of the Anatomy of the Genus Selaginella , Spr. 169 
the Mai'tensii type ; the other, the well-known British species 
S. spinosa , P.B., might be associated with the homophyllous 
forms just described, were it not that the structure of the stele 
in parts of the stem is quite unlike that seen in S. oregana , 
and indeed it is quite unique in some points, so far at least 
as the species which I have examined are concerned. 
35. Selaginella Braunii , Baker. Baker’s Handbook, No. 236. 
In this species there is a well-marked distinction between 
a creeping almost rhizomic axis and erect dorsiventral shoots. 
The chief peculiarity in the anatomy is that whilst the erect 
shoots are monostelic, the creeping axis is bistelic in the fully 
developed condition, and monostelic nearer the spore (PI. IX, 
Figs. 28, 29). The stele of the erect shoot is formed from 
branches from both the steles of the creeping stem where there 
are two steles. The steles in the rhizome lie dorsally and ven- 
trally, and are continued as distinct cords quite up to the meris- 
matic region of the primary creeping shoot. The dorsal stele 
appears first as a dorsal ridge (similar to that seen so markedly 
in the stele of the erect shoot) on the primary stele of the creeping 
axis and after the origin of the first erect branch gradually 
separates away as a distinct dorsal stele. This stele when fully 
developed is broader and flatter than the ventral, and carries two 
marginal protoxylems (at first it has only one like the dorsal 
cord of X. uncinata). The ventral stele is concave dorsally, i. e. 
towards the other stele, and convex ventrally, and bears two 
marginal and generally two ventral protoxylems. The stele 
of the erect shoot is essentially a ribbon with two marginal 
protoxylems ; one protoxylem is contributed by the dorsal, 
the other by the ventral rhizomic stele. These two portions 
run distinct for a short distance, and then fuse into the single 
ribbon-like stele of the erect shoot. The vascular cylinder of 
the root is formed in a similar manner. The stele is elliptical 
in section and in the youngest branches consists of two 
marginal protoxylems united by procambial tissue and sur- 
rounded by phloem and pericycle. Beneath the first branch 
a third dorsal protoxylem appears, beneath the next a fourth. 
The procambium now becomes gradually transformed into 
