6o 
Lady Isabel Browne. 
of the roots in the Adder’s Tongues, though not decisive against, 
cannot be held to favour a Lycopodial affinity. 
Endarchy and medullated monostely occur in different members 
of the Lycopod phylum, but the combination of these two 
characters, though conceivable also in the Lycopods, is much more 
filicinean than Lycopodial. The presence of foliar gaps in the 
Ophioglossaceous stele is also a character of some importance 
anatomically, for whether or not foliar gaps are confined to the 
Perns among Pteridophyta, they appear to be absent from the 
Lycopodiales (21). The monarch roots of Ophioglossum seem to 
have been reduced from diarch ones (3); this weakens the force 
of a comparison with those of the Lycopodiales, among whom 
monarchy, if not primitive, is more widely spread than in the other 
phyla. 
Lastly, the argument resting on the intermediate nature of the 
Psilotaceous synangium is much weakened if we recognize, as 
Professor Bower does in his later publications (9), (10), the affinity 
(to be discussed later) of the Psilotaceae to the Spenophyllales ; 
for, if the stalked synangium is the homologue of the sporangiophore 
there is no need to account for the plurality of sporangia by 
septation, since pluri-sporangiate sporangiophores occur in the 
Spenophyllales. Of course the conception of the origin of a group 
of sporangia by septation of a single one might be extended to 
those Spenophyllales in which the sporangiophore bears more than 
one sporangium; but as the sporangia of these fossil forms seem to 
have been normally free from one another, it seems gratuitous to 
regard the cohesion of the sporangia in their recent allies, the 
Psilotaceae, as an intermediate stage between the septation of a 
single sporangium and the development of its loculi as free 
sporangia. 
We must now briefly consider Pi'ofessor Bower’s view of the 
derivation of the Ferns (excluding the Ophioglossaceae) from a 
primitive type not unlike that characteristic of the Lycopods. His 
view hypothecates : (a), the origin of the synangium by septation of 
a single sporangium (5), (6); ( b ), the priority of the Fern synangium 
over the sorus with free sporangia (7) and ( c ), the primitiveness of 
ferns with small and simple leaves (7), (8), (9). The questions of 
the origin of the synangium by septation and its priority over the 
sorus of free sporongia really stand or fall together, for if the latter 
preceded the former the synangium may presumably be regarded as 
formed of coalescent sporangia. As already pointed out in discussing 
