12 TIMBER. 



poplar, etc.), and to an inferior extent by the nionocotyledonous (with 

 one seed leaf), palms, yuccas, and their allies, which last are confined 

 to the most southern parts of the country. 



Broad-leaved trees are also known as deciduous trees, although 

 especially in warm countries, many of them are evergreen, 1 while the 

 conifers are commonly termed "evergreens," although the larch, bald 

 cypress, and others shed their leaves every fall, and even the names 

 "broad-leaved" and "coniferous," though perhaps the most satisfac- 

 tory, are not at all exact, for the conifer ginkgo has broad leaves and 

 bears no cones. 



In the lumber trade, the woods of broad-leaved trees are known as 

 "hardwoods," though poplar is as soft as pine, and the coniferous 

 woods are " soft woods," notwithstanding that yew ranks high in hard- 

 ness even when compared to " hardwoods." 



Both in the number of different kinds of trees or species and still 

 more in the importance of their product the conifers and broad-leaved 

 trees far excel the palms and their relatives. 



In the maimer of growth both conifers and broad-leaved trees behave 

 alike, adding each year a new layer of wood which covers the old wood 

 in all parts of the stem and limbs. Thus the trunk continues to grow 

 in thickness throughout the life of the tree by additions (annual 

 rings) which in temperate climates are, barring accidents, accurate 

 records of the tree. With the palms and their relatives the stem 

 remains generally of the same diameter, the tree of a hundred years 

 being as thick as it was at ten years, the growth of these being only at 

 the top. Even where a peripheral increase takes place, as in the yuc- 

 cas, the wood is not laid on in well-defined layers ; the structure remains 

 irregular throughout. 



Though alike in their manner of growth, and therefore similar in 

 their general make-up, conifers and broad-leaved trees differ markedly 

 in the details of their structure and the character of their wood. The 

 wood of all conifers is very simple in its structure, the fibers compos- 

 ing the main part of the wood being all alike and their arrangement 

 regular. The wood of broad-leaved trees is complex in structure; it is 

 made up of several different kinds of cells and fibers and lacks the reg- 

 ularity of arrangement so noticeable in the conifers. This difference is 

 so great that in a study of wood structure it is best to consider the 

 two kinds separately. 



WOOD OF CONIFEROUS TREES. 



Examining a smooth cross section or end face of a well-grown log of 

 Georgia pine or Norway pine, we distinguish an envelope of reddish, 

 scaly bark, a small whitish pith at the center, and between these the 

 wood in a great number of concentric rings. 



1 In Ceylon even the cultivated cherry has become an evergreen. 



