18 
LABORATORY EXERCISES 
growth take place? Locate the zone of root hairs ” with reference 
to the tip. (See Waggoner, Figs. 43, 45, and 46.) Why is it of 
great advantage to the plant that the root should grow at this 
point rather than farther back from the tip? Why does soil ad¬ 
here to young roots? 
Make a drawing of one of the roots. Show the ‘‘ zone of root 
hairs.’’ 
II. Soil water is taken into the plant through the root haiis. 
(The process of osmosis by which this transfer takes place will be 
discussed later. See Exercise 23.) The walls of the root hairs are 
thin. What is the advantage of this fact? Why does a plant wilt 
when it is transplanted? Why do we usually take up soil with a 
plant which is to be transplanted? During plant growth, how 
does the position of the zone of root hairs ” change in relation to 
the layers of soil? Of what advantage to the plant is this change? 
EXERCISE 19 
TRANSPLANTING SHRUBS AND TREES 
With your observations of root hairs in the laboratory and your 
study of the text (see Waggoner, Page 87) as a basis, make 
plans for transplanting some wild shrubs or trees from a neighbor¬ 
ing woodland to your school grounds. Then, if possible, put your 
plans into operation. Note carefully the soil and drainage condi¬ 
tions of the school grounds and select only those plants which grow 
naturally under similar conditions. Why are these precautions 
taken? In selecting the location for planting, take into considera¬ 
tion the size which the plant may later attain, the purpose which 
it is to serve in the school grounds — shade, decorative effect, 
shelter and food for birds, etc. — and any previous planting which 
has been made. 
Write to the American Tree Association, 1214 Sixteenth Street 
N. W., Washington, D. C., sending two cents return postage, and 
receive information regarding the planting of trees and their 
registration with the Association. 
