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Webster 1913 Edition

(spŭn′jĭn)

Noun.

(Physiol. Chem.)

The chemical basis of sponge tissue, a nitrogenous, hornlike substance which on decomposition with sulphuric acid yields leucin and glycocoll.

spongin ‎(plural spongins)

A horny, sulfur-containing protein related to keratin that forms the skeletal structure of certain classes of sponges proteinaceous compounds of which the spicules in Demospongiae are composed.