Regulative development in a spiralian em
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Boyer, Barbara Conta
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Article
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1971
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John Wiley and Sons
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English
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Spiral cleavage and mosaicism are closely associated in the Annelida, Mollusca, and probably the polyclad Turbellaria, but the evolutionary history of these phenomena remains uncertain. The Acoela, the most primitive order of turbellarians, exhibit spiral cleavage but with the formation of duets of