312 CONCLUSION 



was in the main influenced by the facts known concerning " per- 

 sistent types," among the lower forms of life, existing in geological 

 strata from the Cambrian and Silurian periods onwards. He, 

 indeed, distinctly intimates that the longer the persistence through 

 geologic ages of any given type of life the greater would have been 

 the time needful for its origination/ 



What I have already said concerning " persistent types," how- 

 ever, will have shown that a totally different interpretation may be 

 put upon such facts, when once the doctrine of heterogeresis is 

 admitted. It certainly would no longer be needful to assume, with 

 Darwin and with Poulton, that the rate of change is slow among 

 low as compared with higher forms of life. Such a conclusion is 

 directly opposed to a large mass of other evidence, and is, I believe, 

 absolutely the reverse of the truth. 



Such a view is, moreover, far from being shared by other eminent 

 biologists. Thus Adam Sedgwick, in his address to the Zoological 

 Section of the British Association in 1899, said that the facts of 

 palaeontology when closely scrutinised lend support to the view 

 that " variation was much greater near the dawn of life than it is 

 now, and heredity a correspondingly less important phenomenon " ; 

 while Prof. Hickson on a similar occasion in 1903 gave expression 

 to very similar views. He went even so far as to say, " that in 

 the earliest stages of evolution the condition of extreme plasticity 

 and ready response to changing external conditions were necessary 

 for the survival of the species." Several interesting facts and 

 quotations, in the same direction, are also cited by Sir Edward Fry 

 in the before-mentioned article,^ while Charles A. White calls 

 attention to many other important palaeontological facts having a 

 like significance.3 



Thus, if instead of believing with Darwin that " all the living 

 forms of life are the lineal descendants of those that lived long 

 before the Cambrian epoch," and that " all the organic beings 

 which have ever lived on this earth may be descended from some 

 one primordial form," it should be admitted that life originally 

 started from multitudes of centres (as the uniformity of natural 

 phenomena would demand) ; that from the earliest stages of the 

 earth's history up to the present time new starting points of 

 simplest forms have been ever taking place all over the surface 



' Loc. cit., p, 509. 



" " The Monthly Review," January, 1903, p. 81. 



3 " The Smithsonian Report," 1901, p. 638. 



