THE ANATOMY AND AFFINITY OF STROM ATOPTERIS MONILIFORMIS, METT. 151 
were counted and were found to number about 480, all of which appeared to 
be fully developed. In itself the sporangial form bore strong evidence of the 
Gleicheniaceous affinity of Stromatopteris, and the spore-count greatly strengthens 
this relationship. But while the bond of kinship of these plants is thus further 
tightened and strengthened by the evidence of the spore-output in Stromatopteris , 
the gulf between Platyzoma and both Stromatopteris and Gleichenia remains wide. 
Both Platyzoma and Stromatopteris are clearly seen to be xerophytically reduced and 
specialised types, but the latter has been conservative of the stock character of spore- 
output, whereas the former has drifted further in- this respect than in any other 
from the Gleicheniaceous type, lor the highest spore-count which has been made in 
Platyzoma is 32. 
Two sporangia of a more aberrant type remain to be mentioned. The first is 
represented in figs. 71 and 74. On its upper slanting surface is a rosette of eight 
indurated cells, displayed around a single central cell. There is no defined zone of 
dehiscence, but dehiscence is probably accomplished vertically on the convex un- 
indurated side. This sporangium was unopened, and accordingly supplied a second 
spore-count. It contained at least 416 mature spores. The second anomalous 
sporangium is represented in figs. 72 and 73 as seen from above and below'. It has 
an apical cap of four unthickened cells, bordered by a perfectly transverse uniseriate 
annulus. There are thirteen indurated cells, a clearly defined zone of dehiscence, 
and vertical dehiscence. Its stalk is short and massive. This sporangium was 
empty. The form of the first of these anomalous sporangia is suggestive of that 
of certain of the Scliizxas, but the consensus of the other features, and in particular 
the characters of the majority of the sporangia and the spore-output of Stroma- 
topteris, are distinctly against a Schizxa affinity. The spore-output is much higher 
than that of any known member of the Schizseacese, and harmonises well with the 
Gleicheniaceous types. The form of these two sporangia is considered an anomaly 
of which other examples probably occur, but it is not considered hostile to a 
Gleicheniaceous affinity for Stromatopteris. It rather serves as a proof of a certain 
aloofness on the part of Stromatopteris, than as a suggestion of a possible link 
with Schizxa. 
The spores are all of one type (figs. 69 and 70). They are remarkably thin-walled 
and smooth, and suggest structures designed for quick germination. 
General Conclusions. 
When the details given above are surveyed, it is found that structurally Stroma- 
topteris comes well in line with most Gleichenias, but is possessed of an individuality 
of form which is not matched by any known Gleichenia. It may be held that many 
of its peculiarities are consequent on the assumption of an erect position by the 
branched portions of the axis, and are accentuated by the poverty in roots, or the 
