involucrum

An enveloping sheath or envelope, such as the sheath of new bone that forms around a sequestrum.

In pathology, a wall of new osseous tissue inclosing the sequestrum in a case of necrosis.

In zoology, a kind of sheath or involucre about the bases of the thread-cells of acalephs.

In botany: Same as involucre.

Same as velum.

See Involucre.

A sheath which surrounds the base of the lasso cells in the Siphonophora.

A sheath that covers or envelopes, especially one that forms around the sequestrum of new bone