1 9 o THE PRINCIPAL SPECIES OF WOOD. 



limited to the neighborhoods in which such trees flourish, but 

 it is probable that the Bamboo can be much more generally 

 employed. Palmwood shrinks generally in drying, principally 

 in the pith-like tissue that surrounds the fibres. These fibres 

 are then closer together than in fresh wood. Palm apparently 

 repels the teredo in many positions. Teredoes are not " worms " 

 but true mollusks. They line their tunnels with calcareous de- 

 posits, along the smooth surfaces of which they can glide, ex- 

 panding or contracting at will. This lining, which is distinct 

 from the boring shell, is preferably, if not always, deposited 

 upon solid wood, cracks and other imperfections being normally 

 avoided. Boards nailed over woodwork afford perfection dur- 

 ing their own existence, because the teredo will not willingly 

 cross the lines of separation. Some think that this explains 

 why Palm wood often remains uninjured in localities where the 

 hardest of hard woods easily fail. Palm trees are cultivated at 

 Southern coast resorts, where they add greatly to the beauty 

 and novelty of the landscape. The Washington or Fanleaf 

 Palm is popular in Southern California. The Royal Palm 

 (Oreodoxa regia} is native in Florida, but is best developed in 

 Central America and the West Indies; its wood is hard and 

 heavy, with large, dark, fibre-bundles, contrasting sharply with 

 their surrounding tissue, as shown in the lower picture of plate 



34- 



The Endogens include numerous families and many thou- 

 sand species.* The grasses, including wheat, rye, and Indian 

 corn at the North and sugar-cane and bamboo at the South, 

 belong to this group. Most Endogens are herbs; compara- 

 tively few furnish material for structural purposes. The Palms, 

 including the palmetto, rattans, cane palms, and others, the 

 Yucca, including the Joshua tree, Spanish bayonet, and others, 

 and the Bamboos, representatives of the grasses, are thus use- 

 ful. Endogens are also known as Monocotyledons. 



*Bastin ("College Botany," p. 379) divides into about fifty natural orders dis- 

 tributed among seven divisions. Warming ("Systematic Botany," pp. 277, 278) 

 divides into seven families corresponding with Bastin's seven divisions. A. Gray 

 divides into twenty -one orders or families. Coulter ("Plants," p. 237) divide* 

 into forty families, including twenty thousand species. 



