This article analyses, both theoretically and empirically, the process of agglomeration associated with the most basic components of regional development. The growth of these basic components, denoted as 'condensation nuclei' and 'growth nuclei', are evidence of the power of forces of 'planning from below', working for development through local initiative or by attracting private investors and public institutions to a previously undeveloped region. The formation of the growth nuclei is likened to the formation of crystals in a saturated solution. Opportunities for growth of any new activity in a virgin region is tied to the accumulation of entrepreneurial and financial resources. Only when these reach the point of saturation will the developmental effort be crowned with success, and will new institutions and factories be established in the region. Resources then must be earmarked to ensure that the new initiatives are firmly established, and thus their presence lowers the 'concentration' of the solution. Therefore, the creation of additional initiatives slows down, or is halted altogether. According to this model, the growth rate will increase only after developmental pressures have accumulated sufficiently to push the region once again to the point of saturation. In contrast, however, to the chemical mechanism which usually operates in a closed system, the mechanism of growth nuclei formation operates in an open system, thus permitting leakages of human and financial resources. The development of growth nuclei were studied in four locations in the Israeli Negev region. In each of these locations, an incubation period for the idea, a certain resource which had reached the point of saturation and varying rates in the establishment of additional enterprises were found to exist.