Fic. 99,—Cross section through a representative portion of a monocotyl root 
of a species of Smilax. (X 70.) ep, epidermis; hy, hypodermis with lignified radial 
and outer walls; co, cortex; par, parenchyma; en, endodermis whose radiatand inner 
walls are thicker and more lignified than the outer walls and which show a V-shaped 
lumen; fc, pericycle; ph, strand of phloem, the end of the leader being on a sieve 
tube; x, xylem; wf, wood fibers in xylem; ¢r, trachea in xylem; m, pith. Note the 
numerous xylem and phloem strands collectively constituting a polyarch radial 
fibrovascular bundle. 
