THE BASIS OF SOCIALITY 83
becoming dwarfed and by losing some of their highly devel- oped specialities. They have a tendency, like old varieties of plants, to assume some primitive or inferior type. Degeneracy or deterioration is, however, a relative term, return to a simpler form, i. e., a decrease in the differentiation of the plant, being often the successful means employed to secure a further lease of life. In the same way with human beings, poverty often places an embargo on differentiation. The highly developed individual, stricken with poverty, must needs forego the satisfaction of many tastes, and revert to a more common and primitive type. The utility of differentiation is, however, manifest on all sides. Death entered into the world with all its blessings, the old undying types giving place to the possibility of an ever- increasing variation. Sex entered, according to Weissmann, and increased the number of combinations and variations. Plants become annuals and biennials from a perennial condition. Changes in the plant and animal world meet the changes of the seasons, the temperature, the food supply, and the changing demands of the rest of the plant and animal world. Bailey sug- gestively remarks that the development of life took two diver- gent lines that of the circular arrangement of parts and that of bilateralism. The first line, developing in obedience to a peripheral or rotate type of organization, ends in the echino- derms and some of the mollusks. This type reached its zenith and, according to Cope, has left no line of descent. The pro- gressive and regnant type of animal life appeared in the vermes, or true worms, forms which are characterized by a two-sided or bilateral, and therefore more or less longitudinal, structure. By this means greater differentiation was made possible. A cephalic or head-forming evolution resulted from the bilateralism, and a specialization of the senses and central nervous system without parallel ensued. The extensive specialization of the sense and motor organs of the body, although marvelous, is carried to still greater limits by means of extra-organic instruments. The evolution of organs is continued in technic. 1
The differentiation being given, integration or organization 1 OTTO WIENER, Die Erweiterung unserer Sinne, Leipzig, 1900.
