270 



A TEXT-BOOK OF BOTANY. 



Bast fibers may be isolated by the use of Schulze's macerating 

 fluid (which is prepared by dissolving a few crystals of potassium 

 chlorate in nitric acid) and moderately heating the solution con- 

 taining the material either on a slide or in a test-tube. 



The mechanical tissue consisting of cells resembling bast fibers 

 and occurring in leaves and fruits is usually referred to as 

 stereome. 



Wood fibers or libriforai cells are sclerenchymatous fibers 



Fig. 140. A, C, bast fibers of the bark of Ciyichona snccirubra; R, bast fibers of the 

 bark of Cinchona Ledgeriana; D, stone cells of Cuprea bark {Remijia peduncuiata). — After 

 Oesterle and Tschirch. 



occurring in the wood and are usually associated with the tracheae. 

 They are scarcely to be distinguished from the bast fibers except 

 by their position, and are the strengthening cells of the xylem. 

 While the bast fiber is frequently not lignified, the walls of the 

 wood fibers usually consist of lignocellulose, and usually give 

 quite pronounced color reactions with acid solutions of either 

 phloroglucin or aniline sulphate. Wood fibers are usually more 



