  We show how, in heterotic M-theory, an M5-brane in the 11-dimensional bulk
may end on an ``M9-brane'' boundary, the M5-brane boundary being a Yang
monopole 4-brane. This possibility suggests various novel 5-brane
configurations of heterotic M-theory, in particular a static M5-brane suspended
between the two M9-brane boundaries, for which we find the asymptotic heterotic
supergravity solution.
