  We present here the general transformation that leaves unchanged the form of
the field equations for perfect fluid Friedmann--Robertson--Walker and Bianchi
V cosmologies. The symmetries found can be used as algorithms for generating
new cosmological models from existing ones. A particular case of the general
transformation is used to illustrate the crucial role played by the number of
scalar fields in the occurrence of inflation. Related to this, we also study
the existence and stability of Bianchi V power law solutions.
