FERN 327 



a section with Schulze's solution, and note espe- 

 cially the color assumed by the cell-walls and 

 cell contents of the different tissues. The cell- 

 walls which stain yellow are lignified. Stain 

 another section with acetic acid carmine, and 

 a third with an aqueous solution of hsematoxy- 

 lin. Compare results. Make longitudinal sec- 

 tions. Under the low power note especially the 

 course of the fibro- vascular bundles where they 

 branch to enter the appendages of the rhizome; 

 also the course of the strands of central scleren- 

 chyma. Examine under the high power, and 

 note again the shape of the cells of the various 

 tissues. Examine in the vascular bundles the 

 long, thick-walled elements, the scalariform 

 tracheides, marked with narrow parallel pits. 

 Stain these sections as above and compare with 

 the transverse sections. Draw. 



Carefully remove the bases of the fronds cov- 

 ering the extreme apex of the rhizome, and with 

 a lens examine the extreme papilla-like end, the 

 apical cone or growing point. Make longi- 

 tudinal and transverse sections of the growing 

 point of two or more rhizomes, and look for the 

 triangular apical cells. Study the relation of 

 the apical cell to the surrounding cells. 



Cut thick sections of the rhizome, mount them 

 on a slide in a few drops of Schulze's macerat- 

 ing mixture, and warm the slide over an alcohol 

 lamp. After a few minutes the section will be 

 resolved into its constituent cells, which may 

 then be studied separately. Note particularly 

 the shape and markings of the various elements. 

 Draw. 



