234 CHARLES R. STOCKARD AND GEORGE N. PAPANI.COLAOU. 



connection between the mucosa and the subjacent connective 

 tissue over extensive areas. This reaction is taking place a 

 few hours after copulation during the latter part of stage one 

 and throughout stage two of our description. A few hours later, 

 during stage three, the leucocytes have made still further progress 

 in their invasion of the mucosa and the destruction of its con- 

 nection with underlying tissues. In certain sections of the uterus 

 the entire mucosa filled with immense numbers of leucocytes is 

 completely separated from the uterine wall and lies within the 

 lumen, while in other regions the epithelium is loosely connected 

 but still hanging to the wall. This disconnected and degenerat- 

 ing mucosa loaded with leucocytes breaks into small fragments 

 during the fourth stage and is expelled from the uterus and 

 vagina, while a new mucosa begins to regenerate from the 

 mouths and the regions about the uterine glands and from the 

 deeper layers of the vaginal epithelium. This is the fate of the 

 mucosa when no copulation has taken place. 



There is, then, no pathological " vaginite exfoliante" due to an 

 irritation of the vaginal wall by the seminal fluid as Lataste 

 thought. But a simple periodic cestrous breaking down of the 

 uterine wall under leucocyte invasion, entirely independent of 

 whether copulation takes place or not. 



When copulation has occurred the loss of the epithelium 

 follows a somewhat different course. Immediately after copula- 

 tion the coagulated seminal fluid forms a mass within the lumen 

 of the vagina and partly extending into the uterus. Around this 

 mass the mucosa forms a close fitting envelope, thus preventing 

 its early dislocation. The envelope serves to retain the plug in 

 the vagina until the fourth stage of the oestrous cycle at which 

 time the enveloping epithelium becomes completely separated 

 from the vaginal wall by the dissolving effects of the leucocytes. 

 The epithelium is now expelled as one continuous tube forming 

 the cover around the vaginal plug instead of slufifing off in smaller 

 pieces as occurs during the fourth stage when a copulation has 

 not occurred. However, the vaginal epithelium may occasionally 

 be shed en masse without copulation. In one striking case the 

 epithelium was pulled out of the vagina as a conical sheath, enclos- 

 ing the speculum that had been introduced for examination. 



