GEOLOGY. 447 



completely metainorphic rock which is not of Archaean age. Certainly 

 tbe stock instances of metaniorphism in Wales, and especially in Angle- 

 sea, in Cornwall, in Leicestershire, and in Worcestershire, have utterly 

 broken down on careful study. Outside the English geological survey 

 probably no person who can use a microscope believes that the schists 

 of Anglesea are altered Cambrian, or that the slates of this age were 

 melted down into the quartz-porphyry of Llyn-Padaru." He adds : " No 

 inferences with regard to metamorphism can be accepted until they 

 have been fully confirmed by the evidence of the microscope." 



He concludes that his own and others' studies show that the crystal- 

 line schists and gneisses of the Alps existed in their present condition 

 long before the carboniferous period, and insists upon the fact that 

 throughout the various regions of the Alps we everywhere pass from 

 comparatively unmetamorphosed rocks of known age to a highly meta- 

 morphosed rock, of which it can only be said that it is immensely older. 

 In this latter series, moreover, he declares we " can trace a certain litho- 

 logical and stratigraphical sequence leading upward through a series of 

 groups - - - from the coarse granitoid gneisses and protogines to 

 the topmost well-stratified but still truly metamorphic schists," and con- 

 cludes that we have no evidence that any of these crystalline foliated 

 roeks of the Alps are as youug as the Cambrian period. 



Bonney has also described further the Miocene conglomerates of the 

 so-called Xagdflne of the Bigi, and refers to the frequent indenting and 

 pitting of the included pebbles, a phenomenon often noted and described 

 in this and other similar conglomerates, which he ascribes in part to 

 direct pressure and in part to the action of water, localized and intensi- 

 fied by the pressure of adjoining pebbles. He objects to the notion that 

 such mechanical changes depend upon high temperature, as some have 

 suggested. 



THE SCOTTISH HIGHLANDS. 



A further contribution to the geology of the crystalline rocks of Scot- 

 land has been given by Lapworth in an extended memoir entitled '* The 

 Secret of the Highlands," in which he discusses the vexed question of 

 the relations of the crystalline and the uncrystalline rocks, arriving at 

 results similar to those of Callaway, already set forth. In the coast re- 

 gion of Durness and Eriboll, in Sutherlandshire, it has been asserted by 

 previous observers that we have a distinct ascending succession from 

 the basal Hebridian gneiss through fossiliferous Paleozoic limestones 

 to the micaceous gneiss and schists of the central Highlands. Accord- 

 ing to Lapworth, we have at the base a great mass of coarse-grained 

 massive gneiss, composed of feldspar and quartz, with hornblende, and 

 more rarely with mica, the strata being nearly vertical, with a north- 

 west and southeast strike. The:«e rocks are the Hebridian, Lewisian or 

 Laurentian - ueiss of different observers. Besting unconformably upon 

 this ancient gneiss is a second body of strata, gently inclined, with a 

 general northeast and southwest strike, and consisting of two divisions, 

 lithologically very distinct. The lower is made up of a quartzite with 



