XIV.] THE GEOLOGY OF THE ALPS. 333 



of the anthracitic system. To this was added in 1860 the 

 discovery by Fillet of nummulitic beds intercalated in the same 

 series near St. Julien in Maurienne. This fact was, however, in 

 accordance with the conclusion previously reached by Sismonda 

 from an examination of Taninge, that " the plants of the car- 

 boniferous period were still nourishing while the seas were 

 depositing the rocks of the nummulitic period." 



The question involved in this controversy had more than a 

 local interest, since it touched the very bases of paleontology, 

 by pretending that in the Alps the laws of succession which 

 elsewhere prevail were suspended, and that the same types of 

 vegetation had continued unchanged from the palaeozoic to the 

 tertiary period. Already, in 1841, Favre had brought forward 

 the suggestion of Voltz, that these apparent anomalies might 

 be explained by inversions of the strata ; but this notion was 

 rejected by De Mortillet and Murchison, as inadmissible for the 

 section at Petit-Coeur. The recognition by Favre, in 1861, of 

 the true age and position of the cargneules and their associated 

 rocks, however, threw a new light on the question, for it was 

 shown that these triassic rocks were interposed at Petit-Coeur 

 between the limestones holding belemnites and the schists with 

 coal-plants. In 1861, the Geological Society of France held its 

 extraordinary session at St. Jean in Maurienne, and there also 

 the succession was made clearly evident, as follows : nummu- 

 litic, liassic, infra-liassic, triassic, and carboniferous; the last 

 resting on crystalline schists. 



Attempts had been made to sustain the supposed Jurassic age 

 of the so-called anthracitic formation, by maintaining that some 

 at least of the coal-plants were Jurassic forms ; but Heer, who 

 had long maintained the contrary, published in 1863 a further 

 study of the fossil flora of Switzerland and Savoy, in which 

 he showed that of sixty species fourteen are peculiar to these 

 regions, while forty-six belong to the carboniferous flora of 

 Europe, and twenty-seven are common with that of North 

 America. One species only has been identified as of liassic age, 

 namely, Odontopteris cycadea Brongn., and is found in a locality 

 near Jurassic belemnites, but associated with no other plant. 



