Ash (Fraxinus). Summer pores not much clustered, but single or 

 more or less connected in fine, broken, wary lines ; pith rays minute, 

 hardly visible to the naked eye except on radial section ; heart-wood red- 

 dish; sap-wood pale; wood not yellow, but very heavy and hard. 



Sassaftas (Sassafras opficinale) . Summer pores not much clus- 

 tered, but more or less connected in short oblique lines ; pith rays barely 

 visible to naked eye except on radial section ; heart-wood brownish ; sap- 

 wood pale ; both with characteristic odor when freshly cut, light and soft. 



D. Summer pores isolated and scattered irregularly, sometimes but little 

 smaller than the spring pores ; the latter in some cases forming 

 but an imperfect zone {scatter-pored') . 



Hickory (Carta). Summer pores much smaller and fewer than the 

 spring pores ; the latter forming a well-marked zone ; pith rays very fine, 

 connected by still finer cross-lines so as to form a distinct network ; heart- 

 wood and outer summer part even of the sap-wood with a tinge of red. 



Walnut ( JuGLANs) . Summer pores not much smaller than the spring 

 pores ; the latter seldom forming a well-marked zone ; pith rays, fine, 

 connected by cross-lines which are sometimes rather obscure and irregu- 

 lar; heart-wood brownish; sap-wood pale; summer-wood not clearly 

 distinguished from spring- wood by difference of color. 



n. WITH PORES WHICH AEE ALL OF ABOUT THE 

 SAME SIZE (EQUAL-PORED). 



A. Pores comparatively large, distinctly visible to the naked eye on 



longitudinal sections (large-pored). 



1, Pith rays rnore or less conspicuous, especially on the radial section, 



often colored peculiarly (strong-rayed) . 



Cherry (Prunus serotina) . Sap-wood whitish, strongly contrasted 

 with the heart-wood which is reddish, often tinged with wine color ; wood 

 hard. 



Slaple (Acer). Sap-wood whitish or rosy, not strongly contrasted 

 with the heart-wood which is pale reddish or brownish; wood hard. 



Tulip whitewood (Liriodendron Tulipifeka) . Sap-wood whitish, 

 well contrasted with heart-wood which is yellowish, often greenish or 

 violet tinged ; wood rather soft. 



2. Pith rays inconspicuous, never distinctively colored (weak-rayed). 



Poplar (PopULUs). Wood very soft, commonly with a fine satiny 

 luster, especially on radial section; sap-wood broad, whitish; heart-wood 

 greyish, reddish, yellowish, orange or brownish, often streaked. 



Birch (Betula). Wood hard, somewhat lustrous, sap-wood broad, 

 pale, often rosy; heart-wood reddish. 



