Eutelic organisms have a fixed number of somatic cells when they reach maturity, the exact number being relatively constant for any one species. This phenomenon is also referred to as cell constancy. Development proceeds by cell division until maturity; further growth occurs via cell enlargement only. This growth is known as auxetic growth. It is shown by members of the now obsolete phylum Aschelminthes. In some cases, individual organs show eutelic properties while the organism itself does not.[1]
