FEEN 329 



erine and study under the high power. Note that 

 the tip of the root is covered by a mass of cells 

 forming the root-cap. "What is its shape as seen 

 in section ? Of what kind of cells is it composed ? 

 What is the shape of the apical cell ? How do you 

 distinguish it from the surrounding cells? How 

 many cells is it from the tip of the growing por- 

 tion? Note the segmental cells. Stain with 

 acetic acid carmine. Try to see that some of the 

 segmental cells go to form the growing portion of 

 the root-cap, while others are added to the root 

 itself. From what part of the apical cell does 

 each arise ? Study the arrangement of the tissue, 

 the meristem, around the apical cell, and note 

 the differentiation that is gradually taking place. 

 Make drawings to illustrate the structure of the 

 tip of the root. Make transverse sections of 

 the root-tip and compare. Draw. Compare the 

 structure of the root-tip with that of the apex 

 of the rhizome. 



c. The fronds. 



1. The rachis. — Make transverse and longitudinal 

 sections of the rachis midway between the low- 

 est pinnse and the ground, and examine under 

 the low power. What is the shape of the sec- 

 tion ? What is its color ? Is the arrangement 

 of the parts like that in the rhizome or that in 

 the root ? Note the trichomes or hairs around 

 the margin of the section. Put on the high pow- 

 er. Do you find the same tissues present as in 

 the rhizome ? What parts of the section contain 

 chlorophyll ? Study the epidermis and compare 

 with that of the rhizome. Do the trichomes 

 originate in the same manner as the root-hairs ? 



