366 Proceedings of the Royal Society of Edinburgh. [Sess. 
connections as belonging to the sporophyll-bases of the alternating whorl 
above. On the right-hand side the plane of section appears to have passed 
through the sporangial attachments, and the connections between the 
sporophylls are best seen a short distance round from this on the lower side 
(at c" and further round). The section is comparable with one of the 
three sections which have been seen above to afford evidence of the 
cohesion of sporophyll-bases in the mature cone of L. cernuum. I have 
obtained corroborative evidence of the connection of the distal parts of the 
sporophyll-bases, in a section from Dr Kidston’s collection, passing in a 
corresponding plane through the lower region of a cone of Spencerites ; in it 
the pedicels are horizontal and the sporangia normal. If continuity of the 
distal portions of the sporophyll-bases in Spencerites , corresponding to what 
is found in L. cernuum , can be established, as seems probable, we are forced 
to assume a similar disappearance of the connection of the proximal 
portions in the two cases. The evidence derived from these transverse 
sections thus supports the interpretation suggested by the corresponding 
shape of the sporophylls in the two cones as seen in radial section. There 
is reason to think that at c'" in Williamson’s fig. 53, the connection between 
the proximal portions of the sporophylls is persistent and preserved. 
I have confined myself in this preliminary statement to giving an account 
of the general morphology of the cone of Lycopodium cernuum and of 
showing that a number of features in the cone of Spencerites can be inter- 
preted in the light of what is known of the living plant. The discussion 
of the difficulties in the way of the homologies suggested above, and of the 
general questions which they raise, must be deferred until a full description 
can be published. One difficulty which I have felt strongly is the apparently 
definite limitation of the surface of those regions of the pedicel and axis in 
Spencerites that are assumed to have abutted on a mucilage cavity and not 
to have formed part of the original, free, outer surface of the plant. It can 
only be said here that little or no distinction can be made in L. cernuum 
between the tissues in the same relative positions. 
The facts adduced, though not amounting to a demonstration, appear to 
afford a prima facie case for regarding the cone of Spencerites as having 
been constructed on essentially the same plan as that of L. cernuum. This 
involves the view that in the mature cones of Spencerites , which are alone 
known, the inner and lower portions of the dependent sporophyll-bases had 
been removed or destroyed before petrifaction. The pedicels would thus be 
the equivalent of the persistent upper portion of the sporophyll-base in 
L. cernuum , and the dependent “ dorsal lobe ” of the outer (abaxial) portion 
of the sporophyll-base. The disappearance of the presumably mucilaginous 
