  Various bacterial strains exhibit colonial branching patterns during growth
on poor substrates. These patterns reflect bacterial cooperative
self-organization and cybernetic processes of communication, regulation and
control employed during colonial development. One method of modeling is the
continuous, or coupled reaction-diffusion approach, in which continuous time
evolution equations describe the bacterial density and the concentration of the
relevant chemical fields. In the context of branching growth, this idea has
been pursued by a number of groups. We present an additional model which
includes a lubrication fluid excreted by the bacteria. We also add fields of
chemotactic agents to the other models. We then present a critique of this
whole enterprise with focus on the models' potential for revealing new
biological features.
