POLYPODIUM VULGARE 71 



than the "inner sclerenchyma. How do 

 they appear when a section is held to the 

 light? 



(/) Identify all the areas referred to above '(e, 1-5) 

 in a longitudinal section of the rhizome. 



(g) At home, write a well-worded description of 

 your observations under e and /. 



(ti) Make a diagram, 10 cm. in longest diameter, 

 showing carefully the outline of the rhizome as 

 seen in cross-section, and all the tissue-regions 

 identified. Label each region, and underneath 

 your drawing indicate the amount of enlarge- 

 ment. 



(i) Underneath the first diagram make a second 

 one, of the same enlargement, showing the rela- 

 tion of the tissues of thfc rhizome as seen in 

 longitudinal section. 



The roots. 



(a) Describe the location, form, length, diameter, 

 branching, relative number, and relation to 

 each other (i.e., close together or not; inter- 

 woven or not) of the roots. Draw. 



The leaves. 



(a) On what surface of the rhizome are the leaves 

 borne? 



(b) Note their differentiation into stem-like part, 

 the petiole, and expanded portion, the blade. 



(c) What is the color of the leaf? Describe and 

 suggest a probable reason for any differences in 

 color. 



(d) Is the petiole glabrous (smooth, without hairs), 

 or pubescent (hairy) ? 



(e) Is the blade entire, or divided into pinnae? If 

 the latter, do the clefts between the pinnae ex- 



