172 PHARMACEUTICAL BOTANY 
The section you have just studied illustrated in general the 
appearance of any Dicotyl root of primary growth. 
B. Mount permanently another cross section cut through the 
same root a short distance above the first. 
Note that this is somewhat larger in diameter. Observe the 
root hairs starting from the epidermis; a broad cortex; a large clear 
pe 
development. More secondary xylem has been laid down on the inner face of 
the cambium and there has been a slight increase in the secondary phloem. ¢f, 
epidermis; h, hypodermis; fc, primary cortex; ck, cork; pn, phellogen or cork cam- 
bium; sc, secondary cortex; pp, protophloem; sf, secondary phloem; ¢c, cambium; sx, 
secondary xylem; px, protoxylem. 
and open looking endodermis; then pericambium; next, a central 
patch of xylem showing a faint pentarch relation. Pushed out are 
five phloem tracts. Each of these is composed of a mass of 
protophieom (first formed phloem). On the inner face of each 
phloem mass may be seen intrafascicular cambium. At the outer 
end of each xylem tract there has been cut off a patch of fine 
cambial cells (interfascicular cambium) which becomes joined to the 
intrafascicular cambium to develop secondary phloem on the outer 
surface and secondary xylem on the inner face. 
