856 THE ANATOMY AND AFFINITY OF DEPART A MOORE I. , HOOK. 



EXPLANATION OF FIGURES IN PLATES XCV-XCVH. 



Fig. 1. Transverse section of a pinna just before the lamina is entered. x 24. 



Figs. 2, 3, 4. Transverse sections of transitional region lying between rachis and separation of pinna', 

 and illustrating three steps preparatory to separation of pinnae-traces, x 24. 



Fig. 5. Transverse section of rachis, near its summit. x l'4. 



Figs. 6, 7, 8, 9. Transverse sections of rachis at successively lower levels, and illustrating the varied 

 nature of the leaf-trace. x 24. 



Fig. 10. Transverse section of leaf-base, showing distention of base, sclerotic ground tissue, and five 

 leaf-trace bundles. x 24. 



Fig. 11. Plan of venation and soral position in pinna of Deparia prolifera (Bk.). (Natural size.) 



Fig. 12. Plan of venation and soral position in pinna of Deparia Moorei. (Natural size.) 



Figs. 13, 14. Types of hair on margins of scales (fig. 19). x 24. 



Figs. 15, 16, 17, 18. Types of glandular hairs on lamina. x 24. 



Fig. 19. General form of scale borne on both axis and rachis. x 12. 



Fig. 20. Types of hair found on rachis. x 24. 



Figs. 21, 22, 23. Illustrating the production of the group of marginal cells from the large wedge- 

 shaped marginal initial-cell of the lamina. x 24. 



Fig. 24. Selection of new wedge-shaped marginal cell, and initiation of lower lip of indusium. x 24. 



Fig. 25. Initiation of upper lip of indusium, and the delimitation of the soral-receptacle. x 24. 



Fig. 26. An illustration of the way in which the initiation of the upper lip of the indusium may be 

 delayed. x 24. 



Fig. 27 illustrates the initiation of the upper lip of the indusium upon the upper surface of the 

 lamina and the selection of the first sporangium initial. x 24. 



Fig. 28. A section through a sorus of about the same age as that represented in fig. 27, but cut in 

 plane at right angles to plane of foregoing section. It illustrates the median position of first sporangium 

 initial, and (with fig. 27) the continuity of indusium around the receptacle. x 24. 



Fig. 29. Section of a marginal sorus, with upper lip of indusium well withdrawn from leaf-margin, 

 and a number of sporangial initials of much the same age crowded upon the receptacle. x 24. 



Fig. 30. Section of an older sorus, showing the "mixed " character, and slight basipetal sequence, x 24. 



Fig. 31. Transverse section of the axis showing general disposition and number of meristeles in the 

 greater part of the axis. x 12. 



Figs. 32, 33. Two stages in the development of the superficial sorus. The former shows the partial 

 delimitation of the receptacle, the latter, an advanced stage in the development of the indusium. The 

 middle sporangium is most advanced, and the basipetal succession of sporangia it quite pronounced. x 24. 



Fig. 34. A section of an almost mature marginal sorus, showing the characteristic slight upward tilt, 

 and the "mixed" condition. A slight trace of the basipetal succession remains. x 24. 



Figs. 35, 36, 37, 38. Various views of mature sporangia, to show the vertical position of the annulus 

 and "three-cell" stalk. (Natural size.) 



Fig. 39. Mature spore, with pustulate ridges. x about 40. 



Fig. 40. An accurate reconstruction of half axis of a fairly old plant, and showing part of the lower side 

 of the stele. x 12. This reconstruction was made in the following way. The axis was cut into a large 

 series of sections. These were all kept in their order and proper positions, and camera-lucida drawings 

 made from them. Each drawing was then redrawn as seen "on edge." The drawings thus provided were 

 subsequently " telescoped " so as to give the result of the drawing of a solid body. 



Fig. 41. A view of two mature marginal sori. x about 30. 



