88 Geological Society of London. 



view the best of the old-fashioned thoughts and ripe opinions, whilst 

 Ice-action is everything to some, — whilst Kain-action is the universal 

 agent with these, and Sea- waves with those, — whilst Negative Evi- 

 dence is the bug-bear of one party, Homotaxis a puzzle for another, — 

 the gradual out-coming of new forms the belief of some, and the 

 uniformity of nature, both physical and vital, the dogma of others. 



Once more, then, geologists have to welcome a revised edition of 

 one of the most valuable of geological works, which, only by the 

 use of much small type, has been made to contain within reasonable 

 compass the great number of important additions to his Science that 

 the author has had to notice. The many counties in England, Wales, 

 Scotland, and Ireland that have their structure elucidated and their 

 mineral wealth more or less treated of in this book, must all supply- 

 many students and thankful readers. The traveller finds it of use, 

 not only in Europe and North America, but in other parts of the 

 world; indeed, an educated man anywhere can find something of 

 interest in its less technical pages. The geologist proper well knows 

 its value ; for, though he may here and there find more of the per- 

 sonal history of Silurian research than he cares for, yet never, per- 

 haps, will another such work be produced, in illustration of the sub- 

 ject-matter it treats of, characterized by so full and perfect an associa- 

 tion of the results arrived at by co-operating geologists, of all nations, 

 clustered round a worthy centre — the author of this new edition of 

 " Siluria," — a work rich in good facts, well arranged, and written 

 by an earnest, mature, and philosophic mind. 



Geological Society of London. — December 18th, 1867. — 

 Warington W. Smyth, M.A., F.E.S., President, in the Chair. The 

 following communications were read : — 1. " On the Parallel Roads 

 of Glen Eoy." By Sir J. Lubbock, Bart., F.R.S., Pres. Ent. Soc. 



The author did not enter into the question as to the manner in 

 which the valleys were filled with water, but assuming that the 

 '* roads " or " shelves " represent ancient water margins, he at- 

 tempted to point out the manner in which they were produced. 



The theory of Macculloch, which has been adopted by Darwin, 

 Lyell, and Jamieson, is, that the matter brought down by frost, 

 rain, etc., from above, was arrested by the water, and heaped up by 

 the action of the waves. If this was the true explanation, however, 

 Sir John argued that the roads would form an excrescence on the 

 slope of the hill, which they do not ; that their breadth must vary- 

 considerably ; that the slope of the roads would be towards the hill ; 

 and that the roads would be widest where the inclination of the hill 

 is less than usual, and where streams bring down matter from above; 

 whereas, on the contrary, in these places the roads disappear. 



In opposition to this theory. Sir John then argued that the action 

 of the waves, under such circumstances, would be to throw matter 

 down, and not up. Given a slope of angular debris standing at the 

 angle of repose, partly in air and partly in water, the angle will be 



