An attempt is made to derive the significant features of a mature hurricane eye in terms of a simplified model of the physical processes undergone by the air composing it. In particular, a quantitative relation is prescribed among the fields of motion, temperature, and humidity on the basis of assumptions concerning the exchange of mass and momentum between the eye and its surrounding cloud bands. The basic assumptions are that eye air mixes with the cloud wall on its descent; the latter is maintained by lower level outflow caused by unbalanced centrifugal and Coriolis forces, resulting from the incorporation into the eye of high cloud-wall momentum. Joint entrainment and angular momentum calculations for two hypothetical cases of stationary hurricanes of differing intensity show qualitative agreement in major features with existing incomplete observations and delineate a computational framework for real cases when available. Modifications of eye structure in moving storms are finally considered.