148 



Practical Plant Biology. 



foliage-leaves retain their fresh green colour for one season 

 and then wither back, leaving only their base attached to the 

 stem. On the edge of the cut surface of the longitudinally split 

 stem we can make out the attachment of many of these older 

 leaves. 



On the cut surface fibrous tracts of tissue are visible here and 

 there. These tracts are cord-like and are found in the stem close 

 to the bases of the leaves. Similar but finer cords enter the stem 

 from the leaves. These are the conducting tracts or vascular 



FIG. 33. Aspidium filix-mas, transverse section of rhizome, x 10. a, con- 

 ducting tracts or vascular bundles forming the net-work in the stem; 

 b, small conducting tract given off from the net-work and running out 

 into the leaves ; /, fundamental tissue ; r, conducting tract entering a 

 root. 



bundles which transmit water and other materials through the 

 plant. They form a tubular net-work in the stem, close to the 

 bases of the leaves. Each mesh of the net-work which is ir- 

 regularly rhomboidal in outline corresponds to a leaf base. Thread- 

 like tracts are given off from the inside of the mesh, which, 

 converging slightly towards one another, then turn upwards and 

 pass out into the corresponding leaf. This net- work of con- 

 ducting tracts is embedded in the soft white slimy substance 

 of the stem which is called the fundamental tissue. The roots also 



