PLATE XXI. 



Tangential Sections. Natural Size. 



Fig. 172. 



Cocus, showing Heart-wood 

 and Sap-wood. 



Fig. 173. 



Casuarinrx, showing the ends of the Rays 

 after the removal of the Bark. 



Fig. 174 



Lophira (African Oak), showing the 



coarse prominent pores and the tracery 



caused by the cutting of the rings 



of soft-tissue. 



Flf. 175. 



Sicnocarpus (Nilky O:U, showing the 

 splitting-up and distortion of the Ray*. 



