We present a three-dimensional hybrid cellular automata (CA)/partial differential equation (PDE)
model that allows for the study of morphogenesis in simple cellular systems. We apply the model to
the cellular slime mold Dictyostelium discoideum "from single cells to crawling slug". Using simple local
interactions we can achieve the basic morphogenesis with only three processes: production of and
chemotaxis to cAMP and cellular adhesion. The interplay of these processes causes the amoebae to
spatially self-organize leading to the complex behaviour of stream and mound formation, cell sorting
and slug migration all without any change of parameters during the complete morphogenetic process