Vol. 60.] AGE OF THE LAKE OF GENEVA. 317 



phenomena in support of that view are, in the case of the Lake 

 of Geneva, on a grander scale, more striking, and, if anything, 

 even more conclusive. 



Discessjox. 



Prof. Gael Schmidt remarked that the parallelism claimed by the 

 Author as existing between the Lakes of Zurich and Geneva was 

 not very clear to him : the formation of the first-named lake, at 

 right angles to the strike of the Molasse-country, was easier to 

 explain than that of the last-named lake. In his opinion, the 

 structure of the Luke of Geneva might be more nearly compared 

 with that of Lucerne : the development of the glacial formations 

 was very similar in the two cases. He pointed out the increasing 

 difficulty experienced in distinguishing the three formations of 

 Schotter as one approached the Alps, and he agreed with Lugeon, 

 Schardt. and other observers in regard to the uncertainty which 

 attended this question. He commented on the fluctuation of opinion 

 concerning the flexures of the Molasse, and observed that there 

 seemed to be nowadays a tendency to revert to the older theories. 



Prof. Bonnet thought that the comparison of the lakes in the 

 same Alpine zone could not fail to bring about valuable results. 

 He had examined, in August 1891, the section below Geneva, to 

 which the Author referred, and now read some extracts from notes 

 written on the spot. At that time he was thinking more about the 

 hypothesis of glacial excavation for the lake, than of the date of its 

 formation. What he then saw, as these extracts showed, had con- 

 vinced him that the gravels on either side of the Rhone must have 

 been formed by that river and not by the Arve alone ; that ice had 

 subsequently passed over them, without any appreciable disturbance ; 

 and that the pebbles were too much rounded to have been formed 

 by torrents flowing from the end of a glacier near at hand, — they 

 must have travelled at least several miles. Since that date he had 

 examined, sometimes under the Authors guidance, the gravels and 

 morainic deposits in the Limmat Valley and elsewhere, with the 

 result that the late date of the Alpine lakes had been gradually 

 forced upon his mind. He realized, as plainly as any one could do, 

 that this was a startling conclusion, but we must remember that the 

 !Xorth American lakes showed that there had been considerable 

 movements in comparatively-recent times, and this was not the only 

 instance which might be quoted. 



POSTCRIPT TO TEE DlSCUSSION. 



"The Aethoe, not having been present at the discussion, wishes 

 to point out that Prof. Schmidt's opinion that the structure of 

 the Lake of Geneva may be more nearly compared with that of 

 Lucerne than with that of Zurich, is invalidated by the physio- 

 graphical fact that the Lakes of Zurich and Geneva each lie in 



