70 BIOLOGY OF THE LABORATORY MOUSE 





"Epithelial cell layer 



— Stratum granulosum 



-Stratum germinativum 

 polygonal cells 



. i— — — Stratum germinativum 



basal cells 



r - **. — Lamina propria 



■ a — Degenerating 



epithelial cell layer 



Stratum corneum 



-Stratum germinativum 

 polygonal cells 



''^b'[*aAI^^^''* ^^■^''^"'"b^-Tciir''^"'"^ 



Fig. 37. — Photographs of vaginal epithelium of a mouse in different stages of the 

 estrous cycle. A. Proestrus. B. Estrus. {From Clauherg.) 



