328 THE BIOLOGY OF THE PLANT 



5. The root. — Make transverse sections of a large 

 root and examine with the low power. "What is 

 the outline of the section? "What is its color? 

 Do you find the tissues arranged in the same man- 

 ner as in the rhizome ? If not, what are the dif- 

 ferences ? How many vascular bundles are pres- 

 ent ? Notice the root-liairs. Examine with the 

 high power. "What tissues are lacking ? Do you 

 find that the vascular bundles of the roots have 

 the same general structure as those of the rhizome ? 

 Have they the same shape ? Make a diagram of 

 the arrangement of the tissues as seen in this sec- 

 tion. "What is the shape of the root-hairs ? "What 

 is their color ? From what tissue do they grow ? 

 "What is their structure ? Contents ? Compare 

 those found on a large root with those near the 

 tip of one of the smallest rootlets. "What differ- 

 ences do you discover ? Draw several root-hairs. 

 Examine a section showing a surface view of the 

 epidermis, and note the shape and arrangement of 

 the cells and of the root-hairs. Draw. 



Study longitudinal sections and compare them 

 with the transverse and with longitudinal sections 

 of the rhizome. Note particularly the arrange- 

 ment of tissues at the places where rootlets are 

 given off. Draw. 



Cut off the tip of a young root about a half- 

 inch from the end, hold it between two pieces of 

 pith, and cut it into very thin longitudinal sec- 

 tions. Examine these under the low power for the 

 section which passes through the middle of the 

 root and contains the apical cell, which hes a 

 short distance back from the extreme tip of the 

 root. Mount this section in a drop of dilute glyc- 



