50 PEOCEEDr!S"GS OF THE GEOLOGICAL SOCIETY. 



Bnt the event of primary importance iu geology during tlie past 

 year has been the abandonment on the part of the Director General 

 and other officers of the Geological Survey, of the Murehisonian 

 hypothesis concerning the stratigraphj^ and the age of the meta- 

 morphic rocks of the Central Highlands. In his letter, published 

 in ' IN'ature,' J^ov. 13, 1884, the Director General, " spatiis conclusus 

 iniquis," was prevented from indicating the share which previous 

 writers had taken in bringing about this result ; but as in these 

 later days the " morning stars " of this reformation have arisen from 

 our Society, and for the most part scintillated in our Journal, you 

 will, I am sure, pardon me if I dwell briefly on the dawn before 

 sunrise. Great as our gratitude should be to those who bring us 

 the perfect light, we should not forget their harbingers in darker 

 times, even if they could not wholly disentangle themselves from 

 the mists of error. 



The view that the crystalline schists of the Central Highlands * 

 were, in the main, metamorphosed representatives of Lower Silurian 

 strata, set forth in fullest detail in the classical papers of the late 

 Sir R. llurchison and Dr. A. Geikie, was alwa^'S stoutly resisted by 

 the late Professor jSTicol ; but the authority of its upholders and the 

 perspicuity of their arguments prevailed with the geological world, 

 and opposition seemed to have expired with the death of ]N'icol. 

 The Murchisonian hj-pothesis was endorsed by every official pub- 

 lication ; it permeated our text-books. The first to raise the standard 

 of revolt against authority was Dr. H. Hicks, who has devoted 

 himself to the identification of Pre-Cambrian rocks which have been 

 absorbed into and annexed by later formations, and their restitution 

 to Archsean, with as much energy as, and better success than, some 

 ethnologists have displayed in the discovery of the " lost ten tribes."' 

 In our Journal for the year 1878 (vol. xxxiv.), Dr. Hicks published 

 a paper " On the Metamorphic and Overlying Eocks in the neigh- 

 bourhood of Loch llaree, Eoss-shire." In this,, while agreeing with 

 Sir R. Murchison and Dr. A. Geikie that there was an ascending 

 succession from the Hebridean series, through the Torridon sand- 

 stone, quartzites, and limestones to the flaggy series (called by those 

 authors the Upper Gneiss), and an intrusive mass of syenitic rock 

 (exposed on the floor of Glen Logan at the base of the last named), 

 he maintained that they were mistaken in supposing the so-caUed 

 Upper Gneiss, exhibited on the left bank of Glen Logan and in the 

 lower part of Glen Docherty, to be a metamorphic group, and had 

 overlooked the fact that true metamorphic rocks belonging to the 

 oldest or Hebridean series reappeared in the floor of Glen Dochertj-, 

 and by gradually rising and probably upfaulting, formed the whole 

 mass of Ben F5^n, whence they passed southwards to constitute the 

 major part of the Central Highlands. 



In the volume for 1880 appeared a paper entitled " Petrological 



^ An excellent sketch of the earlier stages of the controversy as to the ago 

 of the rocks of the Scotch Highlands is given by Mr. W. H. Hudleston, in a 

 paper read to the Geologists' Association in 1879, and printed in Proceedings 

 Gaol. Assoc. toI. vi. p. 47. 



