278 ON THE ORIGIN OF SPECIES 



world, for instance in South America, of bare meta- 

 morphic rocks, which must have been heated under 

 great pressure, have always seemed to me to require 

 some special explanation ; and we may perhaps believe 

 that we see in these large areas, the many formations 

 long anterior to the silurian epoch in a completely 

 metamorphosed condition. 



The several difficulties here discussed, namely our 

 not finding in the successive formations infinitely 

 numerous transitional links between the many species 

 which now exist or have existed ; the sudden manner 

 in which whole groups of species appear in our European 

 formations ; the almost entire absence, as at present 

 known, of fossiliferous formations beneath the Silurian 

 strata, are all undoubtedly of the gravest nature. We 

 see this in the plainest manner by the fact that all the 

 most eminent palaeontologists, namely Cuvier, Agassiz, 

 Barrande, Falconer, E. Forbes, etc., and all our greatest 

 geologists, as Lyell, Murchison, Sedgwick, etc., have 

 unanimously, often vehemently, maintained the im- 

 mutability of species. But I have reason to believe 

 that one great authority, Sir Charles Lyell, from further 

 reflection entertains grave doubts on this subject. I 

 feel how rash it is to differ from these authorities, to 

 whom, with others, we owe all our knowledge. Those 

 who think the natural geological record in any degree 

 perfect, and who do not attach much weight to the 

 facts and arguments of other kinds given in this 

 volume, will undoubtedly at once reject my theory. 

 For my part, following out Lyell's metaphor, I look at 

 the natural geological record, as a history of the world 

 imperfectly kept, and written in a changing dialect ; 

 of this history we possess the last volume alone, relat- 

 ing only to two or three countries. Of this volume, 

 only here and there a short chapter has been preserved ; 

 and of each page, only here and there a few lines. 

 Each word of the slowly-changing language, in which 

 the history is supposed to be written, being more or 

 les* different in the interrupted succession of chapters, 



