216 Pteridophyten. 



and a considerable amount in the sporophylls and vegetative leaves 

 of all those examined bj^ him. The main vascular Strand of the spo- 

 rophyll is concentric; so are its branches. It is held that these facts 

 tend to bring Equisetum nearer to the Calamitae, especially to 

 Calamites pettycurensis. Finally the author upholds Jeffrey's view 

 that there are no foliar gaps in Equisetum. Isabel Browne. 



Sykes, M. G. and W. Stiles. The cones of the genus Selagi- 

 nella. (Ann. of Bot. XXIV. p. 523—526. 1910.) 



The authors describe five types of sporophyll found in the genus 

 Selaginella: the first type occurring in 5. puniila and 5. rupestris 

 has a well developed dorsal Aap extending freely downwards and 

 protecting the sporangia of the whorl below. The second type of 

 sporophyll, recorded only from Sh. spinosa, is flat except for a 

 very slight dorsal projection and the sporangia are much exposed. 

 The third type of sporophyll has a decurrent dorsal projection, 

 which, even in the young cone, affords very little protection to the 

 sporangia of the whorl below. The fourth type of sporophyll is 

 found in 5. caulescens and 5. flabellata; here the sporophyll is 

 more closely folded round the sporangium then in the species as yet 

 mentioned; a dorsal ridge projects downwards and turns up again a 

 little at the base. In the fifth type, termed by the authors type 4b, 

 the sporophyll is so folded round the sporangium as to appear V- 

 shaped and there is no dorsal Aap or ridge. The authors hold that 

 the first and most complex type of sporophyll is the more primitive; 

 this is supported by the fact that the two species from which this 

 first type of sporophyll has been recorded are not dorsiventral; it is 

 also suggested that the remarkable resemblance of this complex type 

 of sporophyll to that of Lycopodium alpinum, L. cernimm and Spen- 

 cerites is significant. The large simple sporophylls of the equally radial 

 5. spinosa are regarded as reduced from the first type of sporophyll. 

 The third type of sporophyll, that with a decurrent dorsal projection, 

 is also regarded as derived from the first type which has, as already 

 mentioned, free dorsal projection; the fourth type of sporophyll is 

 also held to be derived, independently of the other types just enu- 

 merated from the first complex type of sporophyll; finally it is held 

 that the species included in the fifth type represent a further stage 

 and that they have probably passed through a phase of sporophyll 

 reduction to-day represented by forms with sporophylls belonging 

 to the fourth type. The sporophylls of this fifth type have lost all 

 trace of the dorsal projection. 



Lignified cells occur in the sporangial stalk of several species 

 of Selaginella, but are hardly comparable to those occurring in the 

 sporangial stalk of Lycopodium for unlike the latter they seem to 

 be unpitted. In 5. Vögelii it was found that the megasporangia were 

 constantly in excess of the microsporangia and one plant at least 

 produced only megasporangia. Isabel Browne. 



Worsdell, W. C, The rhizophore of Selaginella. (New Phyto- 

 logist. IX. p. 242. 1910.) 



The author thinks it improbable that we should possess, at so 

 late a period of evolution, organs too undifferentiated to be classed 

 as roots stems or leaves. The arguments in favour of the cauline 



