PLATE 55. PINUS GLABRA. Tangential section through the spring wood showing 

 the ordinary rays with terminal tracheids and with the thin-walled paren- 

 chyma all broken out; the interspersal of the tracheids and their general 

 predominance; the structure of the low and rather broad fusiform ray, the 

 thin-walled parenchyma cells of which have been broken out, leaving only a 

 portion of the rt-Mn canal in the central tract together with the terminal 

 tracheids. x 46.8 



