A short-term (1-1.5 min) irrigation of the olfactory mucosa of the frog Rana temporaria with 0.1-0.15% Triton X-100 in Ringer''s solution led to the destruction of olfactory flagella but did not damage the olfactory knob and its flagellar basal bodies. Simultaneously, the generator potential of the olfactory cells electro-olfactogram (EOG) disappeared. The olfactory cells deprived of flagella were able to produce these organelles. This process began 2 or 3 h following the flagellum removal, proceeded in some stages and was completed within 2 or 3 days. During flagellum regeneration the ability of olfactory cells to generate the EOG was restored. This confirmed the presence of receptive sites on the flagellar surface.