90 
THE PRINCIPLES OP BOTANY. 
By Professor Buckman, F.L.S., P.G.S., &c. &c. 
{Continued from vol. 826.) 
We have already described the leaves of plants as being 
a continuation of the bark, which in the case of the leaf is 
spread out into a more or less flattened pagina, or blade, sup¬ 
ported by a more or less branched framework, called by some 
leaf-veins, by others leaf-nerves; but whichever term be 
employed it must not be confounded, either in structure or 
uses, with those parts in animals to which the same names 
have been applied. 
Leaves are sometimes very simple in structure, as in the 
accompanying example, consisting of a central nerve, mid¬ 
rib, and lateral nerves of a like kind. This bears a direct 
resemblance to a parallel veined leaf, but must not be con¬ 
founded with it, inasmuch as in this plant the nerves are 
anastomosed by a most complicated net-work, as may be 
witnessed by an examination of a recent leaf of the common 
Pig. 4.—Leaf of 
plantain. 
Pig. 5. —Leaf of Pig. G. —Violet leaf. 
Porget'iTie-not. 
plantain. In the case before us the leaf may be said to be 
lanceolate —lance-formed—in shape. 
Our next example is that of an ovate leaf, in which the 
margin is still entire, but it is fringed with cilice of fine 
hairs, which, indeed, are seen to cover its surface. This form 
will at once be recognised as ovate, or oval. 
Take another common leaf, that of the sweet violet, and it 
