1 16 MAIDEN-HAIR FERN. 



i. That the walls of these vessels present many 

 narrow thin spaces, looking like slits placed 

 transversely. 



ii. That these thin spaces do not extend entire- 

 ly across the face of a vessel. 



iii. Find a place where the contiguous walls of 

 two vessels have been cut through by the 

 razor and observe the beaded appearance of 

 the walls. Each "bead " corresponds to the 

 thick part of the wall and the intervals to the 

 thin places. 



Isolate some scalariform vessels by boiling a rather thick 

 longitudinal section for a few seconds in potassic chlorate 

 solution. Mount in water and examine with a high power 8 



iv. The shape and markings. Draw. 

 d. Draw the fibro-vascular bundle with a portion of 

 the bundle-sheath. 



19. The trichomes, in the form of scales. Mount scales of 

 various shapes under the same cover, and observe 



a. The shapes and arrangement of the cells, espec- 

 ially at the apices of the scales. 



b. Draw a scale. . . 



B. THE ROOT. Cut a transverse section of one of the 

 larger roots, examine with a high power, and note 



1. At the edge of the section (if perfect) the epidermis? of 

 irregular thick-walled cells, not differing much from 



2. The underlying brown parenchyma, which gradually 

 merges into 



8 If the vessels do not separate in mounting, press gently on the cover- 

 glass with a little sidewise push. 



9 So called here because of its position ; not necessarily homologous 

 with the epidermis of the stem. 



