Effects of GABA and glycine applied electrophoretically were examined on bipolar cells in the carp retina. When applied at the outer plexiform layer, GABA produced a small depolarization in on-center cells, but a small hyperpolarization in off-center cells. These effects were concluded to be mediated by photoreceptor cells. When applied at the inner plexiform layer, GABA produced a hyperpolarization in on-center cells but no response in off-center cells. This response was resistant to Co2+ ions. Thus GABA is very like the inhibitory neurotransmitter from amacrine to on-center bipolar cells. Glycine, when applied in either layer, did not have a noticeable effect on either type of bipolar cells.