ANNIVEESAET ADDRESS OF THE PEESIDENT. 67 



find the rocks distinctly assume a more bedded aspect; compact 

 glistening schists, for instance, occurring near that village ; but even 

 these, in their present condition, cannot be regarded as indications of 

 true bedding. Everywhere in this district, except perchance where 

 there appears some slight local disturbance, the foliation and the 

 apparent bedding have a strike roughly AV.S.W.-E.IST.E., or a few 

 degrees further from theE.-W. line, that is, one corresponding with 

 the general strike of the elongated area of the massif itself. It 

 would thus follow that the rocks exposed in the eastern part of the 

 northern face of the massif would probably be among the highest in 

 succession, assuming the coarsely crystalline nucleus to be the 

 oldest ; and the less disturbed district, in the lower part of the Gad- 

 menthal, may, I think, be taken as a suitable place for examination. 

 Here we find the crystalline massif emerging from beneath great 

 beds of Mesozoic rock, which crest the right bank of the Gadmer 

 Aa, and occur occasionally in outliers on its left bank. I have 

 examined in passing the crystalline series from Im Hof to the 

 Susten Pass. Everywhere they have a more definitely foliated 

 character than in the district last described. At Im Hof, just 

 beneath the newer series, we find a rather granitoid rock ; pro- 

 ceeding then to Muhlestalden, the rock for a time retains generally 

 the same aspect, then becomes more fine-grained and rather more 

 schistose. Near the village we find intercalated in the gneiss a 

 band of white crystalline limestone. It is about four yards thick, 

 dipping roughly at about 50° a little S. of S.S.E. The transition 

 from the gneiss is rapid, occupying, so far as I could see, about 3 or 

 4 inches ; but this was, unfortunately, the most perishable part of the 

 rock. A slight fissility in the marble corresponds with the foliation 

 in the gneiss, and both with the bedding indicated by the former. 

 I do not think it possible that this limestone could be the result of 

 infiltration. As we ascend from this point towards the basin occupied 

 by the glaciers of the Stein Alp we pass over gneisses generally similar 

 to the last described. jN'ow and then these become rather distinctly 

 foliated, and occasionally exhibit an apparent stratification, indicated, 

 for example, by a rather rapid change from a band at least several 

 feet thick, where a dark mica is deficient, to one where it is rather 

 abundant. Again, cases may be noted where the layers of mica 

 have distinctly undergone crashing and corrugation since their 

 formation ; and I observed that, on the whole, the rock was less 

 fissile in the direction of a micaceous layer than is often the case 

 among crystalline rocks. As we descend from the summit of the 

 pass towards Wasen we notice similar rocks ; but in the neighbour- 

 hood of that village (after a very considerable interval in which 

 little or no rock is exposed in the bed of the glen), we come upon 

 the granitoid rock, already mentioned as bordering the Eeuss. 



The evidence of the Haslithal and of the glens occupied by the 

 two glaciers of the Aletsch (though I do not pretend to have 

 minutely explored the latter, and it is many years since I walked 

 through the former) indicates that rocks similar to those described 

 in the valley of the Eeuss extend far away in a AV.S.W. direction. 



