94 BARK OF PLANE [CH. 



deeper cork-cambiums arise, and the lower parts may 

 form rough, hard, deeply creviced bark, extending in old 

 trees some ten fee't or more up (Fig. 44). 



Fig. 45. Plane: scaly bark (Irv). 



Ring-bark, resulting from deeply situated periderms, 

 is also formed on the Vine, Honeysuckle, Philadelphia, &c. 



A peculiar and very characteristic form of scale-bark is 

 produced by the true Planes (Fig. 45), and to a less marked 



