56 M. G. Sykes. 
perhaps one of the first of a chain of genera which were to form 
a long reduction series. 
Conclusion and Comparison with Conifers. If a series of 
relationships such as those sketched above could be proved to have 
existed, I should be inclined to regard the stalk of the “ sporophyll ” 
in Lepidodendron, Spencerites and L. cernuum, etc., as axial in 
nature,—comparable in all species with the similar structure in 
C alamo stachys, Palaeostachya, Psilotacece and Sphenophyllum 1 —and 
representing the axis of a branch, terminated by a single 
sporangium in the one series, by several sporangia in the other 
series, and bearing also a single leaf with which its association is 
probably secondary, not primitive. 1 2 In the simpler Lycopods this 
axis has become reduced and has then finally disappeared ; but 
even here the young sporangium is not developed from the actual 
substance of the leaf rudiment, but from the cone axis, and hence 
arises in the position of an axillary bud. Rudiments, at first 
exactly similar in appearance to the sporangial rudiments, often 
give rise to axillary bulbils. These may be looked upon as due to 
the proliferation of the apex of the reduced axis, which is usually 
terminated by the sporangium. 3 Such proliferation is not necessarily 
a primitive character, but may be traced to purely mechanical 
causes,—for instance, a bud developed from as small a mass of tissue 
as that found in the sporangium stalk of L. cernuum, etc., is 
necessarily itself small, and may well only produce a sporangium, 
but a bud arising from the axis of the cone has more material to 
draw upon, and can thus form stem and leaves. 
It appears that the sum of evidence available is in favour of 
the hypothesis that the simpler Lycopods are reduced, not 
primitive, and that the whole genus Lycopodium contains a series of 
types which are reduced from the larger strobiloid Pteridophytes. 
The foliar position of the sporangium is looked upon as secondary, 
and the Lycopodian sporangium-bearing organ is here supposed to 
have been derived from a branch structure, which had the morpho¬ 
logical value of an axillary bud. 
Whilst our knowledge is still so uncertain, it is impossible to 
attempt any satisfactory comparison between the sporophylls 
of the Lycopodiales and those of Conifers. The female flower of 
Taxus, apparently terminal, but shown by Celakovsky (1879) to be 
1 cf. Sykes, M. G., 1908, pp. 80-83. Text-fig. A. 
2 Ibid, p. 82. 
3 cf. Thomas, 1901, abnormalities in Tmesipteris sporophylls. 
