VITTARIA LINEATA 211 
IG. . A, represents width of groove from edge to the sporangial layer; Û, 
stoma ; c, initial cell; g, original epidermal cell 
Fic. 123. Cross section of groove: a, stoma; 4, epidermal cell; v, air space; d, 
thick- ated cells around bundle; e, thin-walled epidermal layer giving rise to the 
sporangia, /, and paraphyses, g. 20 
Fics. 124-126. Showing origin of the stoma: a, original epidermal cell; 5, in- 
itial cell of the stoma; c, the mother cell of the stoma; 4, longitudinal wall Ars 
mother cell, in Fig. 126, dividing it into the two guard cells, e, e; f, nucleus; g, 
chlorophyl. X 294. 
FIG. 127. Mature stoma. Dotted line, 4, represents wall of mother cell, the two 
guard cells being raised somewhat above the epidermis as in the cross section (Fig. 
123). Marking as in Figs. 124-126. X 310 
Fic. 128. Gland. X 294. 
PLATE 31 
Fic. 129. A diagram of the longitudinal section of the leaf passing through center 
of groove : a, upper epidermis and band of thick- و‎ cells ; 4, mesophyll ; c, c, band 
of thick-walled cells surrounding bundle; 4, lateral bundle; e, thin-walled layer of 
epidermis giving rise to the sporangia ; /, sporangia here shown in all stages of devel- 
«ad, g, the paraphyses. X 25. 
130. ent sections showing the development of the sporangium : a, or iginal 
cell x pd sporangium; 4, first oblique wall; c, second wall; 4, first tetrahedral cell ; e, 
CE cell dividing to form the sporangial wall. No. 9 shows the divisions of T 
trahedral cell, which form the mother cells of the spores and the tapetal cells, £, 
pelis No. 5, surface view of very young sporangium. X 120. 
FIG. 13 urface views of older sporangia: «a, annulus; 4, lip 
cells just forming ; c, cells of pedicel at base of sporangium. X 120. 
FIG. 132. Mother cells from a yourlg sporangium before dividing to form the spores. 
10, 
133. Young و‎ all the cells containing chlorophyl, except the lip 
ce ۱ a, دس‎ us; 4, 4, four connective cells; <, the four lip cells; 4, thin-walled 
cells of ag at wall; e, prin x 120 
G. 134. Ripe en showing the way in which it opens : f, spores. 
ws as in Fig. 133. X 1 
135. Different ways in which cells of divide ; part of the basal por- 
tion xs is sporangium is shown at a in No. 1. 1, X 87. No. 2, X 120. 
Fic. 136. Four cells SF epidermal layer, a, one of which has given rise to a 
T 1 û c, first tetrahedral cell in process of dividing (this stage is be- 
tween Nos. 8 and 9 of Fig. 3 IE ^ To wall; e, pedicel ; /, young paraphy- 
sis from adjoining cell containing a nucleus and some chlorophyl. X 120 
Fics. 137, 138. Young 9۵ ru 120. 
Fic. hi Seven diagrams showing the branching of the paraphyses. 
Fic. 1 . Young sporophyte, 4, growing from mutilated end of rhizome, the 
growing ae id rhizome having been removed ; a, base of two old sporophytes. 
Mark- 
