PRATT: CYCLOLOMA ATRIPLICIFOLIUM. 113 



woody cylinder). Corresponding parts lettered as in figs. 2 and 4: n, one of 

 the several active arcs of secondary meristem in the figure which anastomose 

 radially and tangentially with the arcs, in the corresponding ring of secondary 

 arcs, in the region of stem below; o, area of one to six rows of very large pa- 

 renchyma cells of the primary cortex around the stem; p, anomalous zylem 

 zone; q, zone of anomalous tissue, designated as a phloem zone in this article; 

 r, secondary medullary ray; s, anomalous phloem; t, peri cycle cells in outer 

 portion of a zone of anomalous tissue, designated as a phloem zone in this 

 article. X 18. 



PLATE III. 



Fig. 6. Cross section of the stem in region V. (See fig. 29, s".) Cor- 

 responding parts lettered as in fig. 5: u, radial strip of xylem anastomosing 

 from one anomalous xylem zone to another; a, lenticel; b', cork; c', xylem, 

 the cell walls of which are not lignified except those of the tracheae included 

 in the innermost anomalous xylem zone; d', xylem of usual structure in- 

 cluded in the innermost xylem zone; /', bast fiber; g', radial strip of tissue 

 anastomosing from one phloem zone to another. X 9. 



Fig. 7. Cross section of the stem in region I. (See fig. 29, m".) Cor- 

 responding parts lettered as in fig. 2: h', phloem of primary vascular bundle; 

 i', procambium of primary vascular bundle; j', primary xylem of primary 

 vascular bundle; k', cuticle; I', chloroplast. X 225. 



Fig. 8. Cross section of the stem in region II. (See fig. 29, o".) Cor- 

 responding parts lettered as in figs. 2 to 7, inclusive: m', secondary phloem 

 of primary vascular bundle; n', cambial layer of primary vascular bundle; 

 o', secondary xylem of primary vascular bundle; p', intercellular space. X 225. 



PLATE IV. 



Fig. 9. Cross section of the stem in region III. (See fig. 29, p".) Cor- 

 responding parts lettered as in fig. 8: k, parenchyma of primary cortex be- 

 tween coUenchyma of the rib and the starch sheath; q', oil globule; r', gluco- 

 side globule; s', mass of calcium oxalate crystals in a pith cell; t', single crys- 

 tals of calcium oxalate in a pith cell. X 225. 



Fig. 10. Outer portion of cross section of the stem in region IV. (See 

 fig. 29, r".) Corresponding parts lettered as in fig. 8: o, area of one to six 

 rows of very large parenchyma cells of the primary cortex around the stem; 

 p, anomalous xylem zone; q, anomalous phloem zone; r, secondary medullary 

 ray; s, anomalous phloem; t, pericycle cells in the outer area of a zone of 

 anomalous tissue, designated as a phloem zone in this article; u, radial strip 

 of xylem anastomosing from one anomalous xylem zone to another. X 225. 



PLATE V. 



Fig. 11. Inner portion of a cross section of the stem in region IV. (See 

 fig. 29, r".) Corresponding parts lettered as in fig. 8. X 225. 



Fig. 12. Surface view of lengthened epidermal cells of a rib of the stem 

 in region III, showing type and frequency of stomata. X 225. 



Fig. 13. Radial longitudinal section of the epidermis of the stem in 

 region III: k', cuticle. X 225. 



8— Sci. Bui. X. 



