UTERUS (DEVELOPMENT). 655 



uterine cavity, but the lower forms an attached pole of the little spherical chamber, which 

 base of greater or less breadth, which is conti- have the appearance of apertures recently 

 nuous in its entire circumference with the closed. Coste, in his beautiful series of illus- 

 parietal decidua. The two chambers are trations*, directs attention, in several figures, 

 totally distinct, and have no communication to a similar spot in the same situation, having 

 with each other. In aborted specimens, an the appearance of a recently closed aperture, 



or umbilicus. These traces of openings in 

 both the upper and lower poles of the sphere, 

 are of consequence, in reference to the expla- 

 nation which will be presently offered of the 



aperture may be sometimes seen in the base 

 or outer surface of the foetal chamber, or that 



part which has been torn away from the ute- 

 rine substance. In a very early specimen in 

 my possession, and also in another which I 

 have examined, one or more points are dis- 

 tinguishable also upon the upper or northern 



mode of formation of the decidua reflexa and 

 foetal chamber. 



The outer surface of this chamber is nearly 



Fig. 453. 



Uterus in the first month of gestation ; showing the formation oj the foetal cfiamber by the decidua reflexa^ 

 more advanced than in fig. 450. (After Coste.) 



, uterine walls laminated and traversed by numerous vessels; dv, decidua vera or developed lining 

 membrane of the uterus, the uterine glands or canals being much enlarged ; d r, decidua reflexa, in which 

 lies o, the ovum, at this stage often still unattached ; c, corpus luteum. 



smooth. Upon it, however, are seen the 

 orifices of numerous uterine glands. These 

 are usually wanting near the centre, or um- 



bilicus, but become more distinct towards the 



* Histoire Gene'rale et Particuliere du Developpe- 

 ment des Corps Organises. 



