Epithelial cells reach maximum development. Outer layer of epithelial cells become cornified and sloughed into the lumen. In early estrus these cells retain their nuclei, but in later stages no nuclei visible and the cells are irregular, flat, cornified plates. The skin around the vaginal orifice becomes swollen. Metestrus Many corpora lutea, which secrete only for a very short time, and small follicles.
Epithelium continues vacuolar degeneration and replacement.
Leucocytes in stroma. Decrease in size and vascularity. Deeper layers of the estrous epithelium now line the lumen, the older, superficial layers having become cornified and sloughed off. Reduction of mitotic activity in epithelium. Leucocytes in stroma and migrating through the epithelium into the lumen.