  There are two sources of the factorial large-order behavior of a typical
perturbative series. First, the number of the different Feynman diagrams may be
large; second, there are abnormally large diagrams known as renormalons. It is
well known that the large combinatorial number of diagrams is described by
instanton-type solutions of the classical equations. We demonstrate that from
the functional-integral viewpoint the renormalons do not correspond to a
particular configuration but manifest themselves as dilatation modes in the
functional space.
