36 



THE VEGETATIVE FUNCTIONS OF PLANTS 



converge at the ])ase of the blade (P'ig. 22). They may be 

 traced from tl\is point, through the petiole, into the 

 branch. The veins are composed of fibers and vessels, 



Fig. 28. — Horse-chestnut {Aescidus Hippocastanmn). Is, leaf-scar, 

 showing scars of seven fibro-vascular bundles, corresponding, in number, 

 to the seven leaflets of the compound leaf, formerly attached at Is. The 

 leaf is drawn to a smaller scale than the branch. 



closely associated, and are, therefore, called fibro-vascular 

 bundles. A cross-section of the petiole of a horse-chestnut 

 leaf, for example, shows one fibro-vascular bundle for 

 each leaflet of the compound blade (Fig. 28) ; each of the 



