CHANGES IN THE UTERUS. 



49 



inner surface to the vascular layer, so that a vertical section of the membrane exhibits 

 them cut quite as often obliquely or transversely as longitudinally. They are also 

 generally dilated, but the dilatation is by far most marked at the mouths of the 

 glands, which come thus to have a funnel-like shape, and in the deeper part of the 

 membrane, where the dilatations look in sections like a series of cavities, lined by 

 cubical or flattened epithelium, and separated from one another by a relatively 

 small amount of interglandular substance. This gives a spongy appearance to the 

 part in question, and it has been accordingly termed the stratum sponyiosum of 

 the decidua (fig. 51*, B, sp). The deepest part of the glands, that, namely, which is 

 in contact with and is imbedded in the superficial portion of the muscular coat, does 

 not share in this dilatation, and its epithelium also retains the columnar character. 

 The part of each gland between the funnel-shaped mouth and the dilatations above 

 described, also becomes enlarged, but not to so great an extent, the hypertrophy of 

 the mucous membrane being here chiefly confined to the interglandular tissue, which 

 becomes filled with large epithelium-like cells (decidual cells of Friedlander) and 

 with numerous and large capillary blood-vessels. This layer of the decidua has 

 been termed the stratum compadum in contradistinction to the stratum spongiosum 

 external to it (fig. 51*, B, c). 



After the fifth month, by which time the great increase in size of the ovum with 

 its contained embryo has brought the decidua reflexa into close contact with the 

 decidua vera, the latter begins to undergo an atrophic process, the result to all 

 appearance of the compression and distension to which it is thus subjected. Its 

 tissue becomes thinner and less vascular, and both the funnel-shaped mouths of the 

 glands and those parts of the glands which run through the stratum compactum 

 become gradually obliterated, so that eventually hardly any trace remains. In the 



Fig. 52. DIAGRAMMATIC SECTION THROUGH THE 



AT THE EDGE OP THE PLACENTA (from Kundrat and 

 Engelmann). 



c, sp, m, as in fig. 51*, B ; d v, decidua vera ; d s, decidua 

 serotina ; d r, decidua reflexa. 



stratum spongiosum the spaces which have 

 resulted from the dilatation of the gland tubes 

 lose the lining epithelium, and become flattened 

 out conformably to the surface, so that they now 

 appear as a layer of compressed lacunae, sepa- 

 rated by thin fibrous trabeculse (fig. 52, sp.). 



Similar changes occur in the decidua reflexa. 

 That this is truly a fold of mucous membrane is 

 evidenced by the fact that gland tubes can be 

 seen to open upon both its surfaces. These gland 

 tubes early become enlarged, and acquire an 



oblique or tortuous course, with dilatations in their deeper parts, i.e., in the middle 

 of the thickness of the d. reflexa, so as to form here also a sort of spongy tissue. 

 But the decidua reflexa sooner becomes expanded by the growing ovum into a 

 relatively thin membrane, and the atrophic changes in the glands occur at an 

 earlier stage, so that by the time that it has coalesced with the decidua vera hardly 

 any traces of them can be discerned. 



In the decidua serotina (placental decidua) similar changes have been described 

 in the glands, the final result being the formation of a spongy layer, with irregular 

 clefts flattened out conformably to the surface, and from which the epithelium has 

 entirely disappeared, accompanied by complete atrophy and disappearance of all the 

 parts of the glands which are superficial to this layer, the only portions which 

 remain nearly unaltered being the deepest parts of the tubes, which are partly 



VOL. I. JE 



