﻿Grossenbacher: Medullary spots and their a 



Fig. 12. Medullary spot shown only by the presence of irregular li 



11 marked differences between boundary lines on the bark and pith sides of the 



Fig. 15. Medullary spot showing incurving of bounding rays at right and left, 

 well as a bulging of the ray at right. 

 Fig. 16. Medullary spot showing incurving of rays and of other radial rows. 



