Information on the life cycle of Necturus has accumulated slowly. Naturalists long were uncertain as to whether they had adult animals, since Mitchill\u27s (1822) mistaken idea that they get to be two feet long was widely current. Lacepede (1807) believed that mudpuppies might be larval, and their adults unknown; Say (1818) that the mud puppy was the larva of the hellbender. Barton (1807) confused the mudpuppy and the hellbender. Gray (1857) was ... inclined for the present to consider the Proteus of the Lakes as a distinct kind of Batrachian, which is arrested in its development, and never reaches the perfect state. Cope (1866) said, The relation then between Necturus and Spelerpes is probably the same as that between Siredon and Amblystoma... ; and Kollman (1885) that the relation between Necturus and Batrachosops was the same as that between Axolotl and Amblystoma. Cox (1907) believed that members of the Proteidae undergo metamorphosis, ... the young being more or less unlike the adults. Necturus was described as ... a form arrested in development . Netting (1933) called Necturus the Peter Pan of salamanders, for it never grows up