  We develop a theory of polymers in a nematic solvent by exploiting an analogy
with two-dimensional quantum bosons at zero temperature. We argue that the
theory should also describe polymers in an {\sl isotropic} solvent. The dense
phase is analyzed in a Bogoliubov-like approximation, which assumes a broken
symmetry in the phase of the boson order parameter. We find a stiffening of the
longitudinal fluctuations of the nematic field, calculate the density-density
correlation function, and extend the analysis to the case of ferro- and
electrorheological fluids. The boson formalism is used to derive a simple
hydrodynamic theory which is indistinguishable from the corresponding theory of
polymer nematics in an isotropic solvent at long wavelengths. We also use
hydrodynamics to discuss the physical meaning of the boson order parameter. A
renormalization group treatment in the dilute limit shows that logarithmic
corrections to polymer wandering, predicted by de Gennes, are unaffected by
interpolymer interactions. A continuously variable Flory exponent appears for
polymers embedded in a {\sl two}-dimensional nematic solvent. We include free
polymer ends and hairpin configurations in the theory and show that hairpins
are described by an Ising-like symmetry-breaking term in the boson field
theory.
