260 SPECIAL HISTOLOGY. 



and towards the end of pregnancy, occasionally exhibits distinct 

 fibrils. Whilst the muscular coat grows in this way, the 

 mucous membrane has also undergone manifold changes. It 

 is in it, especially, that the metamorphoses of the gravid uterus 

 commence, seeing that as early as the second week, it becomes 

 thickened to 2 — 3'", is softer, more lax, and redder, acquires 

 more prominent plicae, and is more distinctly defined from the 

 muscular coat ; peculiarities which, as time goes on, become 

 more and more marked. Examined microscopically, it is ap- 

 parent, that not only are the vessels more distended, but also 

 that an abundant new formation of connective tissue has taken 

 Fig. 2G9. place in its parenchyma, and a considerable 



enlargement of the utricular glands, which 

 latter are, at this time, 2 — 3'" long, and 

 004 — 0*11'" broad, or, on the average, 

 O'OS"'. As these chauges proceed, the 

 greater part of the hypertrophied mucous 

 membrane is transformed into the well- 

 known decidua vera, whilst another por- 

 tion, at the point of attachment of the 

 ovum, is converted into the placenta uterina, 

 and by a growth from the border of this 

 part, the reflecca is produced around the 

 ovum ; processes of which this is not the 

 place to speak farther. It can only be 

 remarked that the utricular glands, in the 

 decidua vera, are gradually converted iuto 

 wider follicles, the orifices of which give rise 

 to the appearance, as it were, of a cribri- 

 form perforation in that membrane and the 

 border of the reflexa; and moreover, that the 

 deciduce, from the second month onwards, 

 though gradually diminishing, it is true, in 

 thickness, nevertheless, on account of the 

 enlargement of the internal surface of the 

 uterus, are still far from ceasing to increase in bulk; and 

 lastly, that their tissue at all times consists of larger and 

 smaller, round cells, with large, often compound nuclei, in part 



Fig. 269. A uterine gland from a Woman in the first pregnancy, eight days after 

 conception. 



