PROPERTIES OF WOOD. 



is gradual, and the latter is limited to a narrow zone. 

 The sapwood is hroad, the heartwood pale reddish-brown, 



becoming darker on seam- 



x\ ing. Narrow-zoned Wey- 



Xv < ; A .x mouth pine wood taken from 



N^ the outer zones of old trees 



is not distinguishable from 



y^SS Cembran pinewood, even 



X^i microscopic observation fails 



S\ to separate them. 



32. Woods of Silver-fir, 

 Abies ; of Hemlock- spruce, 

 Tsuga ; of Taxodiniae, 

 Sequoia, Cryptomcria, and 

 Taxodium ; oj Cedars, 

 Cedrus.* 



The genus Abies includes 

 all silver-firs in America, 

 Asia and Europe ; Tsuga is 

 represented by seven species 

 only in America and Asia ; 

 Sequoia and Taxodium in 

 America only ; Cryptomeria 

 in Asia ; Cedrus by three 

 species or varieties in Africa 

 and Asia. 



As there are no resin-ducts,* only differences in colour and 

 scent apparently are available in the identification of these 



* [The wood of Deodar {Ctdrus Libani, var. Deodara) is moderately hard, 

 strongly scented, and very oily. The annual rings are distinct, owing to the 

 darker summer-wood. The medullary rays are fine, unequal, and irregular, 

 fairly numerous, and show as a silver-grain on the radial section. The resin- 

 ducts are contiguous and arranged in concentric rows of single ducts close to 

 the borders of the annual zones of wood. They are absent from some of these 

 zones, and in the specimen before me appear in alternate zones only. More 

 knowledge is required about these ducts in deodar- wood, and whether they 

 occur also in the cedars of Lebanon and of the Atlas Mountains. Their 

 presence in deodar-wood was reported in Gamble's " Indian Timbers." first 

 edition (1881), but was omitted in the second edition of this book (lM.)i>). Other 

 authorities state that ee<larv\oo<l contains no duels. Tr. 



B X './ 



Fig. 24. -Type of Cembran Pinewood 

 (Pin-ug, group Cewbra), and of Wey- 

 mouth pinewood (Pi/nts, group Strulus}. 

 A Cembran pine. B Weymouth pine. 



