Correspondence — Mr. H. S. Hoivorth. 569 



sionally of about 1,000 feet. The deposits, where fully developer!, 

 consist of Upper Boulder-clay, Middle Sand and Gravel and Lower 

 Boulder-clay ; together they sometimes attain a thickness of from 

 100 to about 130 feet. Certain peculiarities in the distribution of 

 the deposits were described. The tripartite arrangement never 

 occurs in the valleys in the mountainous district. Boulder-clays, 

 indeed, sometimes occur here, but sands are more common. The 

 distribution of the boulders from the more remarkable rocks was 

 described ; tables of these were given, as also of the maximum 

 height above the sea at which each occurs. The origin of the 

 deposits was next discussed. The author is of opinion that the 

 presence in the Lower Boulder-clay of boulders derived from such 

 widely different sources can only be explained by floating ice, but 

 that the correspondence of the materials of the clay with rocks in 

 the vicinity shows that glacier-mud produced the finer elements. 

 The Middle Sand and Gravel he considers due to denudation of the 

 above matei'ials during a period of emergence. The Upper Boulder- 

 clay he attributes to a second period of submergence corresponding 

 generally in its conditions with the former one. The gravel mounds 

 are probably caused by the stranding of bergs at the end of this 

 period. 



THE SUDDEN EXTINCTION OF THE MAMMOTH. 



Sir, — I was flattered by finding two communications in the last 

 Number of your Magazine devoted to the papers I have, by your 

 favour, printed in that most catholic of geological publications. It 

 is some proof, at all events, that the papers have attracted notice. 

 With one of these communications, signed Ignoramus, I most com- 

 pletely agree. There is no pedantry more transparently foolish 

 than that which dots its pages with quotations in a foreign tongue. 

 In my case, the excuse is that I was writing as a heretic, upon a 

 question in which a large proportion of English geologists are 

 ranged on the other side, and therefore in quoting critical and 

 important passages, to avoid all pretence that I was garbling or 

 introducing my own personal" equation into my authorities, I thought 

 it better to give the exact words of the author. I will not trans- 

 gress the same way again ; but if I have occasion to quote, I will 

 give the most faithful translation I can command. To Mr. Eeid 

 I must devote a larger space. First, let me thank him cordially 

 for the terms in which he has spoken of my papers. It is a great 

 point gained to have no quarrel about the facts, which are therefore 

 at the disposal of all your readers. Nor is there any quarrel about 

 the cardinal postulate upon which my view is based, and which is 

 shared by Mr. Eeid, if I understand his letter rightly, with the 

 Eussian geologists, namely, that the Mammoth lived and died where 

 his remains are found. 



Mr. Eeid says the conclusions I have drawn are quite imwarranted 

 by the facts. This is merely a strong phrase to use of conclusions 



