Slide DMS181 [Cervix-vagina, monkey, H&E]. Note the noncornified stratified squamous epithelium of the vagina and vaginal portion of the cervix ("ectocervix"). Find the well developed cervical mucous glands and the abrupt change of stratified squamous to simple columnar epithelium near the external os of the cervical canal, the junction between endocervix and ectocervix. This region of epithelial transition is clinically important since it is here that many carcinomas of the cervix develop.