[ 64 3 
final!, as having all its Parts complete, but motion- 
lefs, or in a State of Reft. 
XXXIV. 
Now the Heart is the firft Part that can have any 
Motion at all 5 and, being in a State of Reft, muft 
be fuppofed in a Medium between its Dilatation and 
Contraction. The firft: Motion in the Heart then 
will be a compulfory Motion, which is its c Diafiole ; 
and the firft Motion performed by itfelf will be its 
reftitutive Motion or Syftole. Till this is done, 
there probably can be no Accretion of Parts, becaufe 
nothing can be propell'd to the Extremities but by 
the Contraction of the Heart. And this is much 
earlier brought about than many Authors have ima- 
gined, and in the Manner following. 
XXXV. 
It is certain, that Fluids pafs from the Mother to 
the Child very early, by the Veins of the Funis utnr 
biiicaiisi and at length arrive at the Vena cava. 
The Auricles and Ventricles are now in a State of 
Reft ; but the Fluids falling into the right Auricle, 
with a Gravity and Force it was not liable to before, 
it is fill'd and dilated beyond its former Tone * 
whereby the mufcular Cells are laterally comprefled, 
and become longer by the diametrical Preffure, and 
the interftitial Air is alfo comprefled into narrower 
Limits than before, and the whole Auricle is upon 
the Stretch : Thus its c DiaJiole is compulfory. 
XXXVI. 
