PLATES XXXII & XXXUl—con{i?iued. 



Fig. IX. — X f . Transverse sections of one of the lobes of tlie crown. 

 A at a lower, and B at higher point. 



Pig. X. — X ^^. The area marked (x) in Fig. yiii, a., showing the 

 manner of division of the tissues at the base of the leaf groove. 



Fig. XI. — Natural size. Longitudinal median section of an old plant 

 which died in the Royal Gardens, Kew. 



Fig. XII. — X f. Section from the stem of the above plant in the plane 

 of the leaf continued into the stem. This shows the intercalation of fresh 

 bundles {ini. bun.) between the older bundles of the leaf trace (cf. text). 

 Figure semi-diagrammatic, but the bundles are drawn true to nature. 

 A, B, c, refer to text, and Fig. xi. 



Fig. xiii. — (1 — 4) x \''. Progressive stages of development of the 

 male branches, as seen in longitudinal sections perpendicular to the surface 

 of the inner lip of the leaf groove. (5) = apical view of the young 

 branch ; here the apical cone is covered by irregular flaps, developed from 

 the margin of the depression. 



Fig. XIV. — Natural size. View of inner lip of the leaf groove of an old 

 plant with three male branches fully developed, and several still young. 



Fig. XV. — Longitudinal section of the base of a male branch, showing 

 its connection with the lip of the leaf groove. 



Fig. XVI. — x ^^. Part of a longitudinal section at the base of the leaf. 

 The tissue is still undergoing division, but one cell has ceased to divide, 

 and is beginning to develop as a spicular cell. The crystals and lignified 

 wall not yet formed. 



Fig. XVII. — x ^S. End of a young spicular cell (crystals and lignified 

 wall already formed) from close below the surface of the lip of the leaf 

 groove. This shows how in growth the cell follows the intercellular spaces. 



Fig. XVIII. — x J-^. Young spicular cell cut obliquely, showing single 

 nucleus and pitted wall. 



Fig. XIX. — x ^^. Part of wall of a young spicular cell in longitudinal 

 section, showing how the protoplasm extends as plugs into tiie pits. 



Fig. XX. — x J-p. Part of a transverse section of a root, treated with 

 HNO3 to dissolve the cystals. Side by side are seen spicular cells in 

 various stages of development, cut transversely. 



Fig. XXI. — x ^-. Longitudinal section of soft bast in tlie root, 

 showing sieve tubes, with the sjeve plates on the oblique walls. 



