Bot. [ad. mod.L. colesula, irreg. dim. of Gr. κολεός sheath.] The name given by Necker to the small membranous sheath enclosing the spore-sac of liverworts; the perianthium.
1882. B. Carrington, in Encycl. Brit., XIV. 718. On section of the colesule a number of minute … bodies are found.
