LOSS OF WATER 41 
becomes a real source of danger to the plant. Indirectly, 
however, transpiration performs a great service, for it 
aids in, and is probably one of the chief causes of, the 
ascent of liquids taken in from the soil. Were water 
never given off, it would not be possible for tissues, 
FIG. 32. Semperoimim tabulceforme. The arrangement of the leaves 
in a compact rosette, the hairs on their margins, their thick cuticle, and 
other characters, make the plant xerophytic or drought-resistant. 
already turgid, to receive a fresh supply, and, since all 
the elements of plant-food can be carried through the 
plant only in solution, the importance of this point can 
hardly be overestimated. 
The manner in which transpiration may facilitate the 
passage of liquids through the stem may be illustrated 
