of the Anatomy of the Genus Selaginella , Spr. 203 
Figs. 22-23. S. Bakeriana , Bail. 
Fig. 22. Scheme of arrangement of protoxylems ( x io). 
Fig. 23. A trabecula; the dark shading indicates siliceous deposit ( X550). 
Figs. 24-25. S. uncinata , Spr. 
Fig. 24. Scheme of the arrangement of protoxylems ( x 10). 
Fig. 25. I-IV. Stages in the fusion of the steles of branch and chief axis (x 10). 
I. The left-hand figure represents a transverse section of the stele of the branch 
with one dorsal and two marginal protoxylems ; the right-hand figure represents 
a transverse section of the stele of the chief axis with an isolated dorsal cord. In 
II. fusion has taken place between the adjacent marginal protoxylems, with which 
also the dorsal cord of the branch stele has united. In III. the new dorsal cord is 
seen separating from the main xylem-mass preparatory to fusing with the already 
isolated dorsal cord, IV. 
Figs. 26-29. S' Braunii , Bak. 
Fig. 26. Scheme of arrangement of protoxylems ( x 10). 
Fig. 27. Longitudinal section of the inner cortex and pericycle showing the 
reticulate trabecular tissue ( x 350). 
Fig. 28. Transverse section of the creeping axis showing mode of origin of the 
vascular system of the erect shoot and root ( x 20 semi-diagram). 
Fig. 29. The same in longitudinal section ( x 20 semi diagram). 
Fig. 30. S. oregana, Eat. 
Transverse section of the stem, a, sclerotic tissue ; b, parenchymatous cortex ; 
c, c, leaf-traces ; d, stele ( x 60). 
Figs. 31-38. S. spinosa , P.B. 
Fig. 31. Transverse section of the stem at the level a — a in Fig. 32. The stele 
shows a one-layered pericycle, seven isolated patches of sieve-tubes alternate with 
seven protoxylem-groups and separated from the xylem by one to two layers of 
phloem-parenchyma ( x 350). 
Fig. 32. Scheme of the arrangement of the protoxylems. The letterings a — a, 
b — b, c—c, d—d, e — e, f—f, correspond to the diagrammatic transverse sections in 
Figs- 33-38. 
PLATE X. 
Fig. 39. S. spinosa , P.B. 
Transverse section of the trailing stem, a, pericycle ; b, protophloem-like 
elements ; c, phloem-parenchyma ; d, metaxylem surrounding e, protoxylem 
(X550). 
Figs. 40-42. S. GaleoMei, Spr. 
Fig. 40. Course of the steles through an ‘articulation/ and mode of fusion of 
the steles of axis and branch ( x 1 o). 
Fig. 41. Semi-diagrammatic transverse section of the stem between the origin of 
branches, a, hypodermis ; b, general cortex ; c , lacuna ; d, pericycle ; e, phloem ; 
/, protoxylem ; g, metaxylem ( X 50). 
Fig. 42. A trabecula, showing endodermal cell and cluster of chlorophyll-bearing 
parenchyma abutting on the thick- walled cortex ( x 550). 
Fig. 43. S. delicatissuna, A. Br. 
Variations in the mode of fusion of steles of axis and branch ( x 10). 
P 2 
