130 THE ELEMENTS OF VEGETABLE HISTOLOGY 



Plate 48. — Fibrovascular Bundles. 



A. Radial type, Sarsaparilla root. 1. Endodermis. 2. Sieve surrounded by 

 bast fibers. .3. Wood fibers surrounding sieve and ducts. 4. Ducts. 



B. Radial Bundle, arrangement of fibrovascular elements. 1. Endodermis. 

 2. Xylem. 3. Phloem. 4. Pith. 



C. Concentric type, Fern rhizome. 1. Endodermal sheath. 2. Seive sur- 

 rounded by small parenchyma. 3. Fibrous tissues. 4. Ducts. 



D. Concentric Bundle, arrangement of fibrovascular elements. 1. Endodermal 

 sheath. 2. Phloem. 3. Xylem. 



