A Mountain Tulip. 1S5 



or thereabouts, this condition of things began to 

 change ; the cUmate of the north became more genial ; 

 and ever since that date our sober planet has oscil- 

 lated within gentler limits, producing only such alter- 

 nate results of annual summer and winter as those 

 with which we ourselves are now familiar. 



\\'hen the glaciation was at its worst in the 

 northern hemisphere, almost the entire surface of the 

 European continent, from Scandinavia and Lapland, 

 to England, Belgium, and central German)', lay buried 

 beneath one unbroken sheet of permanent ice. But 

 when the conditions were a little less severe, local 

 glaciers radiated from the chief mountain bosses of 

 Scotland, Wales, and the Isle of Man, and ground 

 these deep grooves and scratches on the worn surface 

 of the denuded rock. At length the climate began 

 to mend slightly ; and then the plants and animals of 

 the Arctic zone spread uninterniptedly over the whole 

 of northern Europe, from the limit of pack-ice to at 

 least the southern slope of the Alps on the Italian 

 side. Remains of these glacial animals — Arctic lem- 

 mings, musk sheep, white hares, reindeers, Alpine 

 marmots, and snowy owls — are still found among the 

 bone-caves and river drift of the intcrglacial ages in 

 various parts of Europe, from Scandinavia to the 



Tuscan grottoes. At the same time we may be pretty 

 9 



