SUMMARY

Previous conclusions as to the innervation of the integument of amphioxus are discussed, and it is shown that in addition to the system of free nerve-terminals de-cribed by Lele, Palmer, and Weddell (1958), the skin of certain regions of the body contains specialized sensory cells and encapsulated nerve-endings. The cells of origin of the free nerve-terminals in the skin are described, and it is shown that they fall into several morphologically different categories. In the light of these observations it is suggested that the innervation of the skin of amphioxus does not provide un-equivocal evidence for the view that the different cutaneous sensations are determined by different discharge patterns in the same fibres of the nerve-rami leading from the skin