  This is the second of the two last papers by V. N. Gribov concluding his 20
year long study of the problem of quark confinement in QCD. In this paper the
analytic structure of quark and gluon Green's functions is investigated in the
framework of the theory of confinement based on the phenomenon of supercritical
binding of light quarks. The problem of unitarity in a confining theory is
discussed. The write-up remained unfinished and so it is presented here. The
author was planning to considerably extend the paper. The text was prepared for
publication by Yu. Dokshitzer, C. Ewerz, and J. Nyiri.
