root sheath

A cuticular covering of the root of an organ, inner r. s. of a hair. A layer, in the root of a hair, lying immediately external to its cuticle and made uprot.'] of Henle's and Huxley's layers (q. v.), and a very delicate cuticle, outer r. s. of a hair. A layer of stratified epithelium, similar to the stratum Malpighii of the skin, immediately beneath the glo y membrane of a hair follicle.