Ixxii KEFOKT — 1866. 



Geologicfil discoveries seemed, in the early period of the science, to show 

 complete extinction of certain species and the appearance of new ones, great 

 gaps existing between the characteristics of tlic extinct and the new species. 

 As science advanced, these were more or less filled np ; the apparent dif- 

 ficulty of admitting nnhmitcd modification of species would seem to have 

 arisen from the comparison of the extreme ends of the scale where the inter- 

 mediate links or some of them were wanting. 



To suppose a Zoophyte the progenitor of a Mammal, or to suppose at some 

 particular period of time a highly developed animal to have come out of 

 nothuig, or suddenly grown out of inorganic matter, would appear at first 

 sight equally extravagant hypotheses. As an efi'ort of Almighty creative 

 power, neither of these alternatives presents more difiiculty than the other ; 

 but as we have no means of ascertaining how creative power worked, but by 

 an examination and studj- of the works themselves, we are not lilcely to get 

 cither side proved to ocular demonstration. A single phase in the progress 

 of natural transmutation would probably require a term far transcending all 

 that embraced by historical records ; and on the other hand, it niiglit be said, 

 sudden creations, though taking place frequently, if viewed with reference to 

 the immensity of time involved in geological pei-iods, may be so rare v.'ith 

 reference to our experience, and so difficult of clear 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 discoveiy of inter- 

 mediate varieties, the stronger becomes the argument for transmutation and 

 the weaker that for successive creations, because tlie former view then 

 becomes more and more consistent with experience, the latter more discor- 

 dant from it. As undoubted cases of variation, more or less permanent, from 

 given characteristics, are produced by the effects of climate, food, domestica- 

 tion, (fcc, the more species are increased by intercalation, the more the di- 

 stinctions slide down towards those which are within the limits of such 

 observed deviations ; while on the other hand, to suppose the more and more 

 frequent recurrence of fresh creations oiit of amorphous matter, is a multipli- 

 cation of miracles or special interventions not in accordance with what we 

 see of the uniform and gradual progress of nature, either in the organic or 

 inorganic world. If we were entitled to conclude that the progress of dis- 

 covery would continue in the same course, and that species would become 

 indefinitely multiplied, the distinctions woidd become infinitely minute, and 

 all lines of demarcation Avould 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 these 

 supposed creations; so that new creations become innumerable, and yet of these 

 we have no one well- authenticated instance, and in no other observed opera- 

 tion of nature have we seen this want of continuity, these frequent ^cr salium 

 deviations from uniformity, each of which is a miracle. 



The difficiilty of producing intermediate offspring from what arc 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 reproduction is difiicult in 

 some cases and in others impossible. 



Suppose, for instance, M to represent a parent-race whose offspring by 

 successive changes through cons of time have divaricated, and produced on 

 the one hand a species A, and on the other a species Z, the changes here have 

 been so great that we should never expect directly to reproduce an interme- 



