126 J. C. Th. Uphof. 
Occurence of Stomata on Leaves of xerophytic Selaginellas. 
Ventral Leaf 
Dorsal Leaf 
Name 
Ligular 
Surface 
Aligular 
Surface 
Margin 
Ligular 
Surface 
Aligular 
Surface 
Margin 
Environment and Locality 
Group I. 
S, rupestris 
none 
pres. 
none 
none 
pres. 
none 
Exposed granite rocks, 
Georgia, U.S A. 
S. rupestris 
” 
” 
” 
9 9 
>» 
Shady moist greenhouse, 
Kew Gardens 
S. rupincola 
99 
” 
9 9 
” 
99 
Exposed rocky place, desert, 
Tucson, Arizona, U.S.A. 
S. avenicola 
99 
99 
9 9 
9 9 
9 9 
9 9 
Dry pine wood, Florida, U.S.A. 
5. densa 
’9 
9 > 
9 9 
” 
” 
Exposed rocky place, 
Montana, U.S.A. 
S, capensis 
’9 
” 
9 9 
99 
9 9 
99 
Exposed place, Orange River 
Colony, S. Afr. 
S. Mildei 
99 
,, 
9 9 
• 9 
9 9 
On rocks, San Luis, Brazil. 
Group II. 
S. borealis 
few 
pres. 
j * 
none 
few 
pres. 
none 
Exposed rocks, Kamschatka. 
S. saccharata 
„ 
,, 
, , 
9 9 
■, 
On bluffs, Guadalajara, Mex. 
S. mongolica 
,, 
,, 
99 
99 
99 
On rocks, Hsai-Watai, China. 
S. sanguinolenta 
” 
9 9 
99 
9 9 
»* 
On rocks, Karrum Valley, 
Afghanistan. 
S. Douglasii 
»» 
9 * 
9 9 
« 9 
9 9 
9 9 
On trees in forest, Oregon, 
U.S.A. 
Group III. 
S. lepidophylla 
few 
pres. 
none 
few 
pres. 
none 
Exposed rocks, Guadalajara, 
Mex. 
S. pilifera 
• 9 
,, 
9 9 
,, 
,, 
Exposed rocks, Sonora, Mex. 
Greenhouse, Kew Gardens. 
S. pilifera 
9 9 . 
9 ' 
,, 
,, 
,, 
S. convoluta 
v 
« 9 
9 9 
9 9 
, 9 
Rocky exposed place, Uraguay. 
S. cuspidata 
,, 
99 
9 9 
,, 
99 
,, 
Lava fields, Tlalpan, Mex. 
S. cuspidata 
,, 
9 9 
9 9 
,, 
99 
9 9 
Greenhouse, Kew Gardens. 
S. imbricqta 
,, 
9 9 
» > 
9 9 
Rocks, Mount Dijot, Arabia. 
S. Pringlei 
9 9 
” 
») 
9 9 
Exposed place, Santa Eulalia 
Mts., Mex. 
S. involvens 
99 
9 9 
” 
none 
” 
Exposed place, Amurland, 
Siberia. 
S. longispicata 
9 9 
9 9 
few 
99 
*’ 
Rocky place, Porfiric Valley, 
Mex. 
cut for microscopic examination. Alcanna readily stains these 
drops red, which is evidence of the presence of oil. This oil is to 
be found in very small drops in the protoplasm when examined 
in water; when the cell loses water or, during plasmolysis, the 
protoplasm shrinks, these drops get larger through union of 
several small ones. In what form oil is present when the cell has 
lost all its available water could not be observed, but the writer 
suggests that a film of oil forms around the entire protoplast or at 
least its vital parts, which is then able to enter the dormant state 
during drought; this condition is very likely the same as that of 
matured seeds, and especially those of Cruciferous plants. Neither 
