This is the normal, non-keratinizing squamous epithelium of the uterine ectocervix. The boundary between the basal, proliferating cells of the epithelium with the underlying stroma (the basement membrane) is smooth and continuous. The cells enlarge and then flatten as they move towards the lumen, while the nuclei shrink and become pyknotic. Mitotic figures are not evident up in the middle of the epithelial layer. (In house micrograph)