  Migration of planetesimals from the feeding zone of the terrestrial planets,
which was divided into seven regions depending on the distance to the Sun, was
simulated. The influence of gravity of all planets was taken into account. In
some cases, the embryos of the terrestrial planets rather than the planets
themselves were considered; their masses were assumed to be 0.1 or 0.3 of the
current masses of the planets. The arrays of orbital elements of migrated
planetesimals were used to calculate the probabilities of their collisions with
the planets, the Moon, or their embryos. Based on our calculations, we drew
conclusions on the process of accumulation of the terrestrial planets. The
embryos of the terrestrial planets, the masses of which did not exceed a tenth
of the current planetary masses, accumulated planetesimals mainly from the
vicinity of their orbits. When planetesimals fell onto the embryos of the
terrestrial planets from the feeding zone of Jupiter and Saturn, these embryos
had not yet acquired the current masses of the planets, and the material of
this zone (including water and volatiles) could be accumulated in the inner
layers of the terrestrial planets. The inner layers of each of the terrestrial
planets were mainly formed from the material located in the vicinity of the
orbit of a certain planet. The outer layers of the Earth and Venus could
accumulate the same material for these two planets from different parts of the
feeding zone of the terrestrial planets. The Earth and Venus could acquire more
than half of their masses in 5 Myr. A relatively rapid growth of the bulk of
the Martian mass can be explained by the formation of Mars' embryo (the mass of
which is several times less than that of Mars) due to contraction of a rarefied
condensation.
