THE SEXUAL ORGANS. 651 



the outer layers. After the sixth month, this origination of muscles 

 seems to cease ; at least in the twenty-sixth week, in the whole uterus I 

 have found nothing but the above-mentioned colossal fibre-cells, and 

 no longer any trace of their earlier forms. Like the muscles, the 

 fibrous tissue which unites them also increases, and towards the end of 

 pregnancy, occasionally exhibits distinct fibrils. Whilst the muscular 

 coat grows in this way, the mucous membrane has also undergone mani- 

 fold 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 lines, is softer, more lax, and redder, acquires more promi- 

 nent plicce, and is more distinctly defined from the muscular coat ; pecu- 

 liarities which, as time goes on, become more and more marked. Examined 

 microscopically, it is apparent, that not only are the vessels more dis- 

 tended, but also that an abundant new formation of connective tissue 

 has taken place in its parenchyma, and a considerable enlargement of 

 the utricular glands, which latter are, at this time, 2-3 lines long, 

 and 0-04-0-11, or, on the average, 0-08 of a line broad. As these 

 changes proceed, the greater part of the hypertrophied mucous mem- 

 brane is transformed into the well-known decidua vera, whilst another por- 

 tion, at the point of attachment of the ovum, is converted into the pla- 

 centa uterina, and by a growth from the border of this part, the reflexa 

 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 into wider follicles, the orifices 

 of which give rise to the appearance, as it were, of a cribriform perfora- 

 tion 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 of colossal fibre-cells with well-formed large nuclei, and, 

 particularly in the decidua vera, of vessels ; whilst in epithelium, except 

 in the first month, is no longer to be found upon the deciduce. The 

 mucous membrane of the cervix takes no part in the formation of the 

 deciduce, and retains its epithelium (without cilia) during the whole time 

 of pregnancy. It also, however, swells, and its mucous follicles, espe- 

 cially, enlarge and secrete the well-known mucous plug which fills up 

 the entire canal of the cervix. 



The serous coat also increases considerably in thickness, though not 

 to the same extent as the mucous membrane : whilst the thickening of 

 the uterine ligaments, particularly of the round ligaments, is very evi- 

 dent, and also depends upon changes in their smooth muscles similar to 

 those described in the muscles of the uterus, and probably also, upon an 

 increase of the transversely striated bundles. The growth of the 



