According to Unstead, the smallest unit-areas of geographical study is defined as stows, which are grouped together to from larger areas, defined as tracts, sub-regions, minor regions and major regions. This scheme is not to deal with reciprocal relations between regions. Concepts of the smallest unit-area defined by some Gerln.ian ecologist as biotop or ecotop do not cover the primary life-spare that is to be a superorgaism.
It is W. Christaller who found the regional hierarchy between superorganism. There is a current tendency in Europe and America to study central places and their hinterlands. But the common measure of the importance of a place is not to be found. There are some differences between the functional grades of the regional center and its tributary area according to different criterion. Without this point, some striking similarities in attributes of the region are to be observed in the findings of geographers in Europe.
Tributary areas such as Gau, hundred, centena, seder and medieval market are identical in size with M. A. Kreis according to Christaller's rule. But now, our widest areas of daily life are connected with B. G. P. L Kreis. I can thence find a theory of spatial evolution. Christaller's theory that the distance between centers of each successive class increases by _??_ is to certain degree applicable to spatial evolution of interest area.
Godlund's rule of the cential evolution can not explain phenomenon of market falling and changes of regional arrangement caused by different systems of the traffic. There are some relics from the past self-contained area, those influence disturbs the glowing hierarchical order of the region. These disturbances are to be explained by the regional inertia. It is a urgent subjoct of social geographers, however, to fund delicate relations between grade of centrality and inner constructions of regional communities. From this point of view, geographers are able to find a proper field of “Soziogeograplie”.
