SIR CHARLES LYELL 213 



to those in which scarcely a single species flourished, which we do not 

 know to exist at present. Dr. A. Philippi, indeed, after an elal)orate 

 comparison of the fossil tertiary shells of Sicily with those now living 

 in the Mediterranean, announced, as the result of his examination, that 

 there are strata in that island which attest a very gradual passage 

 from a period when only thirteen in a hundred of the shells were like 

 the species now living in the sea, to an era when the recent species 

 had attained a proportion of ninety-five in a hundred. There is, 

 therefore, evidence, he says, in Sicily of this revolution in the animate 

 world having been effected "without the intervention of any convul- 

 sion or abrupt changes, certain species having from time died out, and 

 others having been introduced, until at length the existing fauna was 

 elaborated." 



In no part of Europe is the absence of all signs of man or his works, 

 in strata of comparatively modern date, more striking than in Sicily. 

 In the central parts of that island we observe a lofty table-land and 

 hills, sometimes rising to the height of 3,000 feet, capped with a lime- 

 stone, in which from 70 to 85 per cent of the fossil testacea are specifi- 

 cally identical with those now inhabiting the Mediterranean. These 

 calcareous and other argillaceous strata of the same age are inter- 

 sected by deep valleys which appear to have been gradually formed by 

 denudation, but have not varied materially in width or depth since 

 Sicily was first colonized by the Greeks. The 'limestone, moreover, 

 which is of so late a date in geological chronology, was quarried for 

 building those ancient temples of Girgenti and Syracuse, of which the 

 ruins carry us back to a remote era in human history. If v/e are lost 

 in conjectures when speculating on the ages required to lift up these 

 formations to the height of several thousand feet above the sea, and 

 to excavate the valleys, how much more remote must be the era when 

 the same rocks were gradually formed beneath the waters ! 



The intense cold of the Glacial period was spoken of in the tenth 

 chapter. Although we have not yet succeeded in detecting proofs of 

 the origin of man antecedently to that epoch, we have yet found evi- 

 dence that most of the testacea, and not a few of the quadrupeds, 

 which preceded, were of the same species as those which followed the 

 extreme cold. To whatever local disturbances this cold may have 

 given rise in the distribution of species, it seems to have done little 

 in effecting their annihilation. We may conclude, therefore, from a 



