320 DARWINISM STATED BY DARWIN HIMSELF. 



process of natural selection will have been supplanted 

 and exterminated, so that they will no longer be found 

 in a living state. 



Thirdly, when two or more varieties have been formed 

 in different portions of a strictly continuous area, inter- 

 mediate varieties will, it is probable, at first have been 

 formed in the intermediate zones, but they will generally 

 have had a short duration. For these intermediate va- 

 rieties will, from reasons already assigned (namely, from 

 what we know of the actual distribution of closely-allied 

 or representative species, and likewise of acknowledged 

 varieties), exist in the intermediate zones in lesser num- 

 bers than the varieties which they tend to connect. From 

 this cause alone the intermediate varieties will be liable 

 to accidental extermination ; and, during the process of 

 further modification through natural selection, they will 

 almost certainly be beaten and supplanted by the forms 

 which they connect ; for these from existing in greater 

 numbers will, in the aggregate, present more varieties 

 and thus be further improved through natural selection 

 and gain further advantages. 



Lastly, looking not to any one time, but to all time, 

 if my theory be true, numberless intermediate varieties, 

 linking closely together all the species of the same group, 

 must assuredly have existed ; but the very process of 

 natural selection constantly tends, as has been so often 

 remarked, to exterminate the parent-forms and the inter- 

 mediate links. Consequently evidence of their former 

 existence could be found only among fossil remains, which 

 are preserved, as we shall attempt to show in a future 

 chapter, in an extremely imperfect and intermittent 

 record. 



