92 



of the arcliegoiiiiim. The second or quiidrant wall is as usual 

 at right augles to the basal wall. If the archegonium is on one 

 side of the uiidiib and thus lies horizontally, the quadrant wall 

 like the Ijasal wall also lies in the plane of its axis, as in 

 Osmunda. If it is one of tlie younger archegonia lying directly 

 back of the growing point the arrangement of the quadrants 

 with reference to the archegonium is exactly like tliat of the 

 Polypodiaceae. As in the other leptosporangiate ferns that 

 have been studied, the epibasal or anterior quadrant gives rise 

 to stem and leaf, the posterior quadrant, to root and foot. 

 Fig. Ill (PI. XIII) shows a nearly median horizontal section of a 

 youug embryo of G. pectinaia. The archegonium in this case was 

 lateral in position and hence it is sectioned nearly longitudinall}^ 

 Fig. 112 (PL XIII) shows three sections of the same embryo. The 

 large cell, r (in h), is probably the apical cell of the primary root. 

 Rauwenhoff found in G. dlcarpa that the apex developed very 

 early. Fig. 112 c shows i\\Q epibasal quadrants forming respectively 

 stem and leaf. The large triangular cell in each quadrant is 

 presumably the initial for the stem and leaf respectively. Figs. 

 116—118 (PI. XIII) show three sections of a much older embryo 

 of G. dlckotoina. The embi'yo is much elongated and the foot is 

 relatively large, occupying nearly the entire bulk of the embryo. 

 The stem-apex {st) is not cut quite straight, but nevertheless 

 shows the apical cell. The apex of the leaf was injured Init to 

 judge from a study of older stages there is little question that 

 the leaf also grows from a single initial cell having two series 

 of segments as in the typical ferns. The apical cell of the root 

 is very conspicuous and shows the characteristic tetrahedral 

 form. In the axis of the embryo the first trace of the vascular 

 bundle can be] seen, — a strand of narrow procambiumcells. 

 The root usually emerges first, and in most of the sections was 

 broken oil or injured, so that no satisfactory studies of the apex 

 in the later stages were obtained. However, to judge from the 

 earlier stages, it does not differ from the roots that are formed 

 later (PI. XIV, Figs. 120, l:]0). 



The cotyledon grows rapidly and soon breaks through the 



