Al^TIflVEESAEY ADDRESS OP THE PRESIDENT. XCl 



raised up, violently disturbed and abraded, the necessary result 

 must have been great irregularities of surface, great inequalities 

 of ground, here elevated ridges and there corresponding depres- 

 sions ; and what is more probable than that some of these depres- 

 sions, particularly such as occurred near the northern flank of the 

 Alps and the southern flank of the Jura, became the recipients 

 of those torrential vfaters which, during and subsequent to this 

 period of convulsion, rushed down the mountain-sides, thus form- 

 ing those very lakes we are now examining ? 2. Might we not 

 expect that the very fact of the elevation of these mountain-ridges, 

 on the very site where from the earliest geological periods moun- 

 tains and continents and islands are known to have existed, would 

 have produced corresponding depressions parallel with the axis of 

 their line of elevation, and in their immediate neighbourhood. 

 Such a solution appears to me more probable than the scooping- 

 out of rock-basins by glacial action. Of course this explanation 

 does not apply to all Alpine lakes, particularly those on the Italian 

 side, I therefore only venture to offer it as a probable solution in 

 some cases. 



While on this subject I wish also to call your attention to an 

 interesting correspondence between MM. Gastaldi, Mortillet, and 

 Omboni in the fifth volume of the ' Atti della Societa Italiana 

 di Scienze Naturali.' From this it appears that the two former 

 writers adopt the views of Prof. Eamsay only to a very limited 

 extent. Looking at the excavating powers of glaciers with greater 

 moderation, they do not attribute to them the gigantic task of 

 having hollowed the lake-basins out of the hard rock ; but merely 

 that of having forced out, partly by dissolution and partly by 

 pushing forward, the soft alluvium which had been deposited in 

 preexisting valleys and hollows, and which belonged to the pre- 

 glacial period, when the plain of the Po in Lombardy was formed, 

 and which extended like so many fiords up the Alpine valleys. 

 M. Omboni, who takes another view, considers that these oldvalleys 

 and basins, into the question of the formation of whicli he does not 

 enter, were already filled with ice before the deposit of the alluvium 

 of the plains of Lombardy, and that on the introduction of a 

 warmer period the ice melted, and the preexisting hollows became 

 filled with water, the overflow of which cut its way through the 

 terminal moraines. This explanation seems quite satisfactory, as 

 far as the Lake of Garda is concerned. 



Postglacial Period. — I find that it is impossible for me to carry 

 out my original intention of referring to the discoveries of Falconer, 

 Prestwich, Evans, and many others, respecting the postglacial 

 period, and those deposits, both in this country and on the continent 

 of Europe, where evidence of man's existence has been found con- 

 temporaneous with the remains of animals now extinct, but which 

 appear still to have lived on after his appearance on the earth. I 

 regret this the more as it is by no means an unimportant fact. It 

 adds another link to that chain of evidence by which we are daily 

 becoming more and more convinced that no real natural breaks 



