PLATE LIX 



Fig. i. Log from collection of woods in the Forest-Products Laboratory a speci- 

 men of the material used in this study; S, sap wood; H, heartwood. 



Fig. 2. Specimens of woods showing creosote penetrance in sap and heartwood 

 as affected by tyloses. The three specimens each contain both sapwood and heart- 

 wood. Specimen A. Red oak. Has no tyloses; creosote passed chiefly down the 

 large vessels; note black streaks. Wood substance between vessels little treated; 

 note white streaks. Specimen B. White oak. Has abundant tyloses in sap and 

 heartwood. Creosote penetrated the sapwood only. Thorough absorption obtained 

 in the sapwood substance between the impenetrable, tylose-filled vessels. Speci- 

 men C. Pignut hickory. Has abundant tyloses in sap and heartwood. Creosote 

 penetrated both. Good absorption throughout in the wood substance between the 

 tylose-filled vessels. Compare Plate LI I, figure i, an enlarged view of a portion of 

 this block. 



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