195 
Lycopodiales. 
have quite recently been brought to light by Dr. Lang. He has 
shown that the peltate form of the mature sporophyll of L. 
cernuum is due to the disappearance of a mass of mucilage from 
the base of the bulky sporophyll, and suggests that the pseudo- 
peltate form of the sporophyll of Spencerites is also due to the fact 
that a similar mucilaginous mass has escaped fossilization. This 
suggestion is borne out by other points of close similarity between 
the sporophylls of the two genera. In L. cernuum the lower 
surface of the sporophyll bears a small projection ; a similar pro¬ 
jection occurs on the “ dorsal lobe ” of the sporophyll of Spencerites, 
the dorsal lobe on this view representing the base of the sporophyll, 
the more adaxial portion of which has been secondarily hollowed 
out by the disappearance of a mass of mucilage (16). Dr. Lang 
further points out that in the young condition the sporophyll base 
of L. cernuum is coherent laterally with the bases of the sporophylls 
(belonging to the next whorl) on each side of it, and that though 
recent investigators have not referred to any sign of cohesion between 
the sporophylls of Spencerites, indications of such a condition were 
reported by Williamson in his description of the genus (16). The 
similarities pointed out by Miss Sykes and Dr. Lang between 
the cone of Spencerites and that of certain species of Lycopodium 
are interesting, in view of the fact that, so far as we know, 
Spencerites was homosporous, though so few specimens are known 
that the presumption of homospory is but weak. Among the most 
interesting results of Miss Sykes’ researches is the discovery of 
lignified cells in the sporangial pedicel of Phylloglossum and of 
the larger species of Lycopodium ; these, though forcibly recalling 
vascular tissue, and though very close to the sporophyll-trace, are 
never connected with it, though in one case they were in connection 
with the lignified cells surrounding the trace. Miss Sykes, in a 
footnote, asserts the presence of such cells in Miss Berridge’s 
preparation of Spencerites (21); but both the latter and Dr. Scott 
assert the complete absence of vascular tissues in the projection 
of the sporophyll bearing the sporangium of Spencerites (2), (20). 
But though Miss Sykes and Dr. Lang’s suggestion of a possible 
connection between Spencerites and Lycopodium is very valuable, 
it is difficult to agree with the former in her attempt to connect the 
former genus with the typical ligulate Lepidodendraceae. She 
suggests that the small lump of tissue found between the sporangium 
and the distal end of the sporophyll of Spencerites recalls the ligule 
of Lepidodendron (21). But the ligule is situated beyond the insertion 
