240 CHARLES R. STOCKARD AND G. N. PAPANICOLAOU 



away from the wall of the uterus and vagina (figs. 15, 16 and 17). 

 But it probably continues also after the cells are free in the lumen 

 of the vagina. The dissolving power of the leucocytes, which 

 probably causes the liquefaction of the cheesy mass of epithehal 

 cells is shown very well when leucocytes are seen within a cell 

 and the nucleus is beginning to dissolve. The nucleus is appar- 

 ently digested and dissolved by coming in contact with the 

 leucocyte without being at all engulfed or enclosed within the 

 smaller body of the leucocyte. 



As the third stage appoaches its end the material within the 

 vagina is a thin fluid containing a great number of leucocytes 

 as well as many epithelial cells of the second stage some of which 

 contain leucocytes within their bodies. Such leucocyte con- 

 taining cells are strikingly typical of the third stage. The 

 leucocytes within these cells as would be expected very soon 

 show signs of degeneration never staining so clearly as the free 

 outside ones. 



The fourth stage shows the same condition as the preceding 

 but often at this time a slight hemorrhage takes place, though 

 this does not always occur. A microscopical examination of the 

 hemorrhagic fluid shows in addition to the great number of red 

 blood corpuscles, a large number of leucocytes and also desqua- 

 mated cells of the second stage, some of which are penetrated by 

 leucocytes (fig. 9) . Sometimes red blood corpuscles are enclosed 

 within the bodies of the leucocytes and digested, this is probably 

 a truly phagocytic action and not entirely the same as their 

 dissolving effect on the neighboring epithelial cells within the 

 fluid. 



The presence of the leucocytes is not alone confined to the heat 

 period but an abundant quantity of them is also to be foiind in 

 the lumen of the vagina during the dioestrum. The only time 

 that leucocytes are absent from the vaginal lumen is during the 

 first and second stage described above at the beginning of the 

 oestrus. Throughout the first week after heat the little fluid 

 which exists in the vagina contains chiefly leucocytes and a few 

 atypical desquamated cells. During the second week the num- 

 ber of epithelial cells increases more and more and among these 



