The growing-and-decaying mode solution to the Davey-Stewartson equation are
presented, which describe the long time evolution of the Benjamin-Feir uns
table mode in two dimensions. A solution consisting of a line soliton and a
growing-and-decaying mode shows that the Benjamin-Feir unstable mode does
not destroy the structure of the line soliton. The breather solution and ra
tional growing-and-decaying mode solution are also presented. [S1063-651X(9
9)00708-4].