DARWINISM ATTACKED. 33 



tions rather than uniformly out in all directions. Also it 



is true, and this has of course been long known, that by 



no means all variations are so slight nor in 



Discontinuous i r ,1 i 



variation, suc " P er i ec tly gradatory or continuous series 



as is true of the gradatory Darwinian variations. 

 "Sports" have been known to breeders of plants and animals 

 ever since plant and animal breeding began. Bateson has 

 filled a large book with records of "discontinuous varia- 

 tions" in animals ; variations, that is, of large size and not 

 occurring as members of continuous gradatory series. So 

 that biologists are acquainted with many cases of variation 

 that seem to be of a kind, or to exhibit a tendency, to in- 

 stitute special directions of development, and thus not to be 

 of the simple, non-initiating, inert character of the fortuitous, 

 slight, fluctuating variations, among which natural selection 

 is presumed to choose those that are to become the be- 

 ginnings of new lines of modification and descent. Many 

 biologists believe firmly that variations occur in many 

 special cases, if not in most cases, only along certain special 

 lines. Palaeontologists believe, practically as a united body, 

 that variation has followed fixed lines through the ages ; 

 that there has been no such unrestricted and utterly free play 

 of variational vagary as the Darwinian natural selection 

 theory presupposes. 



Now it is at least obvious that natural selection is abso- 

 lutely limited in its work to the material furnished by varia- 

 tion ; so that if variation occurs in any cases 

 Determinate on ty along certain determinate lines selection 

 variation as a can ^0 no more than make use of these lines. 



species-forming 



factor. Indeed if variation can occur persistently along 



determinate lines natural selection's function in 

 controlling evolution in such cases is limited to the police 

 power of restricting or inhibiting further development along 

 any one or more of these lines which are of a disadvan- 

 tageous character, that is, a character which handicaps or 



