  Is shown that any separable superreflexive Banach space X may be
isometrically embedded in a separable superreflexive Banach space Z=Z(X)
(which, in addition, is of the same type and cotype as X) such that its
conjugate admits a continuous surjection on each its subspace. This gives an
affirmative answer on S. Banach problem: Whether there exists a Banach space X,
non isomorphic to a Hilbert space, which admits a continuous linear surjection
on each its subspace and is essentially different from l_1?
