74 THE VEGETABLE WORLD. 
enjoy in the shade and shelter of the forest in’ the burning days 
of summer. 
If the leaves have not the dazzling and variegated colours of 
the flowers of our fields or parterres, their green surface and varie- 
gated shades serve to repose the eye and preserve the sight. The 
movement of the leaves as they gracefully wave to every breath of 
wind, serves also to animate the landscape, and gives it a kind of 
existence. 
But the functions of the leaves are not limited to mere ornament 
and shade. Nature, as we shall see, assigns to them infinitely 
more important offices, both to surrounding nature and to the tree 
of which they form a part. They purify the surrounding atmo- 
sphere, restoring it to its normal condition, rendering it healthy 
and salubrious when vitiated by the breath of animals. The 
Creator has in this, as in all His works, united decorative elegance 
and. beauty of form with direct and immediate utility. : 
Leaves are borne upon the stem and branch, and nothing ise 
more varied than the forms they assume. In Sagittaria, Fig. 87, 3 
they resemble an arrow or spear-head, whence its name. 4n the — 
Juniper bush (Juniperus communis), Fig. 88, its spines are like 80 
many needles. Others have false leaves, as in certain of the 
Gladiolus, which issue from a sheath like the Jris. Leaves m their a 
turn affect the form of a disk, as in the Nasturtium, Fig. 89, or the 
form of a spatula in the Daisy (Scabiosa atropurpurea), Fig. 90. 
Some leaves have forms so strange that botanists have bee? 
puzzled to describe them. For example, in Vepenthes distillatoria, 
Fig. 91, the leaves terminate in a most singular manner; forming 
a sort of urn or vase, surmounted by a cover, which opens and 
shuts as occasion requires. This vessel is suspended at the extremity — 
of a thread-like appendage to a winged petiole, which would seem 
to be altogether unfit to support it. In a recent work we find the 
following facts recorded in reference to the leaves of the Nepenthes — 
distillatoria. Aw officer of marines writes as follows :—“ Three days 
after my arrival at Madagascar, I lost myself during @ short = 
excursion into the interior, and was overtaken with an excessiV@ 
lassitude, accompanied with a devouring thirst. After long 
, walk I was on the point of yielding to despair, when I perceived 4 
close to me, suspended to leaves, some small vases, somewhat 
