Contributions towards a Knowledge of the 
Anatomy of the Genus Selaginella, Spr. 
BY 
R. J. HARVEY GIBSON, M.A., F.L.S., 
Professor of Botany in University College , Liverpool. 
With Plate IX. 
PART III. THE LEAF. 
MONGST the older monographs, the first important 
-L\- contribution to our knowledge of the anatomy of the 
leaf of Selaginella occurs in Hofmeister’s treatise on the 
Structure and Development of the Higher Cryptogams h 
Dealing more especially with the species S’, denticulata , 
S'. Galeottei , and S. Martensii , he first of all gives an account 
of the mode of development of the leaf, describing it as 
arising as a horizontal ridge of cells, embracing about one 
quarter of the circumference of the stem, and first appearing 
about eight or ten cells behind the apical cell. The cells 
forming the ridge undergo division in such a manner as to 
give origin to a plate two cell-layers in thickness, the central 
cells of the ridge dividing more actively than those nearer the 
edge. On either side of the middle line the cells undergo 
1 Vergleichende Untersuchungen der hoheren Kryptogamen. Leipzig, 1851. 
[Annals of Botany, Vol. XI. No. XLI. March, 1897.] 
