6 THE TRANSFORMATIONS OF THE ANIMAL WORLD 



presence of extinct species quartered in certain places, 

 and even following one another in a certain chrono- 

 logical order. These ideas, somewhat inexact 

 moreover, could not fructify in a medium still too 

 deficient in the most essential data of stratigraphic 

 geology. 



It was only in the second half of the eighteenth 

 century that methods of determining the age 

 of sedimentary soils by means of fossils were 

 able to triumph in geology, under the influence 

 of the remarkable generalizations of Buffon in the 

 Epoques de la Nature, and still more of the local 

 monographs of Fuchs in Thuringia, of Werner in 

 Saxony, of Giraud - Soulavie in Auvergne, and es- 

 pecially of William Smith on the secondary forma- 

 tions of the London basin. 



At the dawn of the nineteenth century, the import- 

 ance of fossils was at last everywhere appreciated 

 at its right value, and their infinitely varied forms 

 became the objects of study to numerous scholars, 

 whose descriptions assumed a new character of 

 exactness, thanks to the definitive adoption of the 

 binominal (i.e. generic name and specific name) 

 Linnsean nomenclature. The hour had at last 

 arrived for the production of the genius-inspired 

 work of Georges Cuvier. 



