The model of the bands recently proposed by Slonczewski and Weiss for graphite single crystals is described in some detail. It is then applied to a study of the cyclotron resonance absorption in graphite, taking into account plasma effects. This theory is then compared to the recent experimental data of Galt et al. The comparison leads to the conclusion that the charge carriers consist of holes with effective masses ranging from $0.066m$ to $0.054m$, and electrons with effective masses from $0.054m$ to 0. The present information on the band structure of graphite is gathered in the conclusion.