258 NORMAL PARTURITION. 



takes place in a remarkably brief period in some animals. With the 

 Bitch, Cat, and Rabbit, as with woman, the whole of the glandular layer 

 of the membrane corresponding to the insertion of the foetal placenta — 

 the decidua vera — is completely detached and eliminated. 



In Ruminants the cotyledons, which had gradually acquirec^uch large 

 dimensions during pr*egnancy, shrink, their follicular receptacles contract 

 so as to be scarcely visible to the naked eye, and many of these maternal 

 placentse even appear to subside altogether, or to be reduced to exceed- 

 ingly small proportions. With Solipeds and the Sow, which have a 

 diffused placenta, the follicles which received the placental papillae of the 

 chorion also disappear; and the membrane, greatly thinned, assumes its 

 ordinary ridged appearamce, though the ridges or folds are larger and 

 more numerous than before conception. In a Mare killed eighteen or 

 twenty hours after parturition, Ercolani found the maternal portion of the 

 placenta reduced to one-half its thickness ; its color, instead of being a 

 dull red, had become yellowish ; the follicles, from being one to two 

 millimetres in length, were reduced ta one and half a millimetre, and the 

 capillary network around them was no longer visible. 



The evacuation of the detached elements is accompanied by an ap- 

 parently large mucous secretion, which, often sanguinolent, constitutes 

 what we have described as the "lochia." 



Finally, a new^ epithelium is formed in the place of that which has been 

 shed, and the uterine interior presents the appearance it had before im- 

 pregnation. According to Friedlander, the formation of the new mucous 

 membrane takes place in the following manner : — All that has remained 

 behind of the cellular layer richly infiltrated with blood, as well as the 

 upper portions of the glandular layer, gradually exfoliates and is dis- 

 charged in the lochia. The flatly compressed glandular tubes situated 

 close to the muscular coat are opened up, and their cylindrical epithelium 

 forms the new mucous epithelium of the internal surface of the uterus. 

 The connective tissue situated between the tubular glands, accordingly 

 proliferates, and becomes reorganized. In consequence of the increase 

 in thickness of the mucous membrane, the previous shallow depressions 

 of the epithelium are deepened, and in that way the uterine glands are 

 also reformed in the new mucous membrane. 



Coincidently with this return to small proportions, the uterine cervix 

 also regains its former shape. During the passage of the foetus, in process 

 of dilatation the os and vagina form a continuous canal without any inter- 

 ruption, and the cervix is effaced. Immediately after the fcetus has 

 passed through, however, the .latter reappears, the os is closed, and the 

 uterus and vagina are again separated by the sphincter-like ring which 

 the uterine neck exhibits in the cavity of the latter. The cervix is at this 

 time soft and flabby, and the os, not entirely closed, is readily dilated by 

 the fingers. But it gradually contracts and closes, as its texture becomes 

 firmer, and in doing so it elongates towards the vagina, into which it pro- 

 jects, until it has regained its natural form and consistence ; though it is 

 always shorter and less regular in shape, particularly attheos, in animals 

 which have had several young, than in those which have never been 

 pregnant. The uterus itself does not completely assume the dimensions 

 it had in non-pregnant animals, but is always larger after it has contained 

 one or more foetuses. 



It may be noted that the broad ligaments of the uterus become short- 

 ened after parturition, and consequently raise the organ towards the 



