MACROSCOPIC STRUCTURE. 



abundant in tbe spring-wood ; 

 they are also larger in the 

 spring-wood, The summer- 

 wood is somewhat darker 

 than the spring-wood. Hays 

 scarcely visible. 



Radial Section. - The 

 vessels in the spring-wood 

 form large grooves, dark 

 brown or nearly black ; light 

 brown in the grey walnut. 

 Hays scarcely visible. 



Tangential Section. The 

 annual rings are, according 

 to the incidence of light, 

 cither bright or dark lines. 

 The vessels as in radial sec- 

 tion; medullary rays invisible. 



Juglans nigra. Sap wood 

 broad ; heartwood reddish- 

 brown. 



Juglans regia. Sapwood 

 broad : heartwood light grey 

 to dark violet. 



Juglans cinerea. Sapwood 

 brown to greyish-brown. 



Fitr. 1 <'. -Type of Walnut-wood 

 (Juglans). 



broad : heartwood light 



H. HjM'cirs of M<ij>l<' (Acer). 

 (America, Asia and Europe.) 



Transverse Section. Spring-wood is pale, summer-wood 

 lark, so thai the annual rings are clearly marked. Tbe 

 vessels arc all very narrow and invisible. The medullary 

 rays are numerous, and with proper light-incidence appear as 

 pale., bright lines. 



Radial Section. Annual rings only fine dark lines. 

 Medullary rays, according to angle of light-incidence, either 

 pale or dark bands, or specks, silky, narrow and very 

 numerous. 



