214 CONTINUITY. 



authentication, that the non-observation of such instances 

 cannot be regarded as absolute disproof of their possible 

 occurrence. 



The more the gaps between species are filled up by the 

 discovery of intermediate varieties the stronger becomes the 

 argument for transmutation and the weaker that for succes- 

 sive creations, because the former view then becomes more 

 and more consistent with experience, the latter more discordant 

 from it. As undoubted cases of variation, more or less per- 

 manent from given characteristics, are produced by the effects 

 of climate, food, domestication, &c., the more species are 

 increased by intercalation, the more the distinctions slide 

 down towards those which are within the limits of such ob- 

 served deviations ; while, on the other hand, to suppose the 

 more and more frequent recurrence of fresh creations out of 

 amorphous matter is a multiplication of miracles or special 

 interventions not in accordance with what we see of the uni- 

 form and gradual progress of nature, either in the organic or 

 inorganic world. If we were entitled to conclude that the 

 progress of discovery would continue in the same course, and 

 that species would become indefinitely multiplied, the distinc- 

 tions would become infinitely minute, and all lines of demar- 

 cation would cease, the polygon would become a circle, the 

 succession of points a line. Certain it is that the more we 

 observe the more we increase the subdivision of species, and 

 consequently the number of the supposed creations ; so that 

 new creations become innumerable ; and yet of these we have 

 no one well-authenticated instance, and in no other observed 

 operation of nature have we seen this want of continuity, these 

 frequent per sallum deviations from uniformity, each of which 

 is a miracle. 



The difficulty of producing intermediate offspring from 

 what are termed distinct species and the infecundity in many 

 instances of hybrids are used as strong arguments against 

 continuity of succession ; on the other hand, it may be said 

 long-continued variation through countless generations has 

 given rise to such differences of physical character that repro- 

 duction is difficult in some cases, and. in others impossible. 



Suppose, for instance, M to represent a parent race whose 



