402 Farmer and Hill. — Angiopteris evecta . 
EXPLANATION OF FIGURES IN PLATES 
XVI, XVII, XVIII. 
Illustrating Professor Farmer and Mr. Hill’s paper on the arrangement and 
structure of the vascular strands in Angiopteris evecta , &c> 
Abbreviations. 
a. apical cell; cb. cambium; com. commissure ; c.t. (Fig. 22) crushed tissue; 
end. endodermis ; f,g. foliar gap ; l.t. leaf-trace ; £. parenchyma ; ph. phloem ; p.r . 
primary root ; p.x. protoxylem ; rt. root ; r.a, apical cells of root ; st. stele ; s.t. sieve- 
tube ; t.2. secondary tracheids; t.$. tannin sac; x. xylem; x.p. xylem parenchyma. 
Fig. 1. Young stele of Angiopteris evecta , side view ( x about 50). 
Fig. 2. Older stele, two foliar gaps are seen near the apex. 
Fig. 3. Portion of stele of older plant showing the foliar gaps. 
Figs. 4, 5. Two different views of the stele of a still older plant showing the 
transition from the preceding simple, to a more complicated, structure. (The 
numbers of the roots and leaf-traces refer to the same individual members in the 
two figures.) 
Fig. 6. Stelar system from a much older plant. (The natural proportion 
between the length and breadth is here somewhat exaggerated, in order to render 
the parts more distinct.) 
Fig. 7. Upper portion of a siphon ostele of Marattia fraxinea viewed obliquely 
from above ; x 12 (cf. Figs. 20 and 21). 
Fig. 8. Transverse section of the primary diarch root of Angiopteris. 
Fig. 9. Section from the same root in the transitional region between root and stem. 
Fig. 10. Section from the’saipe still higher up showing formation of intraxylar 
parenchyma. 
Figs. 11-13. Angiopteris. Transitional region from another series showing 
formation of a pith ( x 170). 
Fig. 14. Longitudinal section or apex qf stem of Angiopteris showing apical cell. 
Fig. 15. Transverse section of apex of stem of Angippteris. 
Fig. 16. Kaulfussia aesculifolia. Transverse section of stele showing endodermis. 
Fig. 17. Angiopteris. Transverse section of stem showing the exit of a leaf-trace, 
It., and the fusion of a root stele, rt. , with the central strand. 
Fig. 18. Angiopteris. The origin of a root in the apical region of the stem. 
x.a. Root apex. 
Fig. 19. Angiopteris. Central strand, root, and leaf-trace, with sieve- tubes 
within the stele. 
Fig. 20 (cf. Fig. 7). Marattia. Stqlar system as seen obliquely from above. 
Fig. 21. The same viewed from the side. 
Fig. 22. Marattia. Transverse section of stele in the stem, showing merismatic 
tissue. Endodermis well marked. 
Fig. 23. Angiopteris. Transverse section of the stem with secondary tracheids 
and an internal phloem. 
Fig. 24. Angiopteris. Leaf-trace. 
Fig. 25. Same with increased development of xylem (x 290). 
Figs. 26, 28. Angiopteris. Transverse section of stem, showing secondary 
formation of tissues. 
Fig. 27. Angiopteris. Division in extra-stelar tissue. Longitudinal section of 
the stem. 
