  By the method of invariant manifold, we investigate the Ito equation
numerically with high precision. By the numerical results, we can completely
determine the form of analytic soliton solutions for the Ito equation. In fact,
by the numerical data we have succeeded in deciding the analytic form of the
$\tau$-function, which is more general than the old assumptions. This may
suggest that we should think more deeply about what the soliton is.
