78 THE ELEMENTS OF VEGETABLE HISTOLOGY 



Plate 30. — A. Arrangement of the Fundamental Tissue Layers in a 

 Root and Stem. 

 1. Dermatogen zone. 2. Periblem zone. 3. Plerom zone. 



B. Arrangement of the Primary Tissues in the Root. 

 1. Epidermis. 2. Hypodermis. 3. Primary Cortex. 4. Endodermis, 5. 

 Xylem bundle. 6. Pith. 7. Phloem bundle. 



