32 
Garden Work 
by the plant from the soil, and pass them on, through the 
root fibres and roots, into the stem and leaves. These 
root hairs are composed of one cell, which is simply a 
greatly elongated cell of the epidermis of the root fibre. 
The walls of these little root hairs are porous, and cling 
very closely to the particles of soil, sucking up the moisture 
and soluble plant foods which surround them. 
If you pull up a young plant carefully, this can easily 
be seen. The particles of soil will be found clinging to the 
root hairs, or, rather, the root hairs cling 
tenaciously to the little soil particles, where 
the band of root hairs is, while the soil falls 
entirely away from the older parts of the 
root, where there are not any root hairs. 
These tiny hairs not only absorb the mois- 
ture and soluble plant food, but they give 
out a weak acid solution which is able to dis- 
solve certain substances in the soil. These 
substances are then absorbed and passed on 
into the plant. The life of these root hairs is very short, 
as is seen by the growth of the root, there being no root 
hairs beyond 3 or 4 in. from the apex of the root. They 
have an enormous amount of work to perform, and must 
therefore always be in the very best condition to carry on 
that work. As the old ones die offi new ones are formed 
nearest the apex, and so the work goes on constantly and 
vigorously. 
We can trace the course of roots on the inside of a new 
flower pot, or if we allow the roots to grow through the 
flower pot on to a piece of white marble, and then, after 
a considerable time, raise the plant, we find there are 
Absorptive Cells 
on Root of Pent- 
stemon 
