A possible sensory-motor neuron in Aplysia californica.

A granule-containing cell is described in the secretory epithelia of the accessory genital mass in Aplysia californica. The ciliated apical process of this cell protrudes into the lumen of the oviduct. The granule-containing basal region of the cell is drawn out into fine processes that resemble axons. Granule-filled dilatations of these axons are found directly under large secretory cells. On this basis, it is suggested that these cells fulfill the morphological criteria for sensory-motor cells, and this data will be used as a basis for microelectrode studies to confirm or deny the above suggestion.