Ixii PKdCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Lias and the Coal-formation, and the battle-field of the discussion was 

 removed to St. Jean de Maurienne. The fourth period extends from 

 1860 to 1863. It began with the discovery of Nummulites at 

 Maurienne, and continued to the close of the discussion. Then it 

 was that the recognized presence of the Trias and the Infralias, as 

 well as the position of the Nummulites found in a formation hitherto 

 considered by M. Scipion Gi^as as anthraxiferoiis, combined with the 

 mineralogical character of the rocks, their stratigraphical position, so 

 long misunderstood owing to the numerous contortions of the beds, 

 and the fossils which they contained, proved the presence of the real 

 Carboniferous formation in the Alps. 



The fact was generally admitted at the meeting of the Prench 

 Geological Society at St. Jean de Maurienne in 1861. The same 

 results were applied to Dauphine and Provence ; and finally M. Heer, 

 who had so completely mastered the mystery of the fossil flora of 

 Switzerland, published in 1863 a memoir respecting the flora of the 

 Carboniferous formation in Switzerland and Savoy, in which he 

 showed that not one single plant of the Carboniferous formation of 

 the Alps was found either in the Lias or in the Trias. 



Is it not a curious fact, observes M. Pavre, that it required thirty- 

 five years of discussion and of argument to clear up a point of 

 Alpine geology ? It has led, however, to a much better knowledge 

 of details ; and now questions relating to the age of a formation 

 can be solved as well in the Alps as in the neighbouring countries, 

 and the charge of backwardness can no longer 'be maintained against 

 the geology of the Alps. 



In concluding this precis, M. Pavre gives a list of the various 

 geologists who had adopted the diff'erent views respecting the age of 

 the anthraxiferous-beds of Switzerland. In this list he places my 

 name amongst those who referred this formation to the Lias. Now 

 although there can be no discredit in being placed in the same 

 category with such names as Elie de Beaumont, Sismonda, CollegTio, 

 Eoget, (fee, I think it right to say that the only part I took in the 

 discussion was this, that in the anniversary address which I de- 

 livered from this chair in 1856, after giving a sketch of M. Scipion 

 Gras's memoir on the subject, I stated, on the strength of the alleged 

 superiority of evidence derived from the fauna of a formation as to 

 its age, over that derived from its flora, that '' the weight of evidence 

 appears to be in favour of referring the whole formation to the 

 Jurassic rather than to the Carboniferous period," 



M. Pavre also adds that, if the discussion had terminated in 

 the contrary sense, the whole question of palaeontology would have 

 had to be seriously modified. If it had been proved that the coal 

 plants were still living during the Liassic period, the value of fossil 

 botany would have been destroyed, as it would no longer have served 

 to characterize a formation. The labours of Prof. Heer have saved 

 us from this catastrophe. 



"With reference to this question I may also direct your attention 

 to another memoir in the same number of the ' Bulletin ' by M. 

 Lory, in which he endeavours to explain the stratigraphical anomaly 



