The process of wound repair in Udotea petiolata (Siphonales).

The process of wound repair is examined in the multiaxial thallus of Udotea petiolata. In response to cutting, the injured siphons form a plug, which quickly seals the wound surface. This plug is composed of a fibrillar substance, and of roundish bodies; the latter in unwounded siphons are present in the vacuole. A wound-wall is formed inside the plugs in every tested part of the thallus. Only the apical terminations of the fringe siphons are unable to form a complete wound repair. The composition and function of the two components are discussed.