Sporangium-bearing Organs of the Lycopodiaceae. 45 
much longer stalk, and, consequently, although the incurved edges 
of each sporophyll fold round its sporangium, so that the latter 
receives a certain amount of protection, it is still distinctly visibly 
between the sporophylls ; (PI. II., Figs. 4a, b, and Text-fig. 4, VI.) 
Dehiscence of the sporangium takes place along an apical slit. 
A mucilage cavity is present in the base of the sporophyll of 
L. squarrosum. No cells with lignified walls are found in the 
pedicels of the sporangia of either of these species. 
(ii.) Phlegmaria. In this group the sporophylls are aggregated 
to form distinct terminal spikes or cones, and are more or less 
modified in shape. L. nununularifolium and L. phlegmaria were 
examined. The sporophylls of these species (PI. II., Fig. 6), resemble 
those of L. dalhousianum, but their edges are more closely incurved 
round the sporangia. Cells with slightly lignified walls are found 
in the sporangium pedicels (cf. PI. III., Fig. 2); no mucilage cavities 
are present in the sporophylls. The sporangium of L. phlegmaria 
has an exceptionally long stalk, and dehisces by means of an 
apical slit. 
B. Rhopalostachya. 
(iii.) Inundation. In the species L. inundation, which by 
Baker is placed with L. phlegmaria, we find for the first time 
considerable modifications in the structure of the sporophyll, though 
the external difference between the sporophyll and the vegetative 
leaf is small. 
Each sporophyll is of considerable thickness and has a 
prominent dorsal ridge (PI. II., Figs. 5a, b). This ridge projects from 
the back of the sporophyll and overlaps the sporangium belonging 
to the sporophyll immediately below. The sporangium is thus far 
less exposed than it is in the Urostachya, but it is still visible 
on the exterior of the cone. A mucilage cavity is found in the ridge 
(Text-fig. 5, VII.) The sporangium is large and is borne on a 
very short, wide stalk, in the axil of the sporophyll ; numerous 
elongated cells with strongly-lignified, pitted walls (PI. III., Figs. 4,5), 
are found in this stalk, but there is no connection between these 
and the vascular elements of the sporophyll trace. In the tracheides 
of the trace many interesting examples of a transition from 
scalariform to reticulate pitting were noticed 1 (PI. III., Fig. 6). 
Pritzel places L. caroliniamon with L. inundation, and a study 
of the sporophylls certainly confirms this arrangement 2 . The 
1 cf. H. Gibson, 1894, Fig. 101, PI. XII. 
1 See also Bower, 1908, p. 313. 
