  There are well-known constructions of integrable systems which are chains of
infinitely many copies of the equations of the KP hierarchy ``glued'' together
with some additional variables, e.g., the modified KP hierarchy. Another
interpretation of the latter, in terms of infinite matrices, is called the
1-Toda lattice hierarchy. One way infinite reduction of this hierarchy has all
solutions in the form of sequences of expanding Wronskians. We define another
chain of the KP equations, also with solutions of the Wronsksian type, which is
characterized by the property to stabilize with respect to a gradation. Under
some constraints imposed, the tau functions of the chain are the tau functions
associated with the Kontsevich integrals.
