The Cones of the Genus Selaginella. 
BY 
M. G. SYKES, 
Girt on College , Fellow of Newnham College , Cambridge. 
AND 
W. STILES, B.A., 
Assistant-Lecturer in Botany in the University of Leeds. 
With Plate XLI. 
I N this paper we do not propose to give an exhaustive account of the 
cones throughout the genus Selaginella , but merely, by describing a few 
of the more typical species, to draw attention to the great divergence in the 
form of the sporophylls found in this genus, and in each case to point 
out the special adaptations for the secure protection of the sporangia. Some 
of the more complex forms of cone are found to prevail in species which from 
their radially distributed leaves have been regarded as more primitive in 
the genus than are the dorsiventral species ; this fact is of some interest 
when considered in relation to various difficult questions concerning the 
development of the sporangium-bearing organs among the Pteridophyta. 
The material of S', pumila was obtained by Professor Pearson at 
Stellenbosch, Cape Colony, and was handed over to us by Professor 
Seward ; S', spinosa and S. helvetica were collected by one of us in 
Switzerland ; we also examined S. Vogelii , S. Jlabellata , and S. apus 3 var. 
elegans , grown in the Cambridge University Botanic Garden, and S. cati- 
lescens , of which we used laboratory material. Our thanks are due to 
Mr. Lynch for kindly sending S. apus , var. elegans 3 to Kew for identification. 
Descriptive. 
General. No attempt has hitherto been made to distinguish between 
the forms of sporophyll characteristic of the various species of Selaginella . 
Besides the simple sporophylls commonly attributed to the genus, closer 
examination has now revealed several more complex types. Before de¬ 
scribing these it may be well to refer to some characters which are common 
to all or several of the species. 
The cones are usually square, with four rows of sporophylls. The 
sporangium is generally borne in the axil of the sporophyll. As has been 
[Annals of Botany, Vol. XXIV. No. XCV. July, 1910.] 
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