282 THE WONDERS OF VEGEGAOION. 



But all these plants have been found in a petrified 

 state in the rocks of the coal formation. There they 

 are preserved for us in the most wonderful museum 

 in the world. It is astonishing sometimes to find 

 that the texture the fibres and the pulp have all 

 preserved their forms unaltered, though the substance 

 itself has entirely disappeared. The Town Hall of 

 Nordhausen, in Germany, contains a staircase of 

 sandstone, each fragment of which clearly indicates 

 that it has been originally of wood. But no example 

 is so remarkable as the forest of petrified trees which 

 Sir James Ross visited in Yan Dieman's Land, al- 

 though it must be borne in mind that this forest be- 

 longs not to the first coal measures, but to the series 

 of Tertiary strata. 



" One of the most marvellous natural curiosities," 

 says this traveller, " which attract geologists to Yan 

 Dieman's Land, is the valley of petrified trees, a great 

 number of which are transformed into the most beau- 

 tiful opal. While the exterior presents a bright, homo- 

 geneous surface, like a pine stripped of its bark, 

 the interior consists of concentric layers, which ap- 

 pear perfectly compact and of the same nature, but 

 which can be easily split up in the direction of their 

 length. These trees are standing upright, and it 

 would seem that they were in full growth when the 

 burning lava overwhelmed them. Some fragments 

 of this wood have been carefully examined, and look- 

 ed so full of life, so absolutely like wood, that only a 

 very careful examination brought the conviction that 

 they were really stone." 



