Regeneration in the anemone, Sagartia luciae

Abstract

1) Tentacles regenerate at the oral end of aboral pieces cut at different levels; even on very short pieces. 2) The absence of the pedal disk in a piece does not effect the regeneration of tentacles, and the time required for the formation of a new disk is longer than that for new tentacles. 3) A cut in the column or in the oral ring does not cause a growth of tentacles unless, in the latter case, some hare been lost. If tentacles have been removed, new ones generally regenerate at the place of the cut, but they may be intercalated at intervals around the oral ring. 4) A pedal disk regenerates only at the aboral end of a piece, and tentacles only on the oral end of pieces (with the exception of a few heteromorphic tentacles on very small oral pieces). 5) Neither gravity nor contact effect the regeneration of tentacles, or the orientation of the individual. 6) The apparent change of orientation is only found in very small pieces, which, however, by means of rapid growth at the place of the cut ultimately assume the same orientation at that of the individuals from which they were cut, thus showing that even the smallest pieces have a definite polarity.