396 
DR JOHN M‘LEAN THOMPSON ON THE 
Fig. 7. Transverse section of leaf-trace in a small leaf inserted towards the under surface of the axis. 
( x 45.) 
Fig. 8. Transverse section of a root. ( x 30.) 
Plate II. 
Jamesonia scalaris, Kze. 
Fig. 9. Transverse section of a normal leaf-trace as seen in the leaf-base. ( x 45.) 
Fig. 10. Transverse section of a normal leaf-trace from which the pinna-trace supply is marginal. ( x 45.) 
Figs. 11-14. Various sporangia; 11, 12, lateral views; 13, a front view; 14, an apical view. (All 
x 40.) These serve to show that the annulus is vertical, and interrupted hy the stalk; the construction 
of the stomium is variable, and irregularities exist in the indurated ring. 
Figs. 15, 16. Top and bottom views of the tetrahedral spore. ( x 40.) 
Fig. 17. A sporangium opened. It shows a regular annulus. ( x 40.) 
Figs. 18-20. Opened sporangia, in each of which the annulus is irregular. Irregularities occur in various 
positions. ( x 40.) 
Figs. 21-23. A series of sections of fertile pinnae, showing a progression from a simple to a “mixed” 
copdition during sporangial development. (All x 45.) 
Plate III. 
Jamesonia scalaris , Kze. (figs. 24, 25), and Llavea cordifolia, Lagasca (figs. 26-31). 
Figs. 24, 25. Sections of fertile pinnae of Jamesonia scalaris, Kze., showing later stages of the “mixed” sorus. 
Fig. 26. Transverse section of the abaxial portion of the leaf- trace on its passage from the leaf-base to 
the stele. ( x 45.) 
Fig. 27. Section of a portion of a fertile pinnule showing the mixed condition of the sporangia. ( x 45.) 
Fig. 28. Scale from the stem. ( x 18.) 
Fig. 29. Hair from the stem. ( x 40.) 
Fig. 30. Front view of a sporangium with an irregular annulus. ( x 40.) 
Fig. 31. Reconstruction of a portion of the vascular cylinder of the axis. ( x 5.) 
Plate IV. 
Llavea cordifolia, Lagasca (figs. 32-39), and Gymnogramme ( Trismeria ) trifoliata (L.), Fee (figs. 40, 41). 
Fig. 32. Various views of the tetrahedral spores. ( x 60.) 
Fig. 33. Side view of a sporangium with a regular annulus. ( x 40.) 
Fig. 34. An irregular annulus showing a double series of indurated cells. ( x 40.) 
Fig. 35. A regular annulus. ( x 40.) 
Fig. 36. An irregular annulus showing imperfect lignification of certain cells. ( x 40.) 
Fig. 37. Back view of a sporangium with a broken annulus. ( x 40.) 
Fig. 38. Top view of a sporangium with irregular and imperfectly lignified annulus. ( x 40.) 
Fig. 39. Top view of a sporangium which has no stomium, but in which the indurated cells form an 
apical crescent. ( x 40.) 
Fig. 40. Scale from the stem. ( x 24.) 
Fig. 41. Section of a portion of a fertile pinna. ( x 45.) 
Plate V. 
Gymnogramme ( Trismeria ) trifoliata (L.), Fee (figs. 42-47), Cryptogramme crispa (L.), R. Br., and 
Gymnogramme japonica (Thnby.), Desv. (figs. 48-54). 
Fig. 42. Section of a portion of a sterile pinna. Bods and granules of wax are on the outer wall-surfaces 
of the lower epidermis. ( x 60.) 
Fig. 43. Top view of a sporangium with an irregular annulus. ( x 40.) 
Fig. 44. Side view of a sporangium with a regular annulus. ( x 40.) 
