  It was previously shown that most of the superstrings can be obtained from
those with higher world-sheet supersymmetry as spontaneously broken phases. In
this paper, we show that the small $N=4$ superstring, which was left out of
this hierarchy of the universal string, can be obtained from the large $N=4$
strings. We also show that the $N=2$ string is a special vacuum of small $N=4$
string. Thus all the known superstring theories can be derived from a universal
string by spontaneous breakdown of supersymmetry.
