III. The Leaf.
Derivation of word [26]
The Latin form 'folium' [41]
The Greek form 'petalos' [42]
Veins and ribs of leaves, to be usually summed under the term 'rib' [44]
Chemistry of leaves [46]
The nomenclature of the leaf consists, in botanical books, of little more than barbarous, and, for the general reader, totally useless attempts to describe their forms in Latin. But their forms are infinite and indescribable except by the pencil. I will give central types of form in the next volume of Proserpina; which, so that the reader sees and remembers, he may call anything he likes. But it is necessary that names should be assigned to certain classes of leaves which are essentially different from each other in character and tissue, not merely in form. Of these the two main divisions have been already given: but I will now add the less important ones which yet require distinct names.
I. Apolline.—Typically represented by the laurel [51]
II. Arethusan.—Represented by the alisma [52]