  We discuss, in the context of M(atrix) theory, the creation of a membrane
suspendend between two longitudinal five-branes when they cross each other. It
is shown that the membrane creation is closely related to the degrees of
freedom in the off-diagonal blocks which are related via dualities to the
chiral fermionic zero mode on a 0-8 string. In the dual system of a D0-brane
and a D8-brane in type \IIA theory the half-integral charges associated with
the ``half''-strings are found to be connected to the well-known fermion-number
fractionalization in the presence of a fermionic zero mode. At sufficiently
short distances, the effective potential between the two five-branes is
dominated by the zero mode contribution to the vacuum energy.
