TACONIO QUESTION IN GEOLOGY. 147 



stvxdies of Favre, Pillet, Gastaldi and others has also been told.'- A similar view was 

 extended to crystalline rocks in other parts of continental Europe, in the British Islands, 

 and in eastern North America, save that for all of these a paleozoic age was generally 

 assigned. The opinions of Mather on this subject were adopted by Logan and others, 

 including the present writer. The brothers Rogers, in 1846, adA'anced a similar view for 

 the rocks of the White Mountains, but abandoned it before 1858. It was not until 1810 

 and 18*71 that the present writer, rejecting entirely the views of this school, asserted the 

 pre-Cambriau age of all the great areas of crystalline rocks, alike in North America and in 

 Europe. Nearly coinciding in time with this, came the independent action of numerous 

 continental geologists, including those already named, and the result has been such an 

 advance of the views of the new school that, in 1881, Callaway could say that " every 

 case of supf)osed metamorphic Cambrian and Silurian has been invalidated by recent 

 researches," and in 1883, Bonney, now President of the G-eological Society of London, 

 wrote that the hitherto accredited " instances of metamorphism in Wales, and especially 

 in Anglesea, in Cornwall, in Leicestershire, and in Worcestershire, have utterly broken 

 down on careful study," *'' as had already been the case in the Alps and in North America. 



§ 190. The last stronghold of the metamorphic school in the British Islands was in 

 the north-west of Scotland, where Cambrian and Ordovician fossiliferous sandstones, 

 limestones and shales, resting upon the ancient granitoid gneisses to the west, are towards 

 the east oveilaid in apparent conformity by a great series of unlike gneisses and mica- 

 schists, which form the Scottish Highlands, and were declared by Murchison and Archibald 

 Giekie, from their studies, to consist of still newer rocks in a so-called metamorphic 

 condition. The structure of this north-western part of Scotland was in fact, according to 

 their teaching, the precise counterpart of that of New England as formerly taught by 

 Mather and his followers, and still supported by Dana. The late Prof Nicol, however, 

 constantly opposed this view of the structure of the Highlands maintained by Murchison 

 and by Giekie, while the present writer, from his lithological studies of the Highland 

 rocks, declared in 18*71 his conviction that the upper gneisses of " the Scottish Highlands 

 will be found .... to belong to a period anterior to the deposition of the Cambrian 

 sediments, and will correspond with the newer gneissic series of our Appalachian region," '' 

 then described as the White Mountain series, — an opinion which was reiterated, after 

 farther examination of the rocks, in a communication in 1881 to the Geological Society of 

 London, when these Highland gneisses were designated as Montalban.*^ 



§ 191. The studies by Hicks of the geology of parts of this region from 1878, and the 

 later and independent ones of Callaway and of Lapworth in other districts, had already, in 

 the beginning of 1883, *' shown the fallacy of the views maintained by Murchison and 

 Giekie as to the geological structure of the Highlands. The united testimony of these 



'- Amer. Jour. Science, 1872, iii, 9, and Chem. and Geol. Essays, pp. 338-342 and 347, 348. Also farther, Trans. 

 Koy. Soc, Canada, vol. i, sec. iv, pp. 182-190. 



'"' Callaway, Geological Magazine, Sept. 1881, p. 423, and Bonney, ibid., Nov., 1883, p. 507. 



^* Hunt, President's Address before the Amer. Assoc. Adv. Science, 1871, and Chem. and Geol. Essays, p. 272 



^^ Proc. Geol. Soc, London, in Geological Magazine, 1882, ix, 39. 



^ Hicks, Quar. Geol. Jour., 1878, xxxiv., 816 ; Geol. Mag., 1880, vi ; also Quar. Geol. Jour., 1883 (with appended 

 notes by Bonney), in Jabstract in Geol. Mag., March, 1883, x, p. 137. Callaway, il/id., x, pp. 139 and 33G ; and 

 Lapworth, ihul., x, i)p. 120, 192, 337; alsci Callaway on Progressive Metamorphism, ■)7nV7.,May, 1884; and summarie.s 

 in accounts of the Progre.ss of Geology in the Keports of the Smithsonian Inst, for 1882 and 1883. 



