THE ORIGIN OF SPECIES 539 



apparently sudden appearance of groups of allied, and by no means 

 absolutely primordial, species in the lowest fossiliferous strata then 

 known. Thirdly, there was the sudden disappearance of whole groups 

 of species at the end of certain geological periods, and their sudden 

 replacement in the next period by species different in type from the 

 former, and closely allied to one another. These two points — the second 

 and third — were the especial contribution of the Cuvierian school to the 

 controversy. Out of Cuvier's doctrine of the abrupt extinction of 

 faunas at the successive " revolutions of the globe," his disciples had 

 elaborated the theory of the radical and world-wide discontinuity of the 

 faunas and floras of the successive great periods, and had hence inferred 

 the actual necessity of assuming a definite number of special creations 

 of fresh organic worlds en bloc. D'Orbigny knew exactly how many 

 such creations there had been : 



The first creation shows itself in the Silurian stage. After its annihilation 

 through some geological cause or other, a second creation took place a consider- 

 able time after, in the Devonian stage; and twenty-seven times in succession 

 distinct creations have come to repeople the whole earth with its plants and 

 animals, after each of the geological disturbances which destroyed everything 

 in living nature. Such is the fact, certain but incomprehensible, which we 

 confine ourselves to stating, without endeavoring to solve the superhuman 

 mystery which envelops it. 28 



Fourthly — to continue the enumeration of the paleontological diffi- 

 culties — it was objected that, especially within the limits of single great 

 geological formations, the arrangement of fossils in the strata did not 

 exhibit the required order of progression from lower to higher types, 

 but sometimes even reversed that order. This was Sedgwick's principal 

 point in his Edinburgh Review article, as it was that of Hugh Miller in 

 his " Footprints of the Creator," 1849, the most widely circulated of 

 the replies to the "Vestiges." Miller's argument may be summarized 

 in his own words. 29 The latest discoveries in the Silurian and Cambrian 

 series, he declared, do not show the 



sort of arrangement demanded by the exigencies of the development hypoth- 

 eses. A true wood at the base of the old red sandstone, or a true Placoid in the 

 limestones of Bala, very considerably beneath the base of the Lower Silurian 

 system, are untoward misplacements for the purposes of the Lamarckian; and 

 who that has watched the progress of discovery for the last twenty years and 

 seen the place of the earliest ichthyolite transferred from the Carboniferous to 

 the Cambrian system, and that of the earliest exogenous lignite from the Lias 

 to the Lower Devonian, will now venture to say that fossil wood may not yet 

 be detected as low in the scale as any vegetable organism whatever, or fossil fish 

 as low as the remains of any animal? But though the response of the earlier 

 geologic systems be thus unfavorable to the development hypothesis, may not 



28 D'Orbigny, " Cours elementaire de Paleontologie Stratigraphique," 1849, 

 II., 251; cited in Deperet, "The Transformations of the Animal World," 1909, 

 pp. 18-19. 



29 Quoted from the American edition, 27th thousand, 1875, pp. 227-8; the 

 edition has a eulogistic preface by Agassiz, 1851. 



