INFLUENCE OF WATER ON LAND-PLANTS 45 
thorns; in less xerophytic situations the thorns are 
absent. 
Certain peculiarities in the arrangement and display 
of the leaves are also to be recognized as xerophytic 
Fia. 14.—Cytisus scoparius (ComMMOoN 
Broom). (SLiIcHTLY MAGNIFIED.) 
1. Transverse section of green assimi- 
lating stem. a, sclerenchyma ; 
b, chlorophyll - tissue ; c, cortex ; 
d, phloem ; e, cambium ; /, xylem; 
g, pith; h, epidermis possessing 
stomata at intervals. 
2. Portion of outer tissues, magnified 
more highly to show thick cuticle 
(a), epidermis (6), and chlorophyll- 
tissue (c). 
leaf-mosaic, p. 68). 
adaptations. The hygro- 
phytic type of leaf 
spreads out its surface 
to catch as much light 
as possible, and the 
leaves are so arranged, 
aculeatus 
(ButTcHER’s-BROOM), SHOWING 
CLADODES ARISING IN AXILS 
oF LEAVES AND EacH BEARING 
Fic. 15. — Ruscus 
A Frower. (NatTuraL SIze. 
AFTER KERNER.) 
with respect to each 
other, that every avail- 
able portion of space 
upon which light falls is 
occupied by a leaf (see 
The leaves of xerophytes, on the 
other hand, are not displayed in this way. 
Direct sunlight promotes transpiration, and as this is 
