of the Anatomy of the Genus Selaginella , Spr. 199 
pact cortex, e. g. 5. grandis. In £. viticulosa the endodermal 
cell articulates with two to five or even more long twisted 
cells packed with large chlorophyll-bodies and starch, and 
not infrequently clusters of similar cells arise from the inner 
cortex and partially fill the lacuna, but are quite disconnected 
from the endodermal cells (e. g. 5. sulcata ). In many species 
the endodermal cell articulates with one intermediate distal 
cell or with a single row of such (S. helve tica). In 5. Braunii , 
*S. Poulteri , &c. a reticulum of cells which cannot be distinctly 
recognized as genuine endodermal cells or inner cortical tissue, 
separates the stele from and at the same time connects it with 
the cortex or with another stele. Rows of cells, which are 
identical in character with those of the pericycle, connect the 
steles of such forms as 5. inaequalifolia. Finally, the lacuna 
may be entirely filled with tolerably compact parenchymatous 
tissue through which the endodermal cells run (S. canaliculate!), 
whilst in the creeping axes of several species no distinct 
trabecular tissue is developed at all, the pericycle being in 
such cases continuous with the general cortex. It will be 
seen, therefore, that the well-marked lacuna and specialized 
trabecular tissue of the erect shoots of most species is a quite 
peculiar adaptation easily accounted for and traceable to a much 
more generalized development of intercellular spaces not at 
all uncommon in the Lycopodinae (cf. 27). The pericycle 
invariably consists of one or more (four to five being a maxi- 
mum) layers of long thin-walled cells containing chlorophyll 
(if the axis be above ground), the wall next the lacuna being 
covered with a more or less well-marked cuticle. The peri- 
cycle is always perfectly distinct and easily recognizable. 
The protophloem-elements are delicate, tapering, and semi- 
occluded, occasionally showing a fairly well-marked pitting 
on their walls, and containing, when they exhibit any cavities, 
a small amount of granular proteid substance. The walls are 
very irregular in thickness but always highly retractile. They 
may be best seen, perhaps, in .S. Wallichii , where they are 
very numerous ; in other cases they are few in number, or 
entirely absent. 
