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PHARMACEUTICAL BOTANY 
4. Endodermis, or innermost layer of cells of the cortex, whose 
radial walls are lenticularly thickened. 
5. Pericambium, of a layer of actively growing meristematic 
cells, which has the power of producing lateral rootlets. 
6. Radial fibro-vascular bundle of five xylem arms alternating 
with as many phloem patches. Note the narrow spiral tracheae in 
the xylem patches. 
en 
Fig. 61. —Photomicrograph of a transverse section of a California Privet root 
of primary growth showing epidermis ( e ); hypodermis ( h ); cortex (c); endodermis 
{en)\ pericambium ( p)\ a xylem arm of the radial bundle (/) and pith (m). 
The section you have just studied illustrated in general the appear¬ 
ance of any Dicotyl root of^ primary growth. 
B. Mount permanently another T. S. 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 and 
open looking endodermis; then pericambium; next, a central patch 
of xylem showing a faint pentarch relation. Pushed out are five 
