a"d theace by a fhort and direift paffage thro* the Cava to 
the Heart ^ where paffing thro the Foramen Ovale to the 
Lefi Ventricle, and thro the Canalis Arteriofus from the 
Right and Pulmonary Artery, it is all deliver'd without co- 
ming at the Ij/ngs, to the Aorta, and from thence again 
the Umbilicai Arteries to the Veins of the Z)terus^ making 
a fort ot Epicycle to the main Circulation in the Mother. 
As this Opinion is favoured by the ftrudure and difpofi- 
tion of the Blood Veffels on both parrs/o there is nothing in 
it difficult to be conceived, or repugnant to experience. Late 
difcoveries have made it appear, that the Arteries and Vein? 
are continued Tubes, and that the latter contain nothing 
but what they receive from the former, and no reafon ap- 
pears why we fhou'd think this Method to be varied in the 
Placenta, On the other hand, if the Arteries ot the TJte^ 
rjKf were continued to the Veins of th^ fame pan, andthofe 
of the Fcett^s in like manner, without communicating with 
each other, their confluence in the Placenta feems to be al- 
together impertinent and of no ufe, and the Umbilical Ar- 
teries and Vein fram'd for no other fervice or* purpofe, 
than to give the Blood room for an idle Sally. 
Thus the reafonablenefs of this old Opinion may be vin- 
dicated, but the certainty of it refts upon ftronger proof. 
Mx Cpvpier^ to whofe happy Induftry we owe the Gonfir- 
matioQ of many Antient Difcoveries,^ and the benefit of 
fome new ones, has the honour to re-eftablifti this old, but\ 
loftg exploded 'Truth., For by pouring Mercury imo a- 
Branch ot the Uterine Artery of a Covo, that: went into one 
of the Cotyledones oi the Uterus^ he fiU'd thofe Branches of^ 
the Umbilical Veins, which went from that Cotyledon to 
the ]<!avel of iht Fatus ^ whieh: with a part of the Uterus 
he keeps prepar d by him. 
It wpu'd be a Weak objeftiop, to alledge that the Obfer- 
vation and Experiment being made on the Uterus of a Cowy 
the inference wou'd not hold from thenee to a Waman, the 
one being GlandHlifiroHSy and the othQt PUcentiferens ^ 
fince 
