The model of Reeve and Rycroft (176) for the generation of whistler precursors is shown to be a special case f a mechanism by which from tropical lightning may be directed into the plasma-sphere so as to be able to resonate with energetic electrons just inside the plasmapause. The results of such a wave-particle interaction would b (1) to trigger VLF emissions which may under certain conditions be received on the ground as apparently spontaneous emissions and (2) to reduce the pitch angle of the resonant electrons, causing them to be precipitated into the atmosphere at the foot of the field line just inside the plasmapause. Such precipitating electrons could significantly contribute, by secondary ionization, to the maintenance of the bottom side ionosphere at night.