496 Boodle.—Anatomy of the Hymenophyllaceae . 
Fig. 19. Transverse section of rhizome of smaller plant of H. cruentum. Lower 
xylem-band probably absent, x 390. 
Fig. 20. Transverse section of petiole of II. cruentu 77 i. s.t. is a sieve-tube in 
contact with a tracheide. x 390. 
Fig. 21. Transverse section of stele of rhizome of small plant of II. dilatatu 77 i. 
x 165. 
Fig. 22. Photograph of transverse section of rhizome of Tricho 77 ia 7 ies 7 'enifor 7 ne. 
x 75- 
Fig. 23. Transverse section of young rhizome of T. renifor 7 ne. x 260. 
Fig. 24. Photograph of transverse section of rhizome of T. radicaTis. x 75. 
Fig. 25. Transverse section of young petiole of T. radica 7 is. x 200. 
PLATE XXVII. 
Fig. 26. Diagram of transverse section of petiolar bundle of T. radica, 7 is. As in 
previous diagrams, the phloem is indicated by broken lines, the protoxylem by dots, 
and the metaxylem by cross-hatching, x 95. 
Fig. 27. Diagram of transverse section of base of petiolar bundle of T. radicans. 
The xylem here forms a continuous ring, x 95. 
Fig. 28. Longitudinal section of node of T. radicans. br ., stele of axillary 
branch ; pet ., bundle of petiole, x about 6. 
Fig. 29. Diagram of transverse section of node of T. radicans. l.t., leaf-trace ; 
br., axillary branch; s., stele of rhizome ; protoxylem, &c. indicated as before, 
x about 40. 
Fig. 30. Diagram of same node lower down. Leaf-trace and stele of axillary 
branch fused, x about 40. 
Fig. 31. Diagram of same node. Fusion of leaf-trace and stele of rhizome 
beginning, x about 40. 
Fig. 32. Diagram of same node. Fusion complete, except that the two proto- 
xylems remain distinct, x about 40. 
Fig. 33. Diagram of transverse section of node of T. Prieurii. In this and the 
three succeeding diagrams the sclerenchyma-groups are shaded ; x, x ', x" are the 
xylems of stele of rhizome, of first leaf-trace, and second leaf-trace respectively. 
a is an axillary branch, and r a root-bundle cut obliquely, x 12. 
Figs. 34, 35, and 36. Diagrams of the same node at successively lower levels, 
each, x 12. 
Fig. 37. Enlarged diagram of the stele of the stem shown in Fig. 33. The 
sclerenchyma is shaded, and the protoxylem represented by dots, x 90. 
Fig. 38. Transverse section of the stele of T. scandens. x 140. 
Fig. 39. Transverse section of young petiole of T. scandens , showing three 
protoxylems. x 260. 
Fig. 40. Photograph of transverse section of petiolar bundle of T. apiifolium. 
x about 50. 
Fig. 41. Transverse section of rhizome of T. muscoides. x 480. 
Fig. 42. Bordered pits of tracheide of T. Bancroftii , exceptional in form, 
x 1120. 
Fig. 43. Stoma-like structure in early leaf of T. Bancroftii. x 90. 
Fig. 44. Abortive stoma on filmy leaf of AspleniuTn resectu 77 i ; g ., guard-cells, 
x 255. 
Fig. 45. Abortive stoma on the same leaf; m.c. } mother-cell of stoma, x 255. 
