The initial velocity of sporangia discharged by Pilobolus kleinii, a coorophilous phycomycete, was determined by the use of an oscilloscope to measure the time interval between (a) successive interruption of 2 beams of light by a sporangium or (b) signals from phonograph cartridge transducers actuated by the discharge or impact of a sporangium. The initial velocity of 100 sporangia determined by the latter technique ranged from 4.7-27.5 m/second with a mean of 10.8 m/second. There was little correlation between the velocity and diameter of sporangia.