INFLUENCE OF WATER ON LAND-PLANTS 43 
3. The Heath or Ericoid Type (Fig. 12), characteristic 
of many heath-plants—e.g., Hrica, Empetrum, Calluna. 
The leaves are small and their edges are rolled under and 
nearly touch, forming a chamber the entrance to which 
is almost closed by hairs (see Fig. 9). 
4. In the Myrtle-Type the leaves are thick, leathery, 
and evergreen, sometimes large, as in the Rhododendron, 
sometimes small, as in the box. 
Fic. 11.—TRANSVERSE SECTION OF ROLLED Fie. 12. — Hrica 
Lear oF THE MarramM-Grass (Psamma Tetralix, SHOWING 
arenaria). (MAGNIFIED.) HeatH TYPE oF 
‘ Lear. (SLIGHTLY 
a, sclerenchyma ; b, chlorophyll-tissue ; c, vas- REDUCED.) 
cular bundle ; d, epidermis. 
5. The Reed or Juncoid Leaf is long, smooth, and 
circular. The transpiring surface is small, and as the 
leaves are erect, the effect of the sun’s rays upon their 
surface is much reduced. 
§. The reduction of the leaf-surface may be carried 
so far that modifications are rendered necessary in other 
parts of the plant. When the leaf-system is too small 
to accomplish the necessary assimilation, this work has 
to be carried on elsewhere, either by the leaf-stalks, which 
flatten out and become green and leaf-like (the phyllodes 
