GENERAL NATURE OF PLANTS. \) 



Woody Fibre is what causes stiffness and 

 tenacity in certain parts of plants ; hence it is 

 found in the veins of leaves, and in bark, and 

 it constitutes the principal part of the wood. 



The most remarkable form of vascular tissue 

 is the Spiral vessel, which has the power of 

 unrolling with elasticity when stretched. 



Other kinds of vascular tissue are incapable 

 of unrolling, but break when stretched. 



Spiral vessels are not found in the wood or 

 bark, and rarely in the roots of plants. 



Vascular tissue of other kinds is confined to 

 the root, stem, veins of leaves, petals, and other 

 parts composed of leaves. It is not found in 

 bark. 



The common office of the tissue is to convey 

 fluid or air, and to act as the receptacle of 

 secretions. 



The cells of Cellular tissue convey fluids in 

 all directions through their sides, and absorb 

 with great rapidity ; when placed in contact 

 with cells of the same species they join together 

 and adhere — as is exemplified in budding and 

 grafting — the cells adhere, then form Woody 

 fibre — but cells of different or widely related 

 species will not form a junction. 



This is the operation of grafting or budding, 



