208 NORMAL HISTOLOGY. 



laminated epithelium covering the lower portion of 

 the canal and the portio vaginalis. The uterus is a 

 very vascular organ ; the mucous membrane is sup- 

 plied with a rich capillary plexus, which passes inward 

 close beneath the surface-epithelium. 



During menstruation the mucous membrane be- 

 comes thickened partly owing to the engorgement 

 of its blood-vessels, and partly to the accumulation 

 of fluid and lymph-cells in its interstices. The 

 uterine glands are enlarged, and their epithelium, 

 as well as that of the general surface of the cavity, 

 is swollen. To what extent the blood, which, mixed 

 with mucus and separated epithelium, is present 

 in the cavity at the menstrual period, is due to 

 the rupture of the engorged capillaries, and to 

 what extent to diapedesis, is not yet definitely 

 determined. 



TECHNIQUE. 



Section of Human Uterus. The uterus is cut into sev- 

 eral pieces, and hardened in Mailer's fluid. The organ 

 should be procured as soon as possible after death, since 

 the cilia of the lining epithelium are easily destroyed by 

 the decomposition which commences very early in the 

 uterine cavity. Sections perpendicular to the surface of 

 the mucous membrane are made from the cervix, and, in 

 the body, from the lower portions or from the vicinity of 

 the entrance of the Fallopian tubes, since here the uterine 

 glands are more uniformly arranged at right angles to 

 the surface. They are stained double and mounted in 

 balsam. 



