191 



ation is developed, this great group of strata ought not, on 

 grounds merely theoretical, to be regarded as pertaining to any 

 period but that which is typical and characteristic of the main 

 coal-deposits of the rest of the globe. Should the Anthracites of 

 northwestern France prove, on a reexamination, to be also of 

 the same age, then, but not until then, will the ingenious hypo- 

 thesis of M. de Beaumont, which assigns to these and the Ame- 

 rican coals the same epoch of disturbance and uplift, because of 

 their coincidence in direction on the sphere, maintain itself un- 

 impaired. 



Mr. Desor called the attention of the Society to a pas- 

 sage in one of the last works of M. Elie de Beaumont, 

 entitled " Notice sur les Systemes de Montagnes les plus 

 anciens de I'Europe," in which the author formally dis- 

 countenances the opinion entertained by some geologists, 

 that the upheaval of each of the great mountain chains has 

 caused the destruction of the whole animal and vegetable 

 population of the globe. He refers especially to the eleva- 

 tion of the hills of Bocage, in France, and of the chain 

 of the Pyrenees, as having occasioned no organic change 

 whatever. In the latter case the same eocene species 

 occur both in the uptilted strata of the mountains, and 

 in those abutting horizontally against them. If it be thus 

 proved that the elevation of such a gigantic chain as the 

 Pyrenees, did not affect the animal world, what authorizes 

 us to infer that the upheaval of other and lesser mountain 

 chains should have caused the destruction of all living 

 beings, as it is assumed in some of our text-books. Mr. 

 Desor expressed the hope that the time may not be far 

 distant when paleontologists will satisfy themselves that the 

 changes which we witness in the history of past geological 

 ages have taken place gradually, and are not the result of 

 violent revolution. 



Prof. Rogers gave an account of the general geological 

 character of the Jura range of mountains. On a former 

 occasion he had stated, that the force by which they had 



