XXXIV PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Eon, on the structure of the Alps, Apenmnes and Carpathians, which 

 cleserTedlv occupies an entire Number of vour Quarterly Journal*. 

 It comprises a m^asterly summary of the labours of those who had gone 

 before him, in a very difficult field of inquiry, as well as a luminous 

 account of his own personal investigations, and should be studied by 

 every one who is desirous of knowing what point the modem progress 

 of geology has reached. On various important questions of which he 

 treats, and in which I entirely agree with him, I cannot enter at pre- 

 sent, but there is one leading conclusion established hi his memoir 

 which bears specially on the theory selected for discussion in this Ad- 

 dress. He proves, as it appears to me in a satisfactory manner, that 

 those stupendous movements to which the loftiest chain in Europe 

 owes its complicated structure, and by which its component strata have 

 been dislocated, fractured and contorted, belong to a very modem aera 

 in the earth's history. In the long calendar of geological events, the 

 Eocene period is the first which presents us with a fossil flora and 

 fauna, both terrestrial and aquatic, of a very complete character, com- 

 prising mammalia both of the sea and land, of all the principal classes, 

 now contemporary with man. It would doubtless be rash to assume 

 that no plants or animals of equally high organization may not have 

 pre-existed on this globe, for the recent progress of discovery in our 

 science puts us on our guard against founding hasty generalizations 

 on mere negative evidence. The fossil skeletons of saurians discovered 

 in the coal-measures of Saarbriick near Treves are stiU fresh in our 

 recollection, as are those footprints of the same age first detected by 

 Dr. King, and which I have myself examined at Greensburg in Penn- 

 sylvania. 'We are waiting also with impatience for more minute details 

 respecting some reptilian footprints of a still more ancient date, found 

 by ^Ir. Isaac Lea in the old red sandstone at Pottsville, near Phila- 

 delphia ; nor have we forgotten the tracks of nmnerous birds, observed 

 m the red shales and sandstones of Connecticut, of a date nearly bor- 

 dering on palaeozoic times. Such facts, like the unexpected discovery 

 of the Stonesfield marsupials, a quarter of a century ago, wam us 

 against the presumption of taking for granted, that our present know- 

 ledge of the earhest occurrence of a particular class of fossils in stra- 

 tified rocks, can be reasoned upon as if it aff'orded a true indication 

 of the first appearance of a particular class of beings on the globe. 

 * Vol. V. Part i. 1848, December. 



