DECIDUA VERA OF FIRST STAGE. 



323 



outlines of the glands or gland spaces, gV and gl" , and by dotting the areas occu- 

 pied by the connective tissue. The blood-vessels are indicated by double out- 

 lines. The artery shown in the figure, owing to its spiral course, is cut repeatedly. 

 The figure demonstrates very clearly that the gland cavities are so arranged that 

 the decidua is divided into an upper compact layer and a lower cavernous layer, 

 the difference being due to the size and number of the gland cavities. The 

 amount of epithelium to be observed at this stage varies greatly. It is some- 



Comp. 



Cav. 



Muse. 



Fig. 184. — Vertical Section of a Human Uterus 

 (Decidua vera), One Month Pregnant. 



Comp, Compact layer. Cav, Cavernous layer. D, 

 Gland -duct. Art, Spiral artery. Gl, Spaces 

 occupied by epithelial glands. Muse, Muscularis. 

 (For clearness all the glandular epithelium has 

 been omitted from the drawing.) 



Fig. 185. — Human Uterus, One Month Preg- 

 nant. Section of Gland from the 

 Cavernous Layer, with the Epithelium 

 Partly Adherent to the Walls. X 445 

 diams. 



times wholly absent from the surface, in other cases absent or present in patches. 

 In the glands the epithelium has undergone many modifications. In some parts 

 the original cylinder epithelium of the glands is well preserved in patches, and 

 such patches of epithelium are found at every stage until after delivery. It has 

 been observed that these patches serve to regenerate the epithelium of the glands, 

 and by spreading from the glands on to the surface, to regenerate also the epithe- 

 lial covering of the uterine mucosa. But for the most part the glandular epi- 



