EUROPE BEFORE ARRIVAL OF MAN 



tinent, and now constituting the Silurian rocks of 

 Europe. If all this sediment were to be arranged 

 in a longitudinal pile, according to Professor 

 Archibald Geikie, it would make a mountain 

 ridge 1 800 miles long, 33 miles wide, and some- 

 what higher than Mont Blanc. At the close of 

 this long period ridges of land had begun to ap- 

 pear on the sites of Spain and Switzerland. By 

 the Carboniferous period the central parts of 

 Europe had risen so as to form an archipelago 

 of low islands, surrounded by lagoons and salt 

 marshes, covered with dense jungles of ferns 

 and club-mosses. On the islets grew thick for- 

 ests of pine, and as repeated epochs of submer- 

 gence brought all this teeming vegetation under 

 water, it became covered with detritus of mud 

 and sand from the northern highlands, and in 

 this way was preserved to form the coal-beds of 

 Europe. By the Triassic period we find the 

 general elevation of Europe increased, so that 

 instead of an archipelago lying amid lagoons we 

 have a continent thickly dotted over with salt 

 lakes ; but in the next or Jurassic period the 

 whole centre of the continent was laid under 

 water again. The extent and shape of the Euro- 

 pean sea of the Cretaceous period are indicated 

 by the extent of the chalk which was formed on 

 its floor, and of which Professor Huxley has given 

 such a graphic account in his lecture " On a Piece 



