Antrim and Scotland. 263 



which the British Islands were united, and which, 

 embracing Iceland, spread far to the north and west into 

 the area of what is now the Atlantic, and on the south 

 was united to Africa, when as yet the Mediterranean had 

 no existence. 



In those days our British mountain lands formed of 

 palaeozoic rocks were mountainous then as they are now, 

 but higher ; and elsewhere, especially after the close of 

 the formation of the Eocene strata, the Alps, the Car- 

 pathians, and the Pyrenees, first rose into prominence as 

 mountain chains, at the foot of which in Switzerland 

 were great lakes, from the collective strata of which 

 Professor Heer has numbered 900 species of plants and 

 nearly as many insects, all such as must have lived in a 

 subtropical climate, probably warmer than that of our 

 Devonshire area, if we may judge by the fossilised 

 remains of date-palms. 



When, however, we travel northward from Bovey 

 Tracey, the case is different, and to make this plain, I 

 must lead you for a moment through the Western Isles 

 of Scotland, and far beyond, among the islands of the 

 Arctic Sea. 



In Antrim, the island of Mull, and on the mainland 

 opposite, and in Staffa, Rum, Eigg, Canna, and Skye, 

 the Miocene rocks consist chiefly of the lava-flows and 

 ashes of great terrestrial volcanoes. These, as they 

 accumulated, overflowed and filled up the undulating 

 valleys of chalk in Antrim, of Oolite and of Silurian 

 gneiss in what is now the west of Scotland, and in the 

 intervals of eruptions, lakes were sometimes formed, 

 and terrestrial soils accumulated on the sides of vol- 

 canoes, some of which, according to Mr. Judd, grew by 

 accretion of volcanic matter till they rivalled Etna in 

 height, and seemed as if they might last for ever, but 



