  We use a phase space description to (re)derive a first order form of the
Born-Infeld action for D-branes. This derivation also makes it possible to
consider the limit where the tension of the D-brane goes to zero. We find that
in this limit, which can be considered to be the strong coupling limit of the
fundamental string theory, the world-volume of the D-brane generically splits
into a collection of tensile strings.
