20 



ECONOMIC "WOODS OP THE UNITED STATES 



tapering, but sometimes they are flattened, or forked, or with a 

 saw edge (Fig. 2, C, C), adding to the toughness of the wood. 

 Fibres usually run parallel to one another, but in some woods 

 they exhibit a decided interweaving which produces an irregularly 

 grained wood very difficult to split. 



TABLE II 



Length of Wood Fibres in Dicotyledonous Woods 



Botanical Name 



Average 

 mm. 



Maximum 



mm. 



Minimum 



mm. 



Acer rubrum 



Betula nigra 



Castanea dentata 



Celtis occidentalis 



Fagus americana 



Hicoria alba 



Ilex opaca 



Juglans nigra 



Liquidambar styraciflua 

 Liriodendron tulipifera. 

 Magnolia acuminata. . . 



Nyssa sylvatica 



Platanus occidentalis. . . 

 Populus deltoides 



" grandidentata . 



" heterophylla. . . 



" trichocarpa 



Quercus alba 



" coccinea 



" michauxii 



" rubra 



" virginiana 



Salix nigra 



Tilia americana 



Ulmus americana 



.75 

 1.80 

 1.15 

 1.25 

 1.20 

 1.35 

 1.45 

 1.10 

 1.60 

 1.90 

 1.75 

 1.70 

 1.90 

 1.40 

 1.00 

 1.35 

 1.15 

 1.25 

 1.50 

 1.55 

 1.20 

 1.40 



.85 

 1.15 

 1.50 



1.00 

 2.20 

 1.45 

 1.70 

 1.70 

 1.70 

 2.00 

 1.65 

 2.00 

 2.50 

 2.30 

 2.35 

 2.30 

 2.20 

 1.35 

 1.80 

 1.90 

 1.50 

 2.10 

 1.80 

 1.45 

 1.80 

 .95 

 1.45 

 1.90 



.50 



1.50 



.80 



1.05 



.75 



.90 



1.15 



.65 



1.25 



1.40 



1.00 



1.05 



1.30 



.50 



.65 



1.00 



.50 



1.00 



1.00 



1.10 



.70 



.85 



.45 



.85 



1.15 



References 

 DeBart, A.: Comparative Anatomy, pp. 481-483. 

 Solereder, H.: Anatomy of the Dicotyledons, Vol. II, pp. 1141-1143. 

 Gregory, E. L.: Pores of the Libriform Tissue, Bull Torrey Bot. Club, 



Vol. XIII, 1886, pp. 197-204; 233-244. 

 Anonymous: Length of Wood Fibers in Broadleaf Woods, Sc. American 



Sup., Sept. 30, 1911, p. 211. 

 Sanio, Carl: Bot. Zeitung, Vol. XXI, No. 13, 1863, pp. 89-111. 



