Earthworm
Regeneration

Earthworms have the ability to regenerate lost segments, but this ability varies between species and depends on the extent of the damage. Stephenson (1930) devoted a chapter of his monograph to this topic, while G. E. Gates spent 20 years studying regeneration in a variety of species. But "because little interest was shown", Gates (1972) published only a few of his findings. These nevertheless show it is theoretically possible to grow two whole worms from a bisected specimen in certain species.

Gates's reports included:

An unidentified Tasmanian earthworm shown growing a replacement head has been reported.
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