of Mufcular MotioWy whicli it exercifes in the Womb, it 
might without abfurdity be accounted for as a Graft upon, 
or Branch of the Mother. 
Concerning the immediate matter, and means of Life, and 
Nutrition, Authors are not agreed, nor is it the bufinefsof 
this place to reconcile, or decide their difFerenceSj but to 
account for the motion of the Blood thro the Veflels only. 
In order to this, ic will be neceffary to oblerve, that the 
Pulfation of the Heart in a Foetus is fo very weak and ob- 
fcure, and the motion of the Blood fo extream flow and 
languid, as to be fcarce, if at all, perceivable, as has been 
experienc'd in the Diffeafon of Puppies before Refpiration 
had. To produce fuch a feeble Palpitation, and creeping 
Motion, no greater force feems to be required, than may ^^ IfJ^^J^^r' 
deriv'd from the Communication between the Veffels of the Air. 
Mother and Fcetus in the Placenta* I am not ignorant, ^^^^^^ril&^ m 
divers very Learned Anatomifts (whom the Crowd haveim Jentid^fcUl 
plicicly followed) have abfolutely rejefteJ allCommunication 
between thefe Veffels. But, with fubmiffion to Great Au- 
thorities, I think they have afted arbitrarily, and without 
fufficient Warrant from Reafon or Experiment. For nei- 
ther are the Arguments which they bring againft it con- 
clufive, nor the Office which they affign to the Umbilical 
Veffels in lieu of it, proper, or natural to thofe Veffels, or 
the reality of the Fad made out by any fubftantial Reafons. 
Thofe that re|efl: this Communication ufually do it in fa- 
vour of one or both of thefe Opinions, that the Arteries 
of the Vtems do depofite a Nutritive juice, or a Juice im- 
pregnate with Air in the Placenta, which is fuck'd in by the 
TJmhilic4 Vein, and conveyed to the Fi^tus, for the necef- 
fary Ufes of Nutrition and Life. Now thofe that patro- 
nize either of thefe Opinions lead Nature an unneceffary 
dance. For if the Maternal Blood does really contain any 
fuch NntritioHTy or any fuch neceffary Aerial Particles, why 
fhou'd they be fepafated and extravafated, to be with diffi- 
culty received into the Vwbilical Vein, and again mixt with 
Eeeeeeee the 
