Contributions towards a Knowledge of the 
Anatomy of the Genus Selaginella, Spr. 
BY 
R. J. HARVEY GIBSON, M.A., F.R.S.E., F.L.S., 
Professor of Botany in University College , Liverpool. 
With Plates IX, X, XI, and XII. 
Part I.— The Stem. 
OTWITHSTANDING the exceptionally important 
1 A position which it occupies amongst Pteridophyta, and 
the interest attached to it phylogenetically, the genus Sela- 
ginella can scarcely be said to have received adequate treat- 
ment at the hands of comparative anatomists. The accounts 
of its structure given in the standard botanical text-books 
are based on researches made on a few of the more commonly 
cultivated species, e. g. S'. Martensii , S. caulescens , S. Kraus - 
siana , and S. inaequalifolia ; and although references are not 
entirely wanting to the tissue-systems of other species, it must 
be admitted that a detailed account of the comparative 
anatomy of the genus is still a desideratum. Dangeard, it is 
true, has given us what he terms a { Monographic anatomique 
des Selaginelles ’ (22), where he treats of the structure of twenty- 
eight species, but his account of the anatomy is of the most 
[Annals of Botany, Vol. VIII. No. XXX. June, 1894.] 
