In developmental biology, modeling and simulation play an important role in understanding cellular interactions. In this paper a simple language, the Cell Programming Language (CPL), is suggested for writing programs that describe this behavior. Using these programs, it is possible to simulate and visualize intercellular behavior. CPL is used to model cellular segregation based upon the differential adhesion hypothesis. Results indicate that a high degree of segregation can be produced in a mixture of cells by allowing random motion. The engulfment of a tissue by a less adhesive tissue is also observed when the two tissues are placed in contact. Both these simulations utilize only local interactions and random motion of cells. Earlier simulations used long-range interactions to observe similar effects. The present simulations prove that random motion of cells can produce long-range effects.