
THE ROOT aya 
manufactured food which comes down the stem from the leaves 
can reach the smaller roots only by passing through the larger 
ones. Thus it will be seen that roots, like stems, have the inci- 
dental functions of conducting food and water. The cells in 
which such conduction 
is carried on are alike in 
roots and stems. Roots, 
like stems, also serve for 
the storage of food and are 
sometimes greatly thick- 
ened with storage tissue 
(Fig. 180). 
GROWTH OF ROOTS 
Rootcap. Roots are like 
stems in having at the tip 
a growing region, called 
the growing point. As the 

growing point Is com- i) 
posed of meristematic cells h 
which are soft and have NN 
thin walls, obviously it MW 
must be protected in some FicG.180. Radish with greatly thickened 
way; otherwise the meri- storage root. (x 4) 
stematic cells would be 
destroyed while being pushed through the soil. This protective 
function is performed by a cap-shaped structure, the rootcap, 
which covers the growing point (Figs. 181, 183). The rooteap 
and the tip of the root are joined at the growing point, which 
consists of a small group of meristematic cells (Fig. 182). The 
outer part of the growing point produces cells that are added 
to the rootcap, while the inner portion forms cells which increase 
the length of the root. 
The rootcap not only protects the growing point of the root 
but also serves as a boring point. It is especially fitted for 
