1843 R. Owen ii. 25 The very step which the Infusoria take beyond the primitive cell-stage invests them with a specific character as independent and distinct in its nature as that of the highest and most complicated organisms.
1878 7 Dec. 803/2 There was an arrest of development of the hair at the cell stage.
2007 302 335 (caption) Numbers at the top of the diagram indicate the cell stage.