156 Mr Bowman on (he Fossil Trees found on the Line of 



sure. It has a singular concave depression along its whole 

 length on the north side, as though a cylindrical column, or 

 parasitical creeper, had been pressed against the trunk while 

 growing. 



Such, very briefly, are the prominent features of these ex- 

 traordinary fossils, a mere sight of which is sufficient to con- 

 vince the intelligent observer that they must have grown upon 

 the spots they still occupy, and could not have been of that 

 soft succulent nature which many of the gigantic vegetables 

 of the carboniferous epoch undoubtedly were. Their general 

 character, size, and robust habit, are precisely those of an aged 

 tree of the present day, the trunks much widening below, 

 where the enormous roots strike off, and appearing as the 

 remnants of a forest of blasted and lifeless oaks, whose trunks 

 and roots alone survive. Their enormous roots were mani- 

 festly adapted for taking firm hold of the soil, and, in conjunc- 

 tion with the swollen base of the trunks, to support a solid 

 hard-wooded tree of large dimensions and spreading top, and 

 to enable it to resist violent storms. 



From the evidence, therefore, which these fine specimens 

 present, I shall endeavour to shew, in opposition to the gene- 

 ral opinion of ^geologists, 



1^^, That they, and of course many others of the carboni- 

 ferous epoch, were solid, hard-wooded, or timber trees. 



2d, That they originally grew and died upon the identical 

 spots where they are now found interred, and have not been 

 drifted from distant lands. 



od. That they have become hollow owing to the* decay of 

 their wood by natural causes, and have been subsequently 

 filled with foreign inorganic matter, precipitated as a sedi- 

 ment from water. 



1^/, That they were solid timber trees. It is well known 

 that all modern dicotyledonous trees in temperate climates in- 

 crease in thickness by means of a new layer of wood formed 

 annually between the bark and the alburnum. The furrows 

 in the bark and the swollen base of the trunk are due to the 

 expansion caused by this increase. So is the apparent ten- 

 dency of the main roQts of old trees to rise above the surface of 



