12 



WOOD AXD FOREST. 



Not all of the "conifers'' bear cones. For example, the juniper 



bears a berry. The ginko, Fig. 2, tho classed among the "conifers," 



the "evergreens,'" and the "needle-leaf trees, bears no cones, has 



broad leaves and is deciduous. It has an especial interest as being 



the sole survivor of many species which grew 



abunilantly in the carboniferous age. 



Also, the terms used by lumbermen, "hard 

 woods'' for broad-leaved trees and "soft woods'' 

 for conifers, are still less exact, for the wood 

 of some broad-leaved trees, as bass and poplar, 

 is much softer than that of some conifers, as 

 Georgia pine and lignum vitae. 



Another classification commonly made is 



that of "endogens" (inside growers) including 



bamboos, palms, etc., and exogens (outside 



growers) which wordd include both conifers and 



broad-leaved trees. 



One reason why so many classifications have come into use is 



that none of them is cpiite accurate. A better one will be explained 



later. See p. 23. 



As in the study of all woods three sections are made, it is well 

 at the outset to understand clearly what these are. 



The sections of a tree made for its study are (Fig. 3) : 



(1) Transverse, a plane at right angles to the organic axis. 



(2) Eadial, a longitudinal plane, including the organic axis. 



Fig. 2. Ginko Leaf. 



A.. 



A, B, C, D, Transverse Section. 



B, D, E, F, Radial Section. 



G, H, I, J, Tang-ential Section. 



A, H, C, Transverse Section. 



A, li, D. E, Radial Section. 



B, C, li, F, Tangential Section. 



