On (he Formg assumed by Granite and Gneiss. 319 



and granular, liko the basalts of StafFa and tho other Hebrides. 

 Now, as observations made in Germany and Scotland have 

 fully proved that such augitic rocks proceed from the interior 

 in irregular masses and veins, and have spread themselves 

 over tho surface of the strata that have been broken through, 

 it cannot bo doubted, that each one of the West Gothland 

 hills also contains a basaltic cylinder, irregular mass, or vein, 

 which unites tho upper bed with a basaltic or augitic mass 

 that extends far beneath the granite. The hill of Billingen 

 is quite similar to the Meisner in Hesse, in which numerous 

 shafts, leading from the outer circumference to the interior, 

 have brought to light the internal basaltic nucleus. The gneiss 

 every where surrounds these hills like a projecting rampart, 

 but is never in immediate contact with them, and it is, in fact, 

 very much to bo doubted, if in the whole of Skaraborgslan 

 there is a single point where gneiss or granite forms the un- 

 derlying mass of the hills composed of upraised transition 

 strata. 



It is, therefore, the basaltic mass concealed in the interior 

 which has protected the silurian strata that were penetrated 

 and raised by it, and which has withdrawn them from the 

 metamorphic action of the granite, and the other matters that 

 accompanied it at its protrusion. A little further (at the 

 Hunneberg, near FIoh-Kyrcka, about a German mile distant), 

 the basaltic rock terminates, and the granite again presents 

 itself at the surface, at least it does so in Smoland as far as 

 Schonen, but not in Esthland and Liefland. 



It is with some surprise that we again meet with the con- 

 vex and smooth layers of granite in Switzerland. One would 

 not have anticipated this occurrence in a chain where there is 

 so much disturbance, and in which the mountains rise into 

 such bold peaks and ridges. They are, however, no longer 

 observable on the summits, but in the valleys they are exhi- 

 bited of large dimensions and of wonderful extent. There is 

 a fine example in the well known Hollenplatte, above Handeck, 

 on the Grimsel, which is represented in Agassiz' work as an 

 illustration of glacier action. Saussure, on the other hand 

 (iii. p. 459), saw there strata., one above the other, *' coiivexes, 

 posees en retraite Ie$ uncs sur les autres, comme dHmmenses gra- 



