438 HISTORY OF GEOLOGY AND PAL/EONTOLOGY, 



groups, referring all the deposits from the Caradoc series 

 downwards to the Cambrian series. The high-spirited Cam- 

 bridge Professor could, however, make no impression upon 

 his contemporaries against his influential opponent, who in 

 1855 became the General Director of the Geological Survey. 

 Indeed, the Council of the Geological Society in 1852 placed 

 themselves openly on Murchison's side by passing a resolution 

 to decline on principle any communication made by Sedgwick 

 on the classification and nomenclature of the older Palaeozoic 

 deposits. 



Nevertheless Sedgwick adhered to his own classification, and 

 published a historical review of his researches on the Palaeozoic 

 rocks of Great Britain, which appeared as an introduction to 

 an illustrated catalogue of Cambrian and Silurian fossils drawn 

 up by J. W. Salter. Sedgwick, in this last scientific exposition 

 of his views, for he died in the year of its publication (1873), 

 emphasised once again the independence of the Cambrian 

 deposits, showed that the Cambrian system contained charac- 

 teristic fossils, distinct from those of the Silurian system, and 

 that it was consequently founded upon secure palaeontological 

 data. In the end Sedgwick has been found right. The 

 Cambrian system, although with a certain modification of its 

 limits, is now recognised as an independent geological system 

 represented throughout the whole earth. 



Special Stratigraphy. The general framework of strati- 

 graphical teaching had thus been constructed by the works of 

 Lyell, Deshayes, and Bronn on Cainozoic rocks, by those of 

 Smith, Conybeare, and Phillips on Mesozoic rocks, and those 

 of Sedgwick and Murchison on Palaeozoic rocks. It was left 

 for younger generations of geologists to work out the finer 

 details and more accurate division of the successive formations. 

 This task was willingly undertaken by a thousand diligent 

 hands, not only in Europe but throughout the world. Little 

 change has been made on the limits of the main divisions 

 (formations or systems) of the stratigraphical framework, but 

 the work of determining palaeontological sequences in greater 

 and greater detail is still in full progress, and the recognition 

 of the minor stratigraphical members within the formations 

 varies from time to time with the increasing knowledge and 

 understanding of the geological structure of the earth's crust 

 in Europe and other parts of the world. 



