the world > life > biology > substance > cell > parts of cell > [noun] > wall or membranes > elements of (3)
sheath1884
A sheath-like covering. Applied to various animal and vegetable structures. Botany. ‘A limiting layer of surrounding cellular tissue’ (B. D. Jackson G…
sacculus1964
Microbiology. A bag-shaped macromolecule present as a structural element in the cell walls of some bacteria.