LEAVES Wy 
The Leaf-Stalk. The leaf-stalk we have seen is that 
part of the leaf by which it is attached to the branch or 
stem. When the leaf is about to fall, a layer of cork forms 
at the junction of the stalk and branch; this layer then 
splits, the leaf falls to the ground, and the wound, instead 
of being raw, is sealed up with a waterproof covering. 
The stalk varies considerably in length—it may be long, 
of medium length, short, or entirely absent. | 
Examples illustrative of the foregoing are readily obtained. 
THE BLADE. 
Shape of Blade. Ifa typical leaf-blade be carefully 
divided down the centre of the mid-rib, it will be found to 
consist of two equal and similar portions. There are 
however a good number of exceptions to this normal 
type, well seen in leaves of Begonia, , 
Blue-gum, Elatostenma Rugosum found 
plentifully in most situations in the 
bush, and in many of the leaves of the 
Poro-poro, Solanum Aviculare.” In shape 
the blade varies considerably : in the 
Pineand Larch 
it is needle- 
shaped ; in the 
Pansy it is egg- 
shaped ; in the 
Convolvulus 
it is arrow- 
shaped ; and 
in the garden 
Nasturtium it 
is circular. 
Examples of 
other shapes 
can easily be Fig. 9—Rhododen- 
Fig. 8.—Quince leaf, showing dron leaf (entire 
whole or entire margin. procured. margin). 
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