5 



THE VEGETATIVE FUNCTIONS OF PLANTS 



The tip of the root is covered by a root-cap (Fig. 37), 

 composed of cells that serve to protect the delicate tip as 

 it grows through the soil. In some cases, as in the 



FIG. 36. Germinating seeds of white mustard, showing development of 



root-hairs. 



water-hyacinth (Figs. 38 and 39), the root-cap is so well 

 developed that it may be easily seen with the naked eye, 

 and quite readily removed and replaced. Root-hairs are 

 never found on the region covered by the root-cap. 



