90 . III. DIST. CHAR. Prototype. 



Wood is found in every state of mineralization, 

 from the complete petrifaction to that, in which the 

 original substance remains almost unchanged. It oc- 

 curs mostly in alluvial tracts and other modern strata ; 

 also in water ; sometimes in veins and fissures ; very 

 rarely in the less ancient of the secondary strata ; 

 but never in the more ancient (v. SoiL.)f 



The other vegetable substances, which preserve 

 their form in reliquia, of course are frequently 

 found, where the remains of the external parts of 

 vegetables are also common i. e. in the argillace- 

 ous strata of less ancient tracts productive of coal. 

 -(v.59.) 



b. 68. THE EXTERNAL PARTS OF* VEGETABLES 

 (Paries vcgctabilium extern. ) may be divided into 

 the root, trunk or stem, leaves, fulcres, and fructifi- 

 cation. The root (radix) is the part which 

 nourishes the plant, and from which the trunk or 



t At least, never as a constituent, or an imbedded part, of 

 such strata. 



The most singular situation in which petrified wood has been 

 found, is that in New South Wales, described by Mr. Collins as 

 a small, sandy tract, a considerable height above the level of the 

 sea, covered with the scattered, broken branches of dead trees^ 

 and what appear to have been their stumps and roots, still sticking 

 in the ground, but changed to a brittle kind of calcareous stone. 



The sandy deserts of Egypt, and of some other countries, also 

 afford petrified wood, which seems to have been the remains of 

 trees, once growing in those situations. 



