VITTARIA LINEATA 209 
PLATE 27. 
Fic. 75. Basal portion of scale showing the thin-walled cells. X 87. 
Fic. 76. s from the margin half way up th le showing the thin outer wall, 
«t, and the papillae on the thickened inner walls, 6. >< 120. 
Fic. 77. Portion of scale showing the framework of suberized walls, a. 120 
Fic. 78. The characteristic twist of the thin portion of the cross walls at margin. 
YX 210. . 
Fic. 79. View of the back of the scale at base showing bend. > ۰ 
Fic. 80. Base of scale showing twist. X 25. 
Fic. 81, 82. Apex of scales showing the wrinkling of the thin outer wall, a. 
X 875. 
3. Longitudinal section through tip of root : a, root cap; 4, apical portion ; 
"A RE AREN cells ; d, meristem of axial bundle. 45. 
. Tip of root showing how the cap cells often curl before being thrown 
off — a; 4, tienes cap cells still remaining attached to roo 
Fic. 85. Portion of rhizome bundle showing connection of root bundle ; «a, endo- 
‘dermis ; 4, phlo&m ; c, xylem; d, cortex ; c, medullary parenchyma. x 120. 
Fic. 86. Diarch bundle of young root: a, cortex ; 4, endodermis ; ¢, c, phloém ; 
.d, d, two primary xylem groups. X 292. 
Fic. 87. Cross section of young root: a, rhizoids ; رم‎ cells containing crystalline 
‘substances ; c, endodermis ; 4, the two phloém groups ; e, xylem. 8 
Fic. 88. Cross section through root and two of its branches, and a longitudinal 
‘section through a third branch at its point of attachment with the first root: 2 w 
given off first ; then 3; and then 4. Marking as in Fig. 87. X ۰ 
PLATE 28 
Fics. 89, 90. Prothallia and young sporophytes growing on the bark of the pal- 
metto X 4. 
Fic. 91. A wing a, of the prothallium showing young sporophyte ; 4, first leaf ; 
€, root. X ۰ 
Fics. 92, 93. Rudimentary primary leaves showing variation. x 2 
Fic. 94. Variation of secondary leaf. 
95. Mature sterile leaf, the sporophyll shows the same variation with the ex- 
d Es the two primary veins, 4, are apt to run a longer distance before anasto- 
mosing ; 2 is basal portion of 1, they join at æ ; 5 primary veins. ; 
Fic. 96. Apex of first leaf showing epidermis of under side of hyaline border. 
X 87%. 
Fic. 97. Portion of epidermis of same under side: a, gland ; b, stoma. X 210. 
Fic. 98. Portion of epidermis showing prosenchymatic cella. X 210. 
Fic. 99. Scale from upper side of first leaf. X 87. 
Fic. 100. Cross section of petiole showing vascular bundle with two xylem 
groups, b, in primary leaves. 
