Vortex-line models for dual strings

We call attention to the possibility of constructing field theories for the dual string. As an example, we show that a Higgs type of Lagrangian allows for vortex-line solutions, in analogy with the vortex lines in a type II superconductor. These vortex lines can approximately be identified with the Nambu string. In the strong coupling limit we speculate that the vortex lines make up all low energy phenomena. It turns out that this strong coupling limit is "super quantum mechanical" in the sense that the typical action of the theory is very small in comparison with Plank's constant.