STRUCTURE OF THE STEM 



91 



(8) Thin longitudinal radial sections of sycamore, of sassafras, 

 maple, or box-elder wood. 



(9) Thin sections of elder pith, sunflower-stem pith, or of so-called 

 Japanese " rice-paper." 



104. Names of the Cells of Bark, Wood, and Pith. No 

 two varieties of stems will be found to consist of just the 



FIG. 59. .4, B, C, 

 D, Isolated Wood- 

 Cells and Bast- 

 Cells of Linden. 



A, B, wood fibers ; C, 

 piece of a vessel; 

 Z>, bast fiber; E, a 

 partitioned, woody 

 fiber from Euro- 

 pean ivy. (Much 

 magnified.) 



FIG. 60. Part of Cross-Section of Stem of Flax. 

 (Much magnified.) 



e, epidermis ; b, hard bast ; s, sieve-cells ; w, wood. 



same kinds of cells, present in the same 

 proportions, but it is easy to refer to illus- 

 trations which will serve to identify the 

 kinds of cells found in the studies of the 

 preceding section. They are : 



(1) 



Cork-cells of the epidermis (e.g., flax, 

 Fig. 60, e). 



(2) Cells of the green bark (e.g., flax, Fig. 60), 



between b and e. 



(3) Hard bast (Fig. 60). 



(4) Soft bast (e.g., flax, Fig. 60, s, for the cross-section and (very 

 greatly magnified) Figs. 63, 64, for the lengthwise section). 1 



1 The sieve-tubes shown in these figures are only one of several kinds of 

 cell found in soft bast, but they are the most peculiar and characteristic ones. 

 (See Strasburger, Noll, S,chenk, and Schimper's Text-Book, pp. 102-104.) 



