Bipolar Planarians in a Stock Culture

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Science  29 Nov 1963:
Vol. 142, Issue 3596, pp. 1187
DOI: 10.1126/science.142.3596.1187


Four long bipolar planarians were discovered in a stock culture of asexual Dugesia dorotocephala. Such worms have not been previously reported. Eyespots, auricles, and responses to stimuli were normal in each head-end, and functional pharynges were present. Worms in the stock culture had not been subjected to temperature variations, chemicals, or other experimentation. It is suggested that the axial gradient was effectively flattened by a normal head-inhibiting factor being unable to diffuse to the posterior end.