198 PHARMACEUTICAL BOTANY 
each of its faces. It will be noted that more secondary xylem is 
added than secondary phloem. The result of the activity of the 
cambium ring is the deepening of the primary bundles and the 
x 
5 *lloge, pce 
Brey Cambium 
Ylem fro 
S iM the Camby 
a 
Prog, a th 
4 a o4 
-& 4 
Heal wy “ ‘ 
Cj os s 
5 ce & U 
- ‘a 
é E 
a co 
“Ho 
| 7 iz. [ 
cS F = | 
. caf LI 
H : a 1 
- | 1 | me 
- a Lier 
en elb q = | 
i : 
aed & 
s-1 LE : re 
gente 2s 
Fic. 128.—Diagram similar to the preceding but representing a later stage and 
showing the tissues formed by the cambium. (From Stevens.) 
primary medullary rays, the appearance of new or secondary 
bundles (which are smaller than the primary bundles) in the 
primary medullary rays and the appearance of narrow secondary 
medullary rays between the secondary bundles as well as inside 
