

 believes that animals and plants would have developed about 

 as they have even had no struggle for existence taken place 

 and the climatic and geologic conditions and changes been 

 quite different from what they actually have been. Kor- 

 schinsky ai says: "In order to explain the origin of higher 

 forms out of lower it Is necessary to assume in the organism 

 a special tendency towards progress." That is, to the be- 

 lievers in this kind of a theory of orthogenesis organic 

 evolution has been and is now ruled by unknown inner 

 forces inherent in organisms, and has been independent of 

 the influence of the outer world. The lines of evolution are 

 immanent, unchangeable, and ever slowly stretch toward 

 some ideal goal. It is needless to say that but few biologists 

 confess to such a belief. However much in the dark we 

 may be regarding the .whole great secret of bionomics, how- 

 ever partial and fragmentary our knowledge of the processes 

 and mechanism of evolution, such an assumption of a mystic, 

 essentially teleologic force wholly independent of and 

 dominating all the physico-chemical forces and influences 

 that we do know and the reactions and behaviour of living 

 matter to these influences which we are beginning to 

 recognise and understand with some clearness and fulness 

 such a surrender of all our hardly won actual scientific 

 knowledgem favour of an unknown, unproved, mystic vital 

 force we are not prepared to make. As Plate well says, such 

 a theory of orthogenesis 12 is opposed, in sharpest contrast, 

 to the very spirit of science. 



On the contrary, the theories of orthogenesis of the 

 general type exemplified by Eimer's 13 are directly in line 

 with the spirit of modern biological methods and investiga- 



