i6 



THE LIFE-HISTORY OF A FERN 



where they ramify and extend upwards to the extreme tips and margins. 

 On the other hand, strands of vascular tissue derived from the leaf-bases 

 extend towards the tips of the roots, and laterally into their branchlets. 

 The Vascular System is thus a connected conducting-system throughout 

 the plant. It is embedded in softer parenchymatous tissues, which serve 



FIG. i. 



Nephrodium Filix-mas, Rich. A, stock in longitudinal section ; v, the apex ; st, the 

 stem; />, the leaf-stalks; b' , one of the still folded leaves ; g, vascular strands. , leaf- 

 stalk bearing at k a bud with root at -w, and several leaves. C, a similar leaf-stalk cut 

 longitudinally, bearing bud, /*, with root, w. D, stock from which the leaves have been 

 cut away to their bases, leaving only those of the terminal bud. The spaces between the 

 leaves are filled with numerous roots, w, w'. E, stock from which the rind has been 

 removed to show the vascular network,^-. F, a mesh of the network enlarged, showing 

 the strands which pass out into the leaves. (After Sachs.) 



various purposes in the different parts : thus in the young root they may 

 be absorbent, or serve to hand on the fluids absorbed to the conducting 

 system : in the stem they may serve the purpose of storage of reserve 

 materials, while in the leaf the parenchyma carries out the function of 

 photosynthesis, together with the passing on of the supply thus acquired 

 to the conducting-system. The parts exposed to the air are covered by 



