Vascular System of Matonia pectinata . 499 
DIAGRAMS SHOWING THE DIFFERENT STAGES OF PROGRESSIVE COMPLICATION 
BY TRANSVERSE SECTIONS OF CORRESPONDING NODES, INTERNODES, AND 
LEAF-TRACES. [The diagrams represent actual sections X45.] 
( 1 ) The young plants . 
Internode. Node. Leaf-trace. 
Fig. 12. Xylem diagonally lined, Phloem black, Endodermis dotted. 
