  The Lagrange-Poincare equations of classical mechanics are cast into a field
theoretic context together with their associated constrained variational
principle. An integrability/reconstruction condition is established that
relates solutions of the original problem with those of the reduced problem.
The Kelvin-Noether theorem is formulated in this context. Applications to the
isoperimetric problem, the Skyrme model for meson interaction, metamorphosis
image dynamics, and molecular strands illustrate various aspects of the theory.
