363 
Cortex of Selaginella, Spr. 
S. inaequalifolia, Spr. 
In young stems the deposit is small in amount and can 
scarcely be said to do more than form a thin lining to 
the cortical wall of the lacuna, though here and there it 
penetrates between the cells of the innermost layer of the 
cortex. In old stems, however, the appearance presented by 
the deposit is very similar to that seen in 5. grandis. As 
this species is very commonly used for laboratory study, 
perhaps I may add that the deposit is very clearly seen 
in sections mounted in balsam. The figure from Sachs’ 
Text-book, quoted in De Bary’s Comparative Anatomy of 
Phanerogams and Ferns, and indeed in most other text-books 
treating of the genus, represents no such deposit. As a matter 
of fact the figure is more fatally erroneous in other respects — 
for instance, three steles are represented, each with two 
protoxylem-masses, one at either margin ; whilst in reality 
there are twelve to fifteen protoxylems (in a full-grown stem), 
each stele having at least four. The two lateral steles are 
also occasionally double, two within one lacuna. I need not, 
however, discuss the anatomy further in the present paper. 
S. Lobbii, Moore. 
In the large suberect stems of this species a small amount 
of Si 0 2 may be distinguished lying on and round the 
innermost cortical cells. The quantity is very small com- 
pared to that in some of the other species described. There 
are no special features of the deposit in this form that require 
description. 
S. haematodes, Spr. 
The thick-walled sclerotic cells lining the cortical wall 
of the lacuna have a small incrustation of Si 0 2 , which 
penetrates between the cells, but is not traceable beyond 
the third layer. There is no deposit on the swollen 
parenchyma, which partially fills the lacuna. 
S. suberosa, Spr. 
The deposit in this species is also small in amount and 
