6 4 
Lady Isabel Browne. 
of the sterile lobe (28). In the absence of vegetative organs he 
hesitates to draw any conclusions as to the morphology of the cone 
of Cheirostrobus, but he suggests tentatively that its more bulky 
sporangiophores may be formed by the coalescence of two lateral 
lobes comparable to the sporangiferous peduncle of Sphenophyllum 
Dawsoni. These theories of Professor Lignier are ingenious and 
suggestive, but though the conception of a few highly compound 
frond-like leaves as the primitive type of sporophyll in the Spheno- 
phyllales seems helpful, there is little in support of the view that 
the adaxial position of the sporangiophores is due to shifting. A 
dorsiventral division of the sporophyll is a marked character in such 
different types as Palceostachya, Calamostachys, Cingularia, Cheiro¬ 
strobus, Sphenophyllum Dawsoni, S. fertile and Bowmanites Roemeri, 
and it is thus not unlikely that it is a primitive character. But even 
if we hold to a filicinean affinity for the Sphenophyllales, it is not 
necessary to regard the adaxial position of the sporangiophores as 
due to displacement, for in many Botryopterideae the fronds branched 
in more than one plane, and it has been suggested that this was a 
primitive character. But whatever view we take on such points 
points of detail there remains a wide gulf between a fertile fern- 
frond and a sporophyll of any known Sphenophyll. 
In the same way Professor Lignier seeks to bring the fructifi¬ 
cations of the Equisetales into relation with those of the Ferns. 
The more massive sporangiophores of such a type as Calamostachys 
are regarded as bisporangiate pinnules displaced to an adaxial 
position and coherent in pairs to form a quadri-sporangiate peltate 
sporangiophore. These sporangiophores are frequently inserted 
half-way between two sterile whorls, and such a position is regarded 
as due to concrescence of the lower part of the sporangiophore 
with the axis of the spike. Whether or no the adaxial position of 
the sporangiophores is due, as Professor Lignier claims, to shifting 
there is some probability, from an analogy with Cheirostrobus and 
Sphenophyllum fertile, that the sporangiophores are lobes of the 
sporophylls, and that their position on the axis is secondary. Mr. 
Hickling’s researches show, however, that Palceostachya can no 
longer be regarded as an intermediate form (18). The view that 
the peltate sporangiophores of Calamostachys or Calamodendrostachys 
represent two coalescent sporangiferous pedicels of Sphenophyllum 
Dawsoni- type is open to grave objections. Not only does the course 
of the vascular strand of the sporangiophores afford no indication 
of a double origin, but they are most naturally compared to those of 
