Morphogenesis of the Small Pieces taken from Polyps and Strobilae in Aurelia aurita

Strobilation is a process in which a polyp makes segments and each of them becomes ephyra. The present study dealt with the morphogenesis of the pieces which were isolated from the different horizontal level of polyp and strobilae at different stages of strobilation in Aurelia. Any piece cut from polyp could easily reconstitute a complete polyp, but it from strobilae at advanced stage would not reform the one but alternatively gave rise to ephyra. Loss of such polyp reconstititing potency was found to be a graduation property from distal to proximal of the body. However, even in a certain segment that might form ephyra, if vertically cut into more smaller size, the small segment would not show a normal way to ephyra but resume polyp characteristics eventually. During the course of such transformation, the samll segment would bring about firstly a disto-proximal difference and followed by apperance of two or four tentacles, which may be an indication of re-establishment of a radial symmetry in it. Either process, the regneneration in polyp piece or the transformation from ephyra characteristics to polyp ones, should seem to involve cellular interactions by which reguratory mechanisms would be able to operate in reconstituting a whole or part of a whole. Morphological and biochemical events which may occur in the transformation of strobila piece seem to give us one of the appropriate opportunities in studies of cell differentiation and morphogenesis