YOUNGER YEARS OF A PLANT. 159 



for the slightest crevice in the bare rock suffices to arrest 

 some of the invisible germs which are constantly floating 

 in the air, and affords them a home. They yield nothing 

 in industry and perseverance to their humble predeces- 

 sors ; hardy little laborers in the same great work, they 

 seem to delight in the clouds and storms of a wintry 

 season, when all other verdure fades. They find a home, 

 and live and thrive with equal contentment in the burning 

 cinders of volcanic islands, like Ascension, on which they 

 formed the first green crust after it had risen from the 

 ocean, and on the tempest-beaten boulders of Norwegian 

 granite, which they cover with a scarlet coating, well known 

 as the violet stone and full of rich, sweet perfume. As 

 they wither and die, minute layers of soil are formed, 

 one after another, until grasses and herbs can find a foot- 

 hold: shrubs with their hardy roots now begin to inter- 

 lace the loose fragments of earth and to bind the very 

 stones to a more permanent structure. The ground grows 

 richer and richer, until at last the tree springs from the 

 soil, and, where once the ocean and the tempest alone 

 beat on the bare rock, there we see now the lordly monarch 

 of the forest raise its lofty crown, and under its rich 

 foliage shelter bird and beast from the spray and the 

 storm. Soon all is fertile meadow, tangled thicket, and 

 wide-spreading forest. Nor is this always and necessarily 

 a slow, painful progress. The bold navigator Boussin- 

 gault witnessed once, in the south of this continent, one 

 of those stupendous earthquakes which seem to rend the 

 very foundations of our globe. Mountains rose and plains 

 were changed into lakes. Huge masses of porphyry were 



