2. (Bot.)
Defn: Filled with spongy pith; pithy. Medullary groove (Anat.), a groove, in the epiblast of the vertebrate blastoderm, the edges of which unite, making a tube (the medullary canal) from which the brain and spinal cord are developed. — Medullary rays (Bot.), the rays of cellular tissue seen in a transverse section of exogenous wood, which pass from the pith to the bark. — Medullary sheath (Anat.), the layer of white semifluid substance (myelin), between the primitive sheath and axis cylinder of a medullated nerve fiber.
MEDULLATED
Me*dul"la*ted, a. (Anat.)
Defn: Furnished with a medulla or marrow, or with a medullary sheath; as, a medullated nerve fiber.
MEDULLIN
Me*dul"lin, n. Etym: [Cf. F. médulline.] (Bot. Chem.)
Defn: A variety of lignin or cellulose found in the medulla, or pith, of certain plants. Cf. Lignin, and Cellulose.
MEDUSA
Me*du"sa, n. Etym: [L., fr. Gr.
1. (Class. Myth.)
Defn: The Gorgon; or one of the Gorgons whose hair was changed into serpents, after which all who looked upon her were turned into stone.
2. [pl. Medusae (.] (Zoöl.)