Chap. X.J IMPERFECTION OF GEOLOGICAL RECORD. 289 



we should there find sedimentary formations in a recognisable 

 condition older than the Cambrian strata, supposing such to have 

 been formerly deposited ; for it might well happen that strata 

 which had subsided some mile3 nearer to the centre of the earth, 

 and which had been pressed on by an enormous weight of superin- 

 cumbent water, might have undergone far more metamorphic action 

 than strata which have always remained nearer to the surface. 

 The immense areas in some parts of the world, for instance in 

 South America, of naked metamorphic 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 

 Cambrian epoch in a completely metamorphosed and denuded 

 condition. 



The several difficulties here discussed, namely — that, though we 

 find in our geological formations many links between the species 

 which now exist and which formerly existed, we do not find 

 infinitely numerous fine transitional forms closely joining them all 

 together ; — the sudden manner in which several groups of species 

 first appear in our European formations ; — the almost entire absence, 

 as at present known, of formations rich in fossils beneath the 

 Cambrian strata, — are all undoubtedly of the most serious nature. 

 We see this in the fact that the most eminent palaeontologists, 

 namely, Cuvier, Agassiz, Barrande, Pictet, Falconer, E. Forbes, &c, 

 and all our greatest geologists, as Lyell, Murchison, Sedgwick, 

 &c, have unanimously, often vehemently, maintained the immu- 

 tability of species. But Sir Charles Lyell now gives the support of 

 his high authority to the opposite side ; and most geologists and 

 palaeontologists are much shaken in their former belief. Those 

 who believe that the geological record is in any degree perfect, will 

 undoubtedly at once reject the theory. For my part, following out 

 Lyell's metaphor, I look at the 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, relating 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 fines. Each word of the slowly-changing language, more or 

 less different in the successive chapters, may represent the forms of 

 life, which are entombed in our consecutive formations, and which 

 falsely appear to us to have been abruptly introduced. On this 

 view, the difficulties above discussed are greatly diminished, or even 

 disappear. 



