A quasiparticle model of the Bose fluid is developed which provides a simple understanding of the general first-order predictions of the quantum-statistical theory presented in the preceding papers of this series. The essence of the model is that there are two kinds of quasiparticles superimposed on a background sea of nonzero-momentum superfluid particles. It is out of this sea that superfluid quasiparticles, or holes, and normal-fluid quasiparticles are created. The normal fluid is composed entirely of quasiparticles. The results presented in this paper are only valid at temperatures such that the fraction ξ of zero-momentum (superfluid) bosons is appreciable, although ξ≠0 for all temperatures below the transition temperature inasmuch as Bose-Einstein condensation is assumed to be the underlying cause of the "super" properties of a Bose fluid. At T=0, only the zero-momentum bosons and the nonzero-momentum superfluid sea exist, there being no quasiparticles in this case. It is suggested that the excitations in helium ii measured by existing neutron scattering experiments correspond to the destruction of superfluid quasiparticles, and that the creation of normal-fluid quasiparticles should also be observable.