Lycopodiaceous Cones from the Lower Coal Measures . 393 
i and 4 will show that Lycopodium cermmm far more resembles Mesostrobus 
in the morphology of its sporophyll than it does Spencerites . The resem- 
blance in the mode of attachment of the sporangia is apparently exact, the 
shape of the sporophyll of Lycopodium cernuum after the removal of the 
mucilaginous areas is extremely like that of Mesostrobus , there is in Meso- 
strobus the same ‘ dorsal lobe ’ at the distal end of the sporophyll, and the 
same more or less peltate form. In fact, if Lang’s explanation applies 
to Spencerites it must also apply to Mesostrobus ; that is, the known part of 
the sporophyll of Mesostrobus should have been surrounded on the lower 
side by a mass of tissue which has broken down into mucilage. Now the 
stalk of the sporophyll of Mesostrobus is a neatly finished affair of tri- 
angular section. The actual preservation of the sections is not very good, 
but it appears to be certain that the under surface of the stalk is completely 
covered by an epidermis, in which I have been able to see what I believe are 
stomates. 
If Lang’s explanation applies to Mesostrobus it must also apply to 
Bothrodendron mundum , the sporophyll of which only differs in the short- 
ness of its stalk from Mesostrobus , and to Lepidostrobus , in which this region 
is elongated. It is, I think, unnecessary to point out the improbabilities 
of this position. 
3. There is not the slightest direct evidence that the pedicel of the 
Spencerites sporophyll is not a complete organ. It is apparently surrounded 
by one of the most definite epidermises known in fossil plants, as may 
be seen, for example, in Dr. Scott’s Fig. 11 and Miss Berridge’s Phot. 7. 
4. The sporangia are closely packed in the case of Spencerites , and fill 
up the whole space available with the exception of that occupied by the 
pedicels (cp. Dr. Scott’s Fig. 11, Williamson’s Fig. 55, and Text-fig. 3 of this 
paper). 
It is possible that this might be explained on Dr. Lang’s theory 
by assuming that the mucilaginous portion disappeared before the growth 
of the sporangia ceased. 
5. Dr. Lang’s theory provides not the slightest explanation of the 
origin of the ventral process, and takes no account of the utilitarian purpose 
of the whole arrangement of the peltate ends of the sporophylls. 
This utilitarian purpose is fact, not theory ; see, for example, the lower 
left-hand corner of Dr. Scott’s Fig. 3 and Text-fig. 3 of this paper ; here the 
peltate expansions form a close-fitting mosaic, affording magnificent protec- 
tion to the sporangia. 
6. With regard to the possible coalescence of the distal ends of 
the sporophyll it is impossible to express an opinion without seeing the 
original preparations on which that opinion is based. 
Williamson’s (’ 78 ), Fig. 53, is a particularly unconvincing one, and the 
section appears to be very abnormal : it is according to Lang cut near the 
E e % 
