mer is terns of Ferns as a Phylogenetic Study. 391 
Marattia fraxinea , Figs. 36-41 ( X130). 
Fig. 36. Apex of leaf seen in plan : 0, 0, partial initials. 
Fig. 37. Ditto, from a young leaf with no pinnae. 
Fig. 38. Ditto, from a young leaf. 
Fig. 39. Ditto, but no single initial cell is to be seen : from a leaf on which some 
pinnae were already formed. 
Fig. 40. Apex of a young leaf in median longitudinal section. 0 , a partial 
initial. 
Fig. 41. Ditto, the segmentation of the partial initial (0) has shown some regu- 
larity. x , is the apical cell. 
Angiopteris eveda, Figs. 42-45 (x 130). 
Fig. 42. Apex of leaf seen in plan, p , principal wall. 
Fig. 43. Ditto. 0, partial initials, p, principal wall. 
Fig. 44. Apex of leaf in median longitudinal section, p, principal wall. 
Fig. 45. Ditto. 
WINGS OF THE LEAF. 
Trichomanes radicans , Figs. 46-49 ( X325). 
Fig. 46. Young wing as seen in a transverse section of the phyllopodium. m, the 
marginal cell. 
Fig. 47. Ditto, rather older. 
Fig. 48. Ditto, more advanced. 
Fig. 49. Marginal series of cells ( m , m) seen from without, h , h , hairs. 
Trichomanes reniforme , Figs. 50-51 (X325). 
Fig. 50. Wing as seen in a transverse section near to the base of the leaf : seg- 
mentation of the marginal cell (m) of the polypodiaceous type. 
Fig. 51. Transverse section through the young lamina, showing the large mar- 
ginal cell ( m ) with regular transverse segmentation (compare Figs. 46-48). 
Hymenophyllum dilatatum , Figs. 52-54 (X325). 
Fig. 52. Wing as seen in transverse section of the young petiole: compare 
Fig. 51- 
Figs. 53-54. Irregular segmentations at the close of the functional activity of the 
marginal cells. 
Pteris cretica . 
Fig. 55. Wing as seen in a transverse section of a pinna. ( x 325.) 
Scolopendrium vulgare. 
Fig. 56. Wing as seen in a transverse section of the young leaf near its apex, m, 
marginal cell. ( X 325.) 
Fig. 57. Ditto, more advanced. ( X325.) 
Asplenium resedum. 
Fig. 58. Transverse section through a young pinna, showing, notwithstanding 
the filmy character of the frond, the same marginal segmentation as in Pteris and 
Scolopendrium. ( x 3 2 5 . ) 
