59 2 THE AMERICAN JOURNAL OF SOCIOLOGY
cessive recompounding of the highest organic compounds, under- goes a higher degree of organization, and protoplasm is evolved, which is capable of carrying the process on upward, and of producing the progressively higher and higher forms of life. The lowest of these forms consist of what are called unicellular organisms, which have the power of multiplication or increase of numbers, but are incapable of any higher development. They are called " protozoans," and represent the initial stage in organic development. The next step consists in the organic union of two or more, usually many, of these unicellular organisms into a multicellular organism. Such organisms are called " metazoans," and with this stage begins the most important class of organic structures, viz., tissues. All the organic forms with which any but the microscopist is familiar belong to this metazoic stage and present a great variety of tissues, with which everybody is more or less familiar.
I will not go farther with these illustrations from the inorganic and organic world; but it was essential, as will soon appear, to go thus far. Social structures are identical, in these fundamental aspects, with both inorganic and organic structures. They are the products of the interaction of antagonistic forces. They also pass from a primordial stage of great simplicity into a secondary, more complex stage, and these two stages are closely analogous to the protozoic and metazoic stages of biology. I call them the " protosocial " and " metasocial " stages, respectively.
If we set out with the simple propagating couple, we soon have the primitive family group consisting of the parents and children. The children are of both sexes, and they grow to maturity, pair off in one way or another, and produce families of the second order. These do the same, resulting in families of the third order, and so on. After a few generations the group assumes considerable size, and constitutes first a horde, and finally a clan. The clan at length becomes overgrown and splits up into several or many clans, separating more or less territorially, but usually adopting the rule of exogamy, and living on com- paratively peaceful terms at no great distance from one another. Their mode of reproduction is exactly analogous to the process
