Index . 
ix 
Figures. 
8. Longitudinal section of a young pinna of Schizaea rupestris, showing 
the slightly acropetal sequence of sporangia (Bower) . 
9. Transverse section through a number of pinnae, showing their relation 
to one another (Bower). 
10. Transverse section of a pinna of Schizaea digitata, showing the 
indusial flaps much larger in proportion (Bower) .... 
11. a, b. Longitudinal sections following the marginal series of cells of 
the pinna of Schizaea digitata, and the sporangia which arise there 
(Bower). 
12. Longitudinal section through the apex of a pinna of Mohria caffrorum, 
showing the apparently superficial position of the sporangium, 
which is actually marginal in origin (Bower) .... 
13. i-iii. Vertical sections through the young sorus of Lindsaya linearis, 
in successive stages of development (Bower) .... 
14. i-iv. Sporangia of Lindsaya linearis from various points of view 
(Bower). 
15. Transverse section of a sporophyll of Dictyoxiphium panamense 
(Bower). 
16. Transverse section near to the base of the petiole’of Saccoloma elegans 
(Bower). 
17. a-l. Series of transverse sections of the stem of Saccoloma elegans, in 
succession from below upwards (Bower). 
18. a-e. Sections through the pinnule margin of Pteridium aquilinum, 
showing how the receptacle originates directly from the marginal 
segmentation, while the indusial flaps are superficial in origin 
(Bower). 
19. a. A more mature sorus showing strong basipetal sequence of sporangia 
in Pteridium aquilinum, var. caudatum. b. A similar section from 
Scotch Bracken, showing a mixed sorus (Bower) .... 
20. Vertical section of the fusion-sorus of Pteridium aquilinum, following 
the line of the commissure (Bower). 
21. i, ii. Vertical sections of pinnule of Pteridium aquilinum, where the 
sorus is merging into the sterile margin (Bower) .... 
22. A-c. Vertical sections of the sorus of Paesia viscosa (Bower) . 
22 bis. A-C. Vertical sections through the sorus of Paesia scaberula (Bower) 
23. i-iii. Stele and origin of leaf-traces in Pteris (Histiopteris) incisa 
(Bower). 
24. A-H. Section vertically through the margins of pinnules of Histiopteris 
incisa, showing the relation of soral origin to the marginal segmenta¬ 
tion (Bower). 
25. i, ii. Vertical sections through more mature sori of Histiopteris incisa 
(Bower). 
26. «, b. Transverse sections of the petiole of Pteris (Litobrochia) podo- 
phylla; c-f show the steps of change to form the two first pinnae; 
g-i show the stalks of those pinnae, and of the rachis (Bower) 
27. i-iv. Vascular system of the young plant of Pteris podophylla, as seen 
in successive transverse sections at its base (Bower) 
27 bis. v-viii. Similar sections of Pteris podophylla, showing a more 
advanced state (Bower). 
28. a-d. Vascular system of an old plant of Pteris podophylla seen in 
transverse sections successively from below upwards (Bower) 
29. a-c. Vertical sections of the young sorus of Pteris longifolia 
(Bower).- 
30. a-c. Sections through the young sorus of AnOpteris hexagona (L.), 
C. Chr. ( = Pteris heterophylla, L.),.showing the origin of the soral 
hairs (Bower). 
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