The slope of vertical incidence VHF backscattered power profiles from the stratosphere can be deduced from atmospheric stability profiles in conjunction with a recently-developed model of backscattering from horizontally-stratified refractivity structure in the clear air. The close resemblance of these theoretical profiles to profiles obtained from a number of different locations using the (MST) Doppler radar technique shows that vertical-incidence VHF backscattering in the stratosphere arises from stable, horizontal laminae of radio refractive index that 1) have horizontal dimensions of many tens of meters, and 2) are distributed randomly throughout the stratosphere.