The Tube Feet of Starfishes as Autonomous Organs

Abstract

An attempt was made to discover the basis for the autonomy of these organs. Isolated feet which had been cut off and the feet of animals whose centers of coordination were anesthetized were found to respond freely to stimuli, pointing to an independent nervous system. Isolated feet cut in such a way as to destroy any continuity of direct nerves reacted to stimuli, showing that transmission still took place. For this investigation Asterias vulgaris* Verrill was used. Methylene blue "intra vitam" staining revealed a loose net lying in the deeper part of the epidermis and connected with what appear to be sense cells. This net resembles, and is probably comparable to, the "nerve-net" described in other animals.