STRUCTURE OF II1<]RBACK()US DIC()T^'LJ<]IX)N()US .STI':MS 193 



* i h 



A f, ^ V s a 



Fig. 172. — Diagrams of highly magnified sections of an Alfalfa stem. 

 A, both cross sectional and lengthwise views of the tissues near the tip of 

 the stem, a, epidermis; I, colhnichyina; e, chlorcnchyma of the cortex; s, 

 starch sheath; i, pericycle; 6, bast fibers; /, conductive portion of the phloem 

 containing the sieve tubes and companion cells; c, cambium; x, xylem; and 

 p, pith; V, vascular bundle. B, section farther from the tip, showing cambium 

 ring and the closing together of the bundles. Lettering as above. 



