CHAP. X.] IN LOWEST FOSSILIFEROUS STRATA. 271 



continents may have existed where oceans are now spread out ; 

 and clear and open oceans may have existed where our continents 

 now stand. Nor should we be justified in assuming that if, for 

 instance, the bed of the Pacific Ocean were now converted into 

 a continent 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 miles nearer to the centre of 

 the earth, and which had been pressed on by an enormous weight 

 of superincumbent water, might have undergone far more meta- 

 morphic 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 palaeon- 

 tologists, namely, Cuvier, Agassiz, Barrande, Pictet, Falconer, E. 

 Forbes, <fec., and all our greatest geologists, as Lyell, Murchison, 

 Sedgwick, &c., have unanimously, often vehemently, maintained 

 the immutability 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 lines. 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 have 

 been abruptly introduced. On this view, the difficulties above 

 discussed are greatly diminished, or even disappear. 



