in all respects a little Placenta , and all the difference between them is in number, name, and magnitude. Why Ruminants differ in this Particular from other Viviparous Animals, is beside the Subject of our present Enquiry. But the great Flux of Blood, which constantly follows upon drawing the Placenta from Women (which is frequently so great as to cost them their Lives) is as plain a demonstration to Reason of the Continuity of the Vessels, as Mr. Cowper 's Experiments is to the Eye.
I have heard it objected by very Learned Men, that if there were such a Continuity of Vessels, and such Transfusion of Blood, the Fœtus must necessarily perish through loss of Blood, upon the separation of the Placenta from the Uterus; but that, on the contrary, no visible Flux of Blood does follow while the Fœtus continues wrapt in the Membrane, in which Condition it may be kept alive some Hours. To this it may be answer'd, that the Circulation in the Fœtus, being deriv'd from the Mother, may be suppos'd wholly to cease upon the cutting off the Communication between them, till it is again renew'd more forcibly by Respiration. But if we allow the motion already impress'd upon the Blood to be sufficient to keep it going a little while; yet it must needs be so exceeding languid, that the meer resistance of the External Air must be more than enough to hinder any Efflux of Blood from a Fœtus before Respiration. How long Life may be preserv'd without an actual Circulation of the Blood, is a Question not of this place. But we have been convinc'd by many and notorious Observations and Experiments, that Life has been recover'd a long time after all tokens of Respiration, Circulation, or even Life it self, have disappear'd; so that we can't think the first Solution either impossible or improbable.
I expect to be told, that in the early Days of Gestation in Viviparous Animals, there is no Placenta , or any Adhesion