[ 2 3 ] 
Parts of the Body, whofe Shapes we are well ac- 
quainted with, the Reafonablenefs of this Opinion 
may appear yet ftronger. 
L. 
All Anatomifts agree, that the mufcular Fibres 
have their Rife from the Extremities of the Nerves 
and Biood-VelTels; every Fibre being fupplied by a 
Branch of a Nerve, and an Artery, and having alfo 
a Vein arifing from it. 
LL 
That the nervous Capillamenta are Cylinders 
is not denied by any one that I know of 5 and 
though the Arteries have been for a great while 
thought to be conical, yet the ingenious Dr. John 
Stephenjon * Fellow of the Royal College of Phyji - 
dans at Edinburgh hath evidently demonftrated the 
whole arterial Syftem to be Cylinders, frequently 
divided and fubdivided, ftill terminating in Numbers 
of fmall Cylinders, the Aggregate of which is always 
of greater Capacity than the Trunk or larger Cylin- 
der before the Ramification. 
L1I. 
May we not therefore very reafonably believe, 
from the Simplicity and Uniformity in all the Ope- 
rations of Nature, that the mufcular Fibres partake 
of 
* Medical ElTays, VoL V» 
