ceflity of placing the Human Heart, as well as thatof moft 
Quadrupeds, fo far from the Cet^er of the Body towards 
its upper part? It is for that end neceAlary the large Truaks^.icwfr^ 
oi d\^ Veins md Arteries ihbuld diur affociare eacixQcher ^^■'^'^^' ^^^- 
for if all the Blood fenc to the !6 /^er parts, by the De-^"^^* 
fcending Trunk of the Aorta, fhoaki reruni to the Heart 
again by one fingle Trunk fas it is lent ouc from thence J 
the Weight of fo much Blood in the \fcendiag Trunk of 
the Vena Cam, (Fig^ 6. C, C, A) (for io its lov/er Trunk is 
caird) would opppfp the force f he Heart could give it from 
the Arteries, and hinder its afcent : For this reafon the 
Fena Azygol Fig. 6, b ) or; fne furi^ is contriv'd to con- 
vey the Blood fent to the Mufeles of the Back and Thorax 
into the Defcei^ding Trunk of the Vem Ca%u ( ik B. A- ) 
above the Heart : Hence it's evident, more Blood comfs 
into the Heart: i by the 13efcendiog,< or upRQr Trunk of the 
Vena Cava^ \¥i^ ib. B, A. - thau; paffes oyi by the Afcending 
Trunks of the Nor does this quantity of Blood 
conveyed to the Heart by thQ Superior Trunk of the Cava^ 
feem without fome other defign in Nature, befides Tran- 
fpotting iit thither to free; thp i^^m/^^ Irom its 
Weight:) But perhaps lit M^as^qcceCary fb rnuch Blood 
fliould be ready there to joyn with the Chyle, (Fig. 6. ^f} 
for its better Mixture, before it reaches the ilight Auricle 
of the Heart. 
I might here add ttw Pe^cripqion of a -^cctflrar Vlihe I 
lately difcovered iin the Lifw^r Trimk <4 ri^e Pcna;Qv^^. near 
the Right Auricle of the Heart ^ but the Anncxt Figures 
have taken up too much room in thcfe Copper Plates ta 
infert it : For the fame reafon, the Figures pi lorn Con- 
trivances in the i^rtoief here mention d, -p^i;ticul^rly the • 
hSpermaticksj are omit ted: Thjs being what, pccuaxl to v,^y 
Thoughts at prefcntJ on this fuhjed, which is not to b^ 
lound (at leaft-not commonly^ in the Books of £i,.to:7fyT 
The greateft part of which have been added to th^fe Pa- 
pers, on their lying by me fince the Graver b.'r^an ih ? Fi- 
gures;' 
Uuuuuuu 2 Th: 
