[ 2 33 ] 
euftachian valve which fpreads itfelf be¬ 
fore this orifice, clofes all that the dia¬ 
phragm had left open. At this moment 
as the left finus ceafes to be turged with 
blood, the iile difappears, and the blood 
of the fuperior cava not meeting any fur¬ 
ther obftacle, defcends and paffes freely 
into the ventricle. 
By this admirable mechanifm, the two 
oppofite currents of the fuperior and infe¬ 
rior cava are introduced into the ventricle 
at diff rent times and feparately, fo that 
one current does not interrupt the entrance 
of the other. 
The author has farther remarked, that 
the interior fur face of the whole auricle is 
divided into two parts, the limits of which 
are marked out by a different fabric. 
The fuperior has lacertuli, the arrange¬ 
ment of which is fuited for forcing the 
blood from below upwards, and the infe¬ 
rior part is difpofed in fuch a way as to 
impel 
