DECIDUA REFLEX A OF FIRST STAGE. 325 



tered between the cells are many sections of the processes. Occasionally it may 

 be seen that two cells are connected. Later on the decidual cells acquire 

 smoother and more rounded outlines, and appear to lose altogether their connec- 

 tions with one another. In the cavernous layer there are no decidual cells. 



Fig. 187. — Uterus One Month Pregnant ; Portion of the Compact Layer of the Decidua Seen 



in Vertical Section. 

 Coagl, Coagulum upon the surface. d,d', Decidual cells. X 445 diams. 



Decidua Reflexa of the First Stage. 



The decidua reflexa may be preserved in Zenker's fluid, Parker's fluid, or 

 picro-sulphuric acid. It should be hardened with the portions of the chorion 

 and chorionic villi adherent to it. It may be imbedded in celloidin and the 

 sections stained with alum hematoxylin and eosin, with Beale's carmine, or with 

 a so-called fibrin stain. 



As stated above (page 319), the presence of the decidua reflexa distinguishes 

 the first stage of pregnancy from the second, in which the reflexa is absent, hav- 

 ing disappeared by degeneration and absorption. To observe this process of the 



