Reports & Proceedings — British Association. 555 



economic applications, and shows considerable promise in 

 the correlation of sands in oil regions. The first chapter deals 

 briefly with methods of sampling, treatment, and microscopical 

 examination. One would rather like some further elucidation 

 of the statement that " microchemical reactions are inadmissible 

 with detrital grains". The author insists very strongly on the 

 necessity for elutriation for the separation of the finer 

 fractions, but apparently omits to point out that it is usually 

 impossible to determine the mineral character of the finest grades. 

 It is unlikely that these will ever be of much use for correlation 

 purposes. The mineralogy of the finer-grained sediments is still in 

 a very unsatisfactory state in spite of the admirable pioneer work 

 of Hutchings. Nearly half of the book is occupied by tables of the 

 physical and optical properties of the minerals commonly occurring 

 in sands, illustrated by useful drawings, the work of Mr. G. M. Part. 

 The last two chapters discuss in a somewhat sketchy manner the 

 principles of petrographic correlation of sediments and the bearings 

 of sedimentary petrography on palseogeographical problems. There 

 is a useful bibliography, which, however, is mainly confined to 

 British publications. 



REPORTS AND PROCEEDINGS. 



British Association, Hull. 

 Section C. — Geology. 



Discussion on Wegener's Hvpothesis of Continental Drift. 

 (a) Opener, Dr. J. W. Evans, F.R'.S. 



The occurrence of allied forms of life on continents separated by 

 great oceans has given rise to speculations as to former connexions 

 between them. TLere is in some cases also considerable similarity 

 in the geological features on the opposite sides of the oceans, 

 especially in the case of the Palaeozoic rocks of the two sides of 

 the Atlantic, and of the Permo-Carboniferous fonnations of India, 

 Australia, South Africa, the Falklands, and South America. It was, 

 however, j)rimarily to solve the distribution of life forms that 

 Dr. Wegener formulated his hypothesis of the dispersion of the 

 continental masses. He supposes these to have been aggregated 

 together as late as the Tertiary period, and North America to have 

 been in close proximity to Europe even in the Pleistocene. The 

 continents are, he thinks, slowly drifting from the poles, and from 

 east to west. The former movement is ])elieved by him to be proved 

 by observations at European observatories and at that at Washing- 

 ton, showing a decrease in latitude, but recent observations on the 

 Pacific coast indicate that latitude is there increasing. He is under 

 the impression that America is going west faster than Europe, 

 and that the longitude of Cambridge, Mass., is increasing, while 



