??? ?? ?? ?? ???? ????? ????? ??? ?? ???? ???? ????? ??????? ?????? ???? ??, ?????? ????? ?? ?? ??????????? ??????? ???? ??.??? ???? ?????? ????? ?? ?? ?? ?????? ?? ??? ???? ?? ??? ??, ?? ?????????? ?? ???? ???.Nervous system of the generic bilaterian animal, in the form of a nerve twine with segmental enlargements, as well as a "brain" in the entr