The present paper reviews selected aspects of the Guliyev's hypothesis about
the massive celestial body at a distance of 250-400 AU from the Sun as well as
the factor of comets transfer. It is shown, that the conjecture of the point
around which cometary perihelia might be concentrated, is not consistent. On
the issue of perihelia distribution, priority should be given to the assumption
that there is a plane or planes around which the concentration takes place. A
total of 24 comet groups were investigated. In almost all cases there are
detected two types of planes or zones: the first one is very close to the
ecliptic, another one is about perpendicular to it and has the parameters: ip =
86{\deg}, {\Omega}p = 271.7{\deg}. The existence of the first area appears to
be related to the influence of giant planets. The Guliyev's hypothesis says
that there is a massive perturber in the second zone, at a distance of 250-400
AU. It shows that number of aphelia and distant nodes of cometary orbits in
this interval significantly exceeds the expected background. Analysis of the
angular parameters of the comets, calculated relative to the second plane
(reference point is the ascending node of a large circle) displays clear
patterns: shortage of comets near i' = 180{\deg}, excess of them near B'=
0{\deg} (ecliptic latitude of perihelion) and shortage near B'=-90{\deg}. The
analysis also shows irregularity of distant nodes, overpopulation of perihelion
longitudes in the range 350{\deg}-20{\deg}. Plotted distributions of aphelia
N(Q) and distant cometary nodes clearly indicate a perturbation of the natural
course near 300 AU. On the basis of collected cometary data, we have estimated
orbital elements of the hypothetical planetary body: a = 337 AU; e = 0.14;
{\omega} = 57{\deg}; {\Omega} = 272.7{\deg}; i = 86{\deg}