282 GEOLOGY OF THE ISLE OF WIGHT. 



destruction. Trunks and branches, from a few 

 inches to three feet in diameter, and many feet in 

 length, are in general to be seen lying on the shore 

 between high and low water mark ; and in these 

 specimens the texture of the wood, and the annular 

 lines of growth on the waterworn transverse frac- 

 tures, are strongly defined. On a late visit there 

 were two stems which could be traced to a length 

 of twenty feet ; and they were of such a mag- 

 nitude as to indicate the height of the trees when 

 living at from forty to fifty feet. Many stems 

 are concealed and protected by the fuci, corallines, 

 and zoophytes, which here thrive luxuriantly, and 

 occupy the place of the lichens and other para- 

 sitical plants, with which the now petrified trees 

 were doubtless invested when flourishing in their 

 native forests, and affording shelter to the Iguan- 

 odon and other gigantic reptiles. 



Structure of the Fossil wood. — These fossil 

 trees are calcareous, not siliceous like those of 

 Portland. The wood is more or less traversed by 

 veins and filaments of pyrites, which impart 

 a beautiful appearance to polished specimens 

 of the steins. Slices rendered transparent by 

 Canada balsam, exhibit under the microscope, in 

 the transverse sections, the cellular tissue as a 

 reticulation of polygonal meshes; and in the radial, 



