The Two Ways of Organizing Expository Material.

The various kinds of material discussed may be organized into paragraphs in 'two ways. One is the use of material all of one kind,, as, for instance, several repetitions of the same idea ; the other, the use of material of differ¬ent kinds. A single paragraph organized accord¬ing to the second of these methods may contain a definition of some term, an example, an analogy, a repetition of some thought in other terms,—all different varieties of expository material.
When paragraphs are studied for material and not for structure they fall into either of these two classes ; that is, the material used is homogeneous (of the same kind) or heterogeneous (of different kinds). In writing a paragraph in exposition the first question is that of material, the nature of which determines the type of structure to be used.