Experimental evidence justifying the selection of primary variables in ovum isthmic transport is evaluated. Peristaltic pumping alone cannot account for the observed ovum motions, however, the theory of pressure forcing of pellets through narrow tubes when combined with the dynamic and motile properties of the mucosal and muscular layers of the isthmus, appears capable of modeling the physiological mechanism. In this model the hormonally dependent tubal compliance is a controlling element of transport rate. The contractile activity statistically distributed both spatially and temporally, provides a persistent though irregular directionality to the movement.