acellular layer

The corneal endothelium is attached to the rest of the cornea through Descemet's membrane, which is an acellular layer composed mostly of collagen.

Descemet's membrane (also posterior limiting membrane): a thin acellular layer that serves as the modified basement membrane of the corneal endothelium, from which the cells are derived.

The acellular layer of cementum is living tissue that does not incorporate cells into its structure and usually predominates on the coronal half of the root; cellular cementum occurs more frequently on the apical half.