36 THE VEGETATIVE FUNCTIONS OF PLANTS 



converge at the base of the blade (Fig. 22). They may be 

 traced from this point, through the petiole, into the 

 branch. The veins are composed of fibers and vessels, 



FIG. 28. Horse-chestnut (Aesculus Hippocastanum). Is, leaf-scar, 

 showing scars of seven nbro-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 



