"If you would make drawings of the different kinds of leaves and give their names we could hang them up and could look at them any time."
"The leaf is the proper part to commence on, because it is the most important thing of every plant, or tree, or shrub."
"What, more important than the fruit or the flower, or the nut that grows on the tree?"
"That is just what I mean. When you smell the rich red flower of the rose, or look at the pure white petals of the lily, or the sweet-smelling blossoms of the orange or the jasmine, you are simply seeing or smelling leaves. The fruit itself, whether in the form of an apple, or a berry or a nut, is simply a form of leaf, a perfected form of the plant, or bush, or tree. Originally all these fruits, flowers and nuts were but leaves in an undeveloped state."
"I never heard of such a thing before."
"It is a subject treated of in botanical knowledge which is called Morphology, and the object is to show that every fruit and flower was developed, in accordance with a well-known law, from the particular shape or form of the leaf. We can go into that branch of the subject later on. What we now want is to know something about the shape of the leaf, so we can have a starting point. There are two particular things about leaves; one has reference to the shape of the leaf, and the other to the way in which the edges are formed. To simplify the explanation, the drawings which I make pertain only to the edges. That will be sufficient for one time.
"Look at Fig. 14. The edges are like the teeth of a saw. This is called the serrate leaf. The rose and the common nettle have such leaves.
"Fig. 15 shows a leaf with a saw tooth edge wherein the teeth themselves have a lot of little saw teeth, as in the nettle-leaved bell-flower, and this is called bi-serrate.
"Fig. 16 has very large, sharp teeth, not pointing in any particular direction, like the oak leaf. This is called the dentate, or tooth.
"Fig. 17 has rounded projections instead of angular teeth, and is called crenate. Ground ivy and horseradish have such leaves.